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change luan:web to luan:http
author Franklin Schmidt <fschmidt@gmail.com>
date Fri, 15 May 2015 17:43:13 -0600
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1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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2 <html>
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4 <head>
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5 <title>Luan Reference Manual</title>
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6 <link rel="stylesheet" type="text/css" href="lua.css">
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7 <link rel="stylesheet" type="text/css" href="manual.css">
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8 <META HTTP-EQUIV="content-type" CONTENT="text/html; charset=iso-8859-1">
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9 </head>
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11 <body>
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13 <hr>
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14 <h1 class="main">
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15 Luan Reference Manual
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16 </h1>
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18 <P>
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19 The reference manual is the official definition of the Luan language.
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20
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21 <p>
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22 <small>
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23 Original Copyright &copy; 2011&ndash;2013 Lua.org, PUC-Rio.
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24 Freely available under the terms of the
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25 <a href="http://www.lua.org/license.html">Lua license</a>.
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26 Modified for Luan in 2014.
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27 </small>
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28 <hr>
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29 <p>
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32 <!-- ====================================================================== -->
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33 <p>
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35 <!-- $Id: manual.of,v 1.103 2013/03/14 18:51:56 roberto Exp $ -->
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38 <H2><A NAME="contents">Contents</A></H2>
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39 <UL style="padding: 0">
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40 <LI><A HREF="#1">1 &ndash; Introduction</A>
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41 <P>
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42 <LI><A HREF="#2">2 &ndash; Basic Concepts</A>
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43 <UL>
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44 <LI><A HREF="#2.1">2.1 &ndash; Values and Types</A>
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45 <LI><A HREF="#2.2">2.2 &ndash; Environments and the Global Environment</A>
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46 <LI><A HREF="#2.3">2.3 &ndash; Error Handling</A>
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47 <LI><A HREF="#2.4">2.4 &ndash; Metatables and Metamethods</A>
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48 <LI><A HREF="#2.5">2.5 &ndash; Garbage Collection</A>
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49 <UL>
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50 <LI><A HREF="#2.5.1">2.5.1 &ndash; Garbage-Collection Metamethods</A>
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51 <LI><A HREF="#2.5.2">2.5.2 &ndash; Weak Tables</A>
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52 </UL>
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53 <LI><A HREF="#2.6">2.6 &ndash; Coroutines</A>
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54 </UL>
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55 <P>
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56 <LI><A HREF="#3">3 &ndash; The Language</A>
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57 <UL>
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58 <LI><A HREF="#3.1">3.1 &ndash; Lexical Conventions</A>
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59 <LI><A HREF="#3.2">3.2 &ndash; Variables</A>
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60 <LI><A HREF="#3.3">3.3 &ndash; Statements</A>
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61 <UL>
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62 <LI><A HREF="#3.3.1">3.3.1 &ndash; Blocks</A>
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63 <LI><A HREF="#3.3.2">3.3.2 &ndash; Chunks</A>
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64 <LI><A HREF="#3.3.3">3.3.3 &ndash; Assignment</A>
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65 <LI><A HREF="#3.3.4">3.3.4 &ndash; Control Structures</A>
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66 <LI><A HREF="#3.3.5">3.3.5 &ndash; For Statement</A>
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67 <LI><A HREF="#3.3.6">3.3.6 &ndash; Function Calls as Statements</A>
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68 <LI><A HREF="#3.3.7">3.3.7 &ndash; Local Declarations</A>
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69 <LI><A HREF="#3.3.8">3.3.8 &ndash; Or/And Statements</A>
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70 </UL>
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71 <LI><A HREF="#3.4">3.4 &ndash; Expressions</A>
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72 <UL>
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73 <LI><A HREF="#3.4.1">3.4.1 &ndash; Arithmetic Operators</A>
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74 <LI><A HREF="#3.4.2">3.4.2 &ndash; Coercion</A>
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75 <LI><A HREF="#3.4.3">3.4.3 &ndash; Relational Operators</A>
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76 <LI><A HREF="#3.4.4">3.4.4 &ndash; Logical Operators</A>
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77 <LI><A HREF="#3.4.5">3.4.5 &ndash; Concatenation</A>
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78 <LI><A HREF="#3.4.6">3.4.6 &ndash; The Length Operator</A>
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79 <LI><A HREF="#3.4.7">3.4.7 &ndash; Precedence</A>
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80 <LI><A HREF="#3.4.8">3.4.8 &ndash; Table Constructors</A>
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81 <LI><A HREF="#3.4.9">3.4.9 &ndash; Function Calls</A>
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82 <LI><A HREF="#3.4.10">3.4.10 &ndash; Function Definitions</A>
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83 </UL>
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84 <LI><A HREF="#3.5">3.5 &ndash; Visibility Rules</A>
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85 </UL>
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86 <P>
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87 <LI><A HREF="#4">4 &ndash; The Application Program Interface</A>
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88 <P>
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89 <LI><A HREF="#5">5 &ndash; The Auxiliary Library</A>
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90 <P>
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91 <LI><A HREF="#6">6 &ndash; Standard Libraries</A>
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92 <UL>
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93 <LI><A HREF="#6.1">6.1 &ndash; Basic Functions</A>
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94 <LI><A HREF="#6.2">6.2 &ndash; Coroutine Manipulation</A>
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95 <LI><A HREF="#6.3">6.3 &ndash; Modules</A>
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96 <LI><A HREF="#6.4">6.4 &ndash; String Manipulation</A>
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97 <UL>
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98 <LI><A HREF="#6.4.1">6.4.1 &ndash; Patterns</A>
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99 </UL>
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100 <LI><A HREF="#6.5">6.5 &ndash; Table Manipulation</A>
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101 <LI><A HREF="#6.6">6.6 &ndash; Mathematical Functions</A>
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102 <LI><A HREF="#6.7">6.7 &ndash; Bitwise Operations</A>
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103 <LI><A HREF="#6.8">6.8 &ndash; Input and Output Facilities</A>
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104 <LI><A HREF="#6.9">6.9 &ndash; Operating System Facilities</A>
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105 <LI><A HREF="#6.10">6.10 &ndash; The Debug Library</A>
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106 </UL>
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107 <P>
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108 <LI><A HREF="#7">7 &ndash; Lua Standalone</A>
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109 <P>
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110 <LI><A HREF="#8">8 &ndash; Incompatibilities with the Previous Version</A>
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111 <UL>
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112 <LI><A HREF="#8.1">8.1 &ndash; Changes in the Language</A>
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113 <LI><A HREF="#8.2">8.2 &ndash; Changes in the Libraries</A>
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114 <LI><A HREF="#8.3">8.3 &ndash; Changes in the API</A>
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115 </UL>
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116 <P>
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117 <LI><A HREF="#9">9 &ndash; The Complete Syntax of Lua</A>
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118 </UL>
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119
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120
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121 <h1>1 &ndash; <a name="1">Introduction</a></h1>
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122
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123 <p>Luan is a high level programming language based on <a href="http://www.lua.org">Lua</a>. A great strength of Lua is its simplicity and Luan takes this even further, being even simpler than Lua. The goal is to provide a simple programming language for the casual programmer with as few concepts as possible so that programmers can quickly learn the language and then easily understand any code written in Luan.
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124
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125 <p>Luan is implemented in Java and is tightly coupled with Java. So it makes a great scripting language for Java programmers. By importing the <em>Java</em> package, one can directly call Java from Luan.
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126
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127 <p>Unlike Lua which is meant to be embedded, Luan is meant to be a full scripting language. This done not by adding feature to Luan, but rather by providing a complete set of libraries.
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128
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129 <h1>2 &ndash; <a name="2">Basic Concepts</a></h1>
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130
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131 <p>
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132 This section describes the basic concepts of the language.
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133
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134
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135
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136 <h2>2.1 &ndash; <a name="2.1">Values and Types</a></h2>
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137
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138 <p>
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139 Luan is a <em>dynamically typed language</em>.
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140 This means that
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141 variables do not have types; only values do.
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142 There are no type definitions in the language.
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143 All values carry their own type.
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144
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145
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146 <p>
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147 All values in Luan are <em>first-class values</em>.
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148 This means that all values can be stored in variables,
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149 passed as arguments to other functions, and returned as results.
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150
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151
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152 <p>
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153 There are eight basic types in Lua:
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154 <em>nil</em>, <em>boolean</em>, <em>number</em>,
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155 <em>string</em>, <em>binary</em>, <em>function</em>, <em>userdata</em>,
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156 and <em>table</em>.
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157 <em>Nil</em> is the type of the value <b>nil</b>,
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158 whose main property is to be different from any other value;
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159 it usually represents the absence of a useful value.
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160 <em>Nil</em> is implemented as the Java value <em>null</em>.
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161 <em>Boolean</em> is the type of the values <b>false</b> and <b>true</b>.
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162 <em>Boolean</em> is implemented as the Java class <em>Boolean</em>.
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163 <em>Number</em> represents real (double-precision floating-point) numbers.
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164 <em>Number</em> is implemented as the Java class <em>Number</em>. Any Java subclass of <em>Number</em> is allowed and this is invisible to the Luan user. Operations on numbers follow the same rules of
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165 the underlying Java&nbsp;implementation.
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166
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167 <em>String</em> is implemented as the Java class <em>String</em>.
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168 <em>Binary</em> is implemented as the Java type <em>byte[]</em>.
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169
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170
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171 <p>
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172 Luan can call (and manipulate) functions written in Luan and
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173 functions written in Java
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174 (see <a href="#3.4.9">&sect;3.4.9</a>).
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175
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176
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177 <p>
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178 The type <em>userdata</em> is provided to allow arbitrary Java&nbsp;objects to
239
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179 be stored in Lua variables.
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180 A userdata value is a Java object that isn't of the standard Luan types.
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181
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182
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183 <p>
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184 Lua has a type <em>thread</em> that Luan lacks because Luan does not have the Lua concept of coroutines.
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185
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186
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187 <p>
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188 The type <em>table</em> implements associative arrays,
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189 that is, arrays that can be indexed not only with numbers,
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190 but with any Lua value except <b>nil</b>.
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191 Tables can be <em>heterogeneous</em>;
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192 that is, they can contain values of all types (except <b>nil</b>).
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193 Any key with value <b>nil</b> is not considered part of the table.
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194 Conversely, any key that is not part of a table has
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195 an associated value <b>nil</b>.
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196
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197
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198 <p>
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199 Tables are the sole data structuring mechanism in Lua;
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200 they can be used to represent ordinary arrays, sequences,
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201 symbol tables, sets, records, graphs, trees, etc.
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202 To represent records, Lua uses the field name as an index.
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203 The language supports this representation by
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204 providing <code>a.name</code> as syntactic sugar for <code>a["name"]</code>.
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205 There are several convenient ways to create tables in Lua
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206 (see <a href="#3.4.8">&sect;3.4.8</a>).
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207
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208
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209 <p>
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210 We use the term <em>sequence</em> to denote a table where
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211 the set of all positive numeric keys is equal to <em>{1..n}</em>
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212 for some integer <em>n</em>,
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213 which is called the length of the sequence (see <a href="#3.4.6">&sect;3.4.6</a>).
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214
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215
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216 <p>
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217 Like indices,
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218 the values of table fields can be of any type.
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219 In particular,
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220 because functions are first-class values,
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221 table fields can contain functions.
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222 Thus tables can also carry <em>methods</em> (see <a href="#3.4.10">&sect;3.4.10</a>).
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223
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224
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225 <p>
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226 The indexing of tables follows
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227 the definition of raw equality in the language.
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228 The expressions <code>a[i]</code> and <code>a[j]</code>
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229 denote the same table element
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230 if and only if <code>i</code> and <code>j</code> are raw equal
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231 (that is, equal without metamethods).
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232
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233
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234 <p>
243
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235 Tables, functions, and userdata values are <em>objects</em>:
239
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236 variables do not actually <em>contain</em> these values,
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237 only <em>references</em> to them.
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238 Assignment, parameter passing, and function returns
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239 always manipulate references to such values;
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240 these operations do not imply any kind of copy.
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241
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242
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243 <p>
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244 The library function <a href="#pdf-type"><code>type</code></a> returns a string describing the type
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245 of a given value (see <a href="#6.1">&sect;6.1</a>).
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246
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247
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248
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249
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250
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251 <h2>2.2 &ndash; <a name="2.2">Environments and the Global Environment</a></h2>
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252
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253 <p>
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254 As will be discussed in <a href="#3.2">&sect;3.2</a> and <a href="#3.3.3">&sect;3.3.3</a>,
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255 any reference to a global name <code>var</code> is syntactically translated
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256 to <code>_ENV.var</code>.
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257 Moreover, every chunk is compiled in the scope of
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258 an external local variable called <code>_ENV</code> (see <a href="#3.3.2">&sect;3.3.2</a>),
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259 so <code>_ENV</code> itself is never a global name in a chunk.
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260
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261
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262 <p>
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263 Despite the existence of this external <code>_ENV</code> variable and
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264 the translation of global names,
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265 <code>_ENV</code> is a completely regular name.
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266 In particular,
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267 you can define new variables and parameters with that name.
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268 Each reference to a global name uses the <code>_ENV</code> that is
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269 visible at that point in the program,
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270 following the usual visibility rules of Lua (see <a href="#3.5">&sect;3.5</a>).
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271
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272
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273 <p>
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274 Any table used as the value of <code>_ENV</code> is called an <em>environment</em>.
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275
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276
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277 <p>
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278 Lua keeps a distinguished environment called the <em>global environment</em>.
243
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279 This value is kept in the Luan state implemented in Java.
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280 In Luan, the variable <a href="#pdf-_G"><code>_G</code></a> is initialized with this same value.
239
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281
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282
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283 <p>
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284 When Lua compiles a chunk,
243
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285 it initializes the value of its <code>_ENV</code> to an empty table.
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286 The values in the global environment become local variables of the chunk.
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287 All standard libraries are loaded in the global environment
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288 and so they become available as local variables.
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289 You can use <a href="#pdf-load"><code>load</code></a> (or <a href="#pdf-loadfile"><code>load_file</code></a>)
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290 to load a chunk with a specific environment instead of starting empty.
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291
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292
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293 <p>
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294 If you change the values in the global environment,
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295 all chunks loaded after the change will get the new environment.
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296 Previously loaded chunks are not affected, however,
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297 as each has its own references to the values in its local variables.
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298 Moreover, the variable <a href="#pdf-_G"><code>_G</code></a>
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299 (which is stored in the original global environment)
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300 is never updated by Lua.
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305
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306 <h2>2.3 &ndash; <a name="2.3">Error Handling</a></h2>
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307
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308 <p>
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309 Luan error handling is quite different from Lua.
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310
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311
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312 <p>
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313 Luan code can explicitly generate an error by calling the
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314 <a href="#pdf-error"><code>error</code></a> function.
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315 Unlike Lua, Luan has <code>try-catch</code> blocks for catching errors. This means that there is no need for Lua's <code>pcall</code> and <code>xpcall</code> functions.
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316
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317
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318 <p>
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319 Whenever there is an error,
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320 an <em>error object</em> (also called an <em>error message</em>)
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321 is propagated with information about the error.
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322 Lua itself only generates errors where the error object is a string,
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323 but programs may generate errors with
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324 any value for the error object.
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325
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326
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327
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328
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329 <h2>2.4 &ndash; <a name="2.4">Metatables and Metamethods</a></h2>
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330
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331 <p>
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332 Every table in Luan can have a <em>metatable</em>.
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333 This <em>metatable</em> is an ordinary Luan table
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334 that defines the behavior of the original table
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335 under certain special operations.
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336 You can change several aspects of the behavior
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337 of operations over a table by setting specific fields in its metatable.
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338 For instance, when a table is the operand of an addition,
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339 Luan checks for a function in the field "<code>__add</code>" of the table's metatable.
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340 If it finds one,
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341 Luan calls this function to perform the addition.
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342
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343 <p>
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344 Inside Luan's implementation, there is a global metatable that applies to all objects. This metatable is not exposed to Luan users but can be used to change the behavior of objects other than tables.
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345
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346 <p>
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347 The keys in a metatable are derived from the <em>event</em> names;
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348 the corresponding values are called <em>metamethods</em>.
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349 In the previous example, the event is <code>"add"</code>
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350 and the metamethod is the function that performs the addition.
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351
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352
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353 <p>
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354 You can query the metatable of any value
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355 using the <a href="#pdf-getmetatable"><code>get_metatable</code></a> function.
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356
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357
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358 <p>
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359 You can replace the metatable of tables
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360 using the <a href="#pdf-setmetatable"><code>set_metatable</code></a> function.
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361
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362
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363 <p>
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364 Tables have individual metatables
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365 (although multiple tables can share their metatables).
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366 By default, a table has no metatable.
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367
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368
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369 <p>
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370 A metatable controls how a table behaves in arithmetic operations,
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371 order comparisons, concatenation, length operation, and indexing.
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372 When Luan performs one of these operations over a table,
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373 it checks whether this table has a metatable with the corresponding event.
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374 If so, the value associated with that key (the metamethod)
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375 controls how Luan will perform the operation.
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376
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377
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378 <p>
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379 Metatables control the operations listed next.
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380 Each operation is identified by its corresponding name.
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381 The key for each operation is a string with its name prefixed by
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382 two underscores, '<code>__</code>';
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383 for instance, the key for operation "add" is the
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384 string "<code>__add</code>".
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387 <p>
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388 The semantics of these operations is better explained by a Luan function
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389 describing how the interpreter executes the operation.
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390 The code shown here in Lua is only illustrative;
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391 the real behavior is hard coded in the interpreter
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392 and it is much more efficient than this simulation.
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393 All functions used in these descriptions
243
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394 (<a href="#pdf-rawget"><code>raw_get</code></a>, <a href="#pdf-tonumber"><code>to_number</code></a>, etc.)
239
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395 are described in <a href="#6.1">&sect;6.1</a>.
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396 In particular, to retrieve the metamethod of a given object,
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397 we use the expression
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398
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399 <pre>
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400 metatable(obj)[event]
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401 </pre><p>
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402 This should be read as
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403
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404 <pre>
243
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405 raw_get(get_metatable(obj) or {}, event)
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406 </pre><p>
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407 This means that the access to a metamethod does not invoke other metamethods,
243
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408 and access to tables with no metatables does not fail
239
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409 (it simply results in <b>nil</b>).
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410
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411 <p>
239
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412
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413
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414 <ul>
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415
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416 <li><b>"add": </b>
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417 the <code>+</code> operation.
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418
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419
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420
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421 <p>
243
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422 The function <code>get_bin_handler</code> below defines how Luan chooses a handler
239
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423 for a binary operation.
243
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424 First, Luan tries the first operand.
239
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425 If its type does not define a handler for the operation,
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426 then Lua tries the second operand.
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427
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428 <pre>
243
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429 function get_bin_handler (op1, op2, event)
239
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430 return metatable(op1)[event] or metatable(op2)[event]
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431 end
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432 </pre><p>
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433 By using this function,
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434 the behavior of the <code>op1 + op2</code> is
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435
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436 <pre>
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437 function add_event (op1, op2)
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438 local o1, o2 = to_number(op1), to_number(op2)
239
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439 if o1 and o2 then -- both operands are numeric?
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440 return o1 + o2 -- '+' here is the primitive 'add'
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441 else -- at least one of the operands is not numeric
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442 local h = get_bin_handler(op1, op2, "__add")
239
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443 if h then
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444 -- call the handler with both operands
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445 return (h(op1, op2))
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446 else -- no handler available: default behavior
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447 error(&middot;&middot;&middot;)
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448 end
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449 end
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450 end
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451 </pre><p>
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452 </li>
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453
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454 <li><b>"sub": </b>
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455 the <code>-</code> operation.
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456
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457 Behavior similar to the "add" operation.
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458 </li>
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459
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460 <li><b>"mul": </b>
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461 the <code>*</code> operation.
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462
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463 Behavior similar to the "add" operation.
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464 </li>
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465
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466 <li><b>"span": </b>
239
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467 the <code>/</code> operation.
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468
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469 Behavior similar to the "add" operation.
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470 </li>
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471
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472 <li><b>"mod": </b>
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473 the <code>%</code> operation.
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474
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475 Behavior similar to the "add" operation,
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476 with the operation
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477 <code>o1 - floor(o1/o2)*o2</code> as the primitive operation.
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478 </li>
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479
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480 <li><b>"pow": </b>
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481 the <code>^</code> (exponentiation) operation.
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482
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483 Behavior similar to the "add" operation,
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484 with the function <code>pow</code> (from the C&nbsp;math library)
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485 as the primitive operation.
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486 </li>
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487
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488 <li><b>"unm": </b>
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489 the unary <code>-</code> operation.
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490
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491
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492 <pre>
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diff changeset
493 function unm_event (op)
243
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494 local o = to_number(op)
239
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495 if o then -- operand is numeric?
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496 return -o -- '-' here is the primitive 'unm'
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497 else -- the operand is not numeric.
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498 -- Try to get a handler from the operand
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499 local h = metatable(op).__unm
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500 if h then
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501 -- call the handler with the operand
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502 return (h(op))
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503 else -- no handler available: default behavior
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504 error(&middot;&middot;&middot;)
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505 end
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506 end
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507 end
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508 </pre><p>
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509 </li>
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510
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511 <li><b>"concat": </b>
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512 the <code>..</code> (concatenation) operation.
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513
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514
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515 <pre>
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516 function concat_event (op1, op2)
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517 if (type(op1) == "string" or type(op1) == "number") and
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518 (type(op2) == "string" or type(op2) == "number") then
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519 return op1 .. op2 -- primitive string concatenation
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520 else
243
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521 local h = get_bin_handler(op1, op2, "__concat")
239
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522 if h then
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523 return (h(op1, op2))
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524 else
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525 error(&middot;&middot;&middot;)
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526 end
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527 end
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528 end
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529 </pre><p>
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530 </li>
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531
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532 <li><b>"len": </b>
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533 the <code>#</code> operation.
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534
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535
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536 <pre>
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diff changeset
537 function len_event (op)
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538 if type(op) == "string" then
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539 return strlen(op) -- primitive string length
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540 else
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541 local h = metatable(op).__len
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diff changeset
542 if h then
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543 return (h(op)) -- call handler with the operand
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diff changeset
544 elseif type(op) == "table" then
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545 return #op -- primitive table length
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546 else -- no handler available: error
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547 error(&middot;&middot;&middot;)
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548 end
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549 end
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550 end
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551 </pre><p>
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552 See <a href="#3.4.6">&sect;3.4.6</a> for a description of the length of a table.
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553 </li>
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554
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555 <li><b>"eq": </b>
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parents:
diff changeset
556 the <code>==</code> operation.
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parents:
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557
243
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diff changeset
558 The function <code>get_equal_handler</code> defines how Luan chooses a metamethod
239
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diff changeset
559 for equality.
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parents:
diff changeset
560 A metamethod is selected only when both values
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parents:
diff changeset
561 being compared have the same type
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parents:
diff changeset
562 and the same metamethod for the selected operation,
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diff changeset
563 and the values are either tables or full userdata.
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diff changeset
564
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565 <pre>
243
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diff changeset
566 function get_equal_handler (op1, op2)
239
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567 if type(op1) ~= type(op2) or
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568 (type(op1) ~= "table" and type(op1) ~= "userdata") then
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parents:
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569 return nil -- different values
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570 end
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parents:
diff changeset
571 local mm1 = metatable(op1).__eq
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parents:
diff changeset
572 local mm2 = metatable(op2).__eq
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573 if mm1 == mm2 then return mm1 else return nil end
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parents:
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574 end
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parents:
diff changeset
575 </pre><p>
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parents:
diff changeset
576 The "eq" event is defined as follows:
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parents:
diff changeset
577
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parents:
diff changeset
578 <pre>
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parents:
diff changeset
579 function eq_event (op1, op2)
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diff changeset
580 if op1 == op2 then -- primitive equal?
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581 return true -- values are equal
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582 end
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583 -- try metamethod
243
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diff changeset
584 local h = get_equal_handler(op1, op2)
239
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585 if h then
243
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diff changeset
586 return to_boolean(h(op1, op2))
239
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diff changeset
587 else
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588 return false
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589 end
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590 end
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591 </pre><p>
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diff changeset
592 Note that the result is always a boolean.
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593 </li>
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parents:
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594
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parents:
diff changeset
595 <li><b>"lt": </b>
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diff changeset
596 the <code>&lt;</code> operation.
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597
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parents:
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598
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diff changeset
599 <pre>
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parents:
diff changeset
600 function lt_event (op1, op2)
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parents:
diff changeset
601 if type(op1) == "number" and type(op2) == "number" then
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parents:
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602 return op1 &lt; op2 -- numeric comparison
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parents:
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603 elseif type(op1) == "string" and type(op2) == "string" then
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parents:
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604 return op1 &lt; op2 -- lexicographic comparison
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605 else
243
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606 local h = get_bin_handler(op1, op2, "__lt")
239
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607 if h then
243
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608 return to_boolean(h(op1, op2))
239
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609 else
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parents:
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610 error(&middot;&middot;&middot;)
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611 end
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612 end
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613 end
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parents:
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614 </pre><p>
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parents:
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615 Note that the result is always a boolean.
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616 </li>
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diff changeset
617
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diff changeset
618 <li><b>"le": </b>
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parents:
diff changeset
619 the <code>&lt;=</code> operation.
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620
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diff changeset
621
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622 <pre>
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parents:
diff changeset
623 function le_event (op1, op2)
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diff changeset
624 if type(op1) == "number" and type(op2) == "number" then
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625 return op1 &lt;= op2 -- numeric comparison
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626 elseif type(op1) == "string" and type(op2) == "string" then
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627 return op1 &lt;= op2 -- lexicographic comparison
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628 else
243
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diff changeset
629 local h = get_bin_handler(op1, op2, "__le")
239
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630 if h then
243
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631 return to_boolean(h(op1, op2))
239
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632 else
243
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diff changeset
633 h = get_bin_handler(op1, op2, "__lt")
239
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634 if h then
243
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635 return not to_boolean(h(op2, op1))
239
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636 else
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diff changeset
637 error(&middot;&middot;&middot;)
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638 end
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639 end
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640 end
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641 end
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diff changeset
642 </pre><p>
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diff changeset
643 Note that, in the absence of a "le" metamethod,
243
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diff changeset
644 Luan tries the "lt", assuming that <code>a &lt;= b</code> is
239
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diff changeset
645 equivalent to <code>not (b &lt; a)</code>.
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646
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diff changeset
647
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parents:
diff changeset
648 <p>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
649 As with the other comparison operators,
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diff changeset
650 the result is always a boolean.
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diff changeset
651 </li>
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652
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parents:
diff changeset
653 <li><b>"index": </b>
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654 The indexing access <code>table[key]</code>.
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diff changeset
655 Note that the metamethod is tried only
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656 when <code>key</code> is not present in <code>table</code>.
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parents:
diff changeset
657 (When <code>table</code> is not a table,
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658 no key is ever present,
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diff changeset
659 so the metamethod is always tried.)
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660
aa7bc9c1df22 add unedited Lua manual
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661
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662 <pre>
243
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diff changeset
663 function get_table_event (table, key)
239
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diff changeset
664 local h
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665 if type(table) == "table" then
243
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666 local v = raw_get(table, key)
239
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667 -- if key is present, return raw value
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668 if v ~= nil then return v end
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diff changeset
669 h = metatable(table).__index
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670 if h == nil then return nil end
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671 else
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parents:
diff changeset
672 h = metatable(table).__index
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673 if h == nil then
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674 error(&middot;&middot;&middot;)
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675 end
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676 end
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677 if type(h) == "function" then
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678 return (h(table, key)) -- call the handler
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679 else return h[key] -- or repeat operation on it
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680 end
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681 end
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682 </pre><p>
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683 </li>
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parents:
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684
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
685 <li><b>"newindex": </b>
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686 The indexing assignment <code>table[key] = value</code>.
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diff changeset
687 Note that the metamethod is tried only
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688 when <code>key</code> is not present in <code>table</code>.
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689
aa7bc9c1df22 add unedited Lua manual
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diff changeset
690
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691 <pre>
243
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diff changeset
692 function set_table_event (table, key, value)
239
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693 local h
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694 if type(table) == "table" then
243
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695 local v = raw_get(table, key)
239
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696 -- if key is present, do raw assignment
243
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diff changeset
697 if v ~= nil then raw_set(table, key, value); return end
239
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698 h = metatable(table).__newindex
243
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699 if h == nil then raw_set(table, key, value); return end
239
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700 else
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701 h = metatable(table).__newindex
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702 if h == nil then
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703 error(&middot;&middot;&middot;)
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704 end
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705 end
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706 if type(h) == "function" then
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707 h(table, key,value) -- call the handler
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708 else h[key] = value -- or repeat operation on it
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709 end
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710 end
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711 </pre><p>
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712 </li>
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713
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714 <li><b>"call": </b>
243
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diff changeset
715 called when Luan calls a value.
239
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716
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717
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718 <pre>
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719 function function_event (func, ...)
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720 if type(func) == "function" then
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721 return func(...) -- primitive call
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722 else
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723 local h = metatable(func).__call
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724 if h then
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725 return h(func, ...)
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726 else
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727 error(&middot;&middot;&middot;)
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728 end
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729 end
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730 end
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731 </pre><p>
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732 </li>
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733
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734 </ul>
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735
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736
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737
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738
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739 <h2>2.5 &ndash; <a name="2.5">Garbage Collection</a></h2>
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740
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741 <p>
243
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742 Luan uses Java's garbage collection, so there is very little to say on this subject. So this section is just a place holder to replace the long explanation of Lua's garbage collection which isn't needed by Luan.
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743
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744 <p>
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diff changeset
745 Lua has <em>weak tables</em> which is a good concept but is not yet implemented in Luan. It will be added when there is a need.
239
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746
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747
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748
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749 <h2>2.6 &ndash; <a name="2.6">Coroutines</a></h2>
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750
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751 <p>
243
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752 Unlike Lua, Luan does not support coroutines. Yes coroutines are cool, but they are not simple, so in the name of simplicity, Luan does without them.
239
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753
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754
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755
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756
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757
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758 <h1>3 &ndash; <a name="3">The Language</a></h1>
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759
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760 <p>
243
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diff changeset
761 This section describes the lexis, the syntax, and the semantics of Luan.
239
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762 In other words,
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763 this section describes
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764 which tokens are valid,
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765 how they can be combined,
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766 and what their combinations mean.
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767
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768
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769 <p>
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770 Language constructs will be explained using the usual extended BNF notation,
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771 in which
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772 {<em>a</em>}&nbsp;means&nbsp;0 or more <em>a</em>'s, and
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773 [<em>a</em>]&nbsp;means an optional <em>a</em>.
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774 Non-terminals are shown like non-terminal,
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775 keywords are shown like <b>kword</b>,
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776 and other terminal symbols are shown like &lsquo;<b>=</b>&rsquo;.
243
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diff changeset
777 The complete syntax of Luan can be found in <a href="#9">&sect;9</a>
239
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778 at the end of this manual.
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779
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780
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781
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782 <h2>3.1 &ndash; <a name="3.1">Lexical Conventions</a></h2>
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783
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784 <p>
243
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diff changeset
785 Luan ignores spaces and comments
239
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786 between lexical elements (tokens),
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787 except as delimiters between names and keywords.
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788
243
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diff changeset
789 But unlike Lua, Luan generally treats the newline character as a statement separator. This is how most languages work. If a newline is preceded by a backslash, then it is treated like a space. Also, inside of parenthesis (...), brackets [...], and braces {...}, a newline is treated like a space. This allows the Luan parser to catch mistakes more easily.
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diff changeset
790
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791 <p>
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diff changeset
792 In interactive mode, Luan allows an expression on a line which is then evaluated and printed. This means that entering <em>1+1</em> on an interactive line will produce <em>2</em>.
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diff changeset
793
239
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794
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795 <p>
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796 <em>Names</em>
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797 (also called <em>identifiers</em>)
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798 in Lua can be any string of letters,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
799 digits, and underscores,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
800 not beginning with a digit.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
801 Identifiers are used to name variables, table fields, and labels.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
802
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
803
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
804 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
805 The following <em>keywords</em> are reserved
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
806 and cannot be used as names:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
807
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
808
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
809 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
810 and break do else elseif end
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
811 false for function goto if in
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
812 local nil not or repeat return
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
813 then true until while
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
814 </pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
815
243
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
816 The following <em>keywords</em> are also reserved in Luan but not in Lua:
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
817
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
818 <pre>
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
819 catch import try
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
820 </pre>
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
821
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
822
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
823
239
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
824 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
825 Lua is a case-sensitive language:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
826 <code>and</code> is a reserved word, but <code>And</code> and <code>AND</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
827 are two different, valid names.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
828 As a convention, names starting with an underscore followed by
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
829 uppercase letters (such as <a href="#pdf-_VERSION"><code>_VERSION</code></a>)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
830 are reserved for variables used by Lua.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
831
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
832
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
833 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
834 The following strings denote other tokens:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
835
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
836 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
837 + - * / % ^ #
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
838 == ~= &lt;= &gt;= &lt; &gt; =
243
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
839 ( ) { } [ ]
239
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
840 ; : , . .. ...
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
841 </pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
842
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
843 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
844 <em>Literal strings</em>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
845 can be delimited by matching single or double quotes,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
846 and can contain the following C-like escape sequences:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
847 '<code>\a</code>' (bell),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
848 '<code>\b</code>' (backspace),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
849 '<code>\f</code>' (form feed),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
850 '<code>\n</code>' (newline),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
851 '<code>\r</code>' (carriage return),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
852 '<code>\t</code>' (horizontal tab),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
853 '<code>\v</code>' (vertical tab),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
854 '<code>\\</code>' (backslash),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
855 '<code>\"</code>' (quotation mark [double quote]),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
856 and '<code>\'</code>' (apostrophe [single quote]).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
857 A backslash followed by a real newline
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
858 results in a newline in the string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
859 The escape sequence '<code>\z</code>' skips the following span
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
860 of white-space characters,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
861 including line breaks;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
862 it is particularly useful to break and indent a long literal string
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
863 into multiple lines without adding the newlines and spaces
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
864 into the string contents.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
865
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
866
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
867 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
868 A byte in a literal string can also be specified by its numerical value.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
869 This can be done with the escape sequence <code>\x<em>XX</em></code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
870 where <em>XX</em> is a sequence of exactly two hexadecimal digits,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
871 or with the escape sequence <code>\<em>ddd</em></code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
872 where <em>ddd</em> is a sequence of up to three decimal digits.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
873 (Note that if a decimal escape is to be followed by a digit,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
874 it must be expressed using exactly three digits.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
875 Strings in Lua can contain any 8-bit value, including embedded zeros,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
876 which can be specified as '<code>\0</code>'.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
877
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
878
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
879 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
880 Literal strings can also be defined using a long format
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
881 enclosed by <em>long brackets</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
882 We define an <em>opening long bracket of level <em>n</em></em> as an opening
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
883 square bracket followed by <em>n</em> equal signs followed by another
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
884 opening square bracket.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
885 So, an opening long bracket of level&nbsp;0 is written as <code>[[</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
886 an opening long bracket of level&nbsp;1 is written as <code>[=[</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
887 and so on.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
888 A <em>closing long bracket</em> is defined similarly;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
889 for instance, a closing long bracket of level&nbsp;4 is written as <code>]====]</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
890 A <em>long literal</em> starts with an opening long bracket of any level and
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
891 ends at the first closing long bracket of the same level.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
892 It can contain any text except a closing bracket of the proper level.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
893 Literals in this bracketed form can run for several lines,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
894 do not interpret any escape sequences,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
895 and ignore long brackets of any other level.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
896 Any kind of end-of-line sequence
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
897 (carriage return, newline, carriage return followed by newline,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
898 or newline followed by carriage return)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
899 is converted to a simple newline.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
900
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
901
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
902
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
903 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
904 For convenience,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
905 when the opening long bracket is immediately followed by a newline,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
906 the newline is not included in the string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
907 As an example, in a system using ASCII
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
908 (in which '<code>a</code>' is coded as&nbsp;97,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
909 newline is coded as&nbsp;10, and '<code>1</code>' is coded as&nbsp;49),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
910 the five literal strings below denote the same string:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
911
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
912 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
913 a = 'alo\n123"'
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
914 a = "alo\n123\""
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
915 a = '\97lo\10\04923"'
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
916 a = [[alo
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
917 123"]]
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
918 a = [==[
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
919 alo
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
920 123"]==]
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
921 </pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
922
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
923 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
924 A <em>numerical constant</em> can be written with an optional fractional part
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
925 and an optional decimal exponent,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
926 marked by a letter '<code>e</code>' or '<code>E</code>'.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
927 Lua also accepts hexadecimal constants,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
928 which start with <code>0x</code> or <code>0X</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
929 Hexadecimal constants also accept an optional fractional part
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
930 plus an optional binary exponent,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
931 marked by a letter '<code>p</code>' or '<code>P</code>'.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
932 Examples of valid numerical constants are
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
933
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
934 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
935 3 3.0 3.1416 314.16e-2 0.31416E1
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
936 0xff 0x0.1E 0xA23p-4 0X1.921FB54442D18P+1
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
937 </pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
938
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
939 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
940 A <em>comment</em> starts with a double hyphen (<code>--</code>)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
941 anywhere outside a string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
942 If the text immediately after <code>--</code> is not an opening long bracket,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
943 the comment is a <em>short comment</em>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
944 which runs until the end of the line.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
945 Otherwise, it is a <em>long comment</em>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
946 which runs until the corresponding closing long bracket.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
947 Long comments are frequently used to disable code temporarily.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
948
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
949
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
950
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
951
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
952
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
953 <h2>3.2 &ndash; <a name="3.2">Variables</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
954
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
955 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
956 Variables are places that store values.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
957 There are three kinds of variables in Lua:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
958 global variables, local variables, and table fields.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
959
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
960
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
961 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
962 A single name can denote a global variable or a local variable
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
963 (or a function's formal parameter,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
964 which is a particular kind of local variable):
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
965
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
966 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
967 var ::= Name
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
968 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
969 Name denotes identifiers, as defined in <a href="#3.1">&sect;3.1</a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
970
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
971
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
972 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
973 Any variable name is assumed to be global unless explicitly declared
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
974 as a local (see <a href="#3.3.7">&sect;3.3.7</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
975 Local variables are <em>lexically scoped</em>:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
976 local variables can be freely accessed by functions
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
977 defined inside their scope (see <a href="#3.5">&sect;3.5</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
978
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
979
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
980 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
981 Before the first assignment to a variable, its value is <b>nil</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
982
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
983
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
984 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
985 Square brackets are used to index a table:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
986
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
987 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
988 var ::= prefixexp &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
989 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
990 The meaning of accesses to table fields can be changed via metatables.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
991 An access to an indexed variable <code>t[i]</code> is equivalent to
243
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
992 a call <code>get_table_event(t,i)</code>.
239
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
993 (See <a href="#2.4">&sect;2.4</a> for a complete description of the
243
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
994 <code>get_table_event</code> function.
239
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
995 This function is not defined or callable in Lua.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
996 We use it here only for explanatory purposes.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
997
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
998
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
999 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1000 The syntax <code>var.Name</code> is just syntactic sugar for
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1001 <code>var["Name"]</code>:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1002
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1003 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1004 var ::= prefixexp &lsquo;<b>.</b>&rsquo; Name
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1005 </pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1006
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1007 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1008 An access to a global variable <code>x</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1009 is equivalent to <code>_ENV.x</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1010 Due to the way that chunks are compiled,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1011 <code>_ENV</code> is never a global name (see <a href="#2.2">&sect;2.2</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1012
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1013
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1014
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1015
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1016
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1017 <h2>3.3 &ndash; <a name="3.3">Statements</a></h2>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1018
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1019 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1020 Lua supports an almost conventional set of statements,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1021 similar to those in Pascal or C.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1022 This set includes
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1023 assignments, control structures, function calls,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1024 and variable declarations.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1025
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1026
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1027
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1028 <h3>3.3.1 &ndash; <a name="3.3.1">Blocks</a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1029
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1030 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1031 A block is a list of statements,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1032 which are executed sequentially:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1033
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1034 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1035 block ::= {stat}
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1036 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1037 Lua has <em>empty statements</em>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1038 that allow you to separate statements with semicolons,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1039 start a block with a semicolon
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1040 or write two semicolons in sequence:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1041
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1042 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1043 stat ::= &lsquo;<b>;</b>&rsquo;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1044 </pre>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1045
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parents:
diff changeset
1046
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1047 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1048 A block can be explicitly delimited to produce a single statement:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1049
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1050 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1051 stat ::= <b>do</b> block <b>end</b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1052 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1053 Explicit blocks are useful
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1054 to control the scope of variable declarations.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1055
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parents:
diff changeset
1056
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parents:
diff changeset
1057
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1058
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1059
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1060 <h3>3.3.2 &ndash; <a name="3.3.2">Chunks</a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1061
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1062 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1063 The unit of compilation of Lua is called a <em>chunk</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1064 Syntactically,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1065 a chunk is simply a block:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1066
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1067 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1068 chunk ::= block
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1069 </pre>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1070
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1071 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1072 Lua handles a chunk as the body of an anonymous function
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1073 with a variable number of arguments
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1074 (see <a href="#3.4.10">&sect;3.4.10</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1075 As such, chunks can define local variables,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1076 receive arguments, and return values.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1077 Moreover, such anonymous function is compiled as in the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1078 scope of an external local variable called <code>_ENV</code> (see <a href="#2.2">&sect;2.2</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1079 The resulting function always has <code>_ENV</code> as its only upvalue,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1080 even if it does not use that variable.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1081
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1082
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1083 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1084 A chunk can be stored in a file or in a string inside the host program.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1085 To execute a chunk,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1086 Lua first precompiles the chunk into instructions for a virtual machine,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1087 and then it executes the compiled code
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1088 with an interpreter for the virtual machine.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1089
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1090
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1091
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1092
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1093
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1094
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1095 <h3>3.3.3 &ndash; <a name="3.3.3">Assignment</a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1096
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1097 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1098 Lua allows multiple assignments.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1099 Therefore, the syntax for assignment
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1100 defines a list of variables on the left side
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1101 and a list of expressions on the right side.
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1102 The elements in both lists are separated by commas:
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1103
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parents:
diff changeset
1104 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1105 stat ::= varlist &lsquo;<b>=</b>&rsquo; explist
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1106 varlist ::= var {&lsquo;<b>,</b>&rsquo; var}
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1107 explist ::= exp {&lsquo;<b>,</b>&rsquo; exp}
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1108 </pre><p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1109 Expressions are discussed in <a href="#3.4">&sect;3.4</a>.
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parents:
diff changeset
1110
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parents:
diff changeset
1111
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1112 <p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1113 Before the assignment,
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1114 the list of values is <em>adjusted</em> to the length of
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1115 the list of variables.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1116 If there are more values than needed,
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1117 the excess values are thrown away.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1118 If there are fewer values than needed,
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1119 the list is extended with as many <b>nil</b>'s as needed.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1120 If the list of expressions ends with a function call,
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1121 then all values returned by that call enter the list of values,
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1122 before the adjustment
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parents:
diff changeset
1123 (except when the call is enclosed in parentheses; see <a href="#3.4">&sect;3.4</a>).
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parents:
diff changeset
1124
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parents:
diff changeset
1125
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parents:
diff changeset
1126 <p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1127 The assignment statement first evaluates all its expressions
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1128 and only then are the assignments performed.
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parents:
diff changeset
1129 Thus the code
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parents:
diff changeset
1130
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parents:
diff changeset
1131 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1132 i = 3
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1133 i, a[i] = i+1, 20
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1134 </pre><p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1135 sets <code>a[3]</code> to 20, without affecting <code>a[4]</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1136 because the <code>i</code> in <code>a[i]</code> is evaluated (to 3)
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1137 before it is assigned&nbsp;4.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1138 Similarly, the line
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parents:
diff changeset
1139
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parents:
diff changeset
1140 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1141 x, y = y, x
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1142 </pre><p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1143 exchanges the values of <code>x</code> and <code>y</code>,
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1144 and
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parents:
diff changeset
1145
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parents:
diff changeset
1146 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1147 x, y, z = y, z, x
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1148 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1149 cyclically permutes the values of <code>x</code>, <code>y</code>, and <code>z</code>.
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parents:
diff changeset
1150
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parents:
diff changeset
1151
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parents:
diff changeset
1152 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1153 The meaning of assignments to global variables
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1154 and table fields can be changed via metatables.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1155 An assignment to an indexed variable <code>t[i] = val</code> is equivalent to
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1156 <code>settable_event(t,i,val)</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1157 (See <a href="#2.4">&sect;2.4</a> for a complete description of the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1158 <code>settable_event</code> function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1159 This function is not defined or callable in Lua.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1160 We use it here only for explanatory purposes.)
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parents:
diff changeset
1161
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parents:
diff changeset
1162
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diff changeset
1163 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1164 An assignment to a global variable <code>x = val</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1165 is equivalent to the assignment
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1166 <code>_ENV.x = val</code> (see <a href="#2.2">&sect;2.2</a>).
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parents:
diff changeset
1167
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parents:
diff changeset
1168
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parents:
diff changeset
1169
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parents:
diff changeset
1170
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parents:
diff changeset
1171
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1172 <h3>3.3.4 &ndash; <a name="3.3.4">Control Structures</a></h3><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1173 The control structures
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1174 <b>if</b>, <b>while</b>, and <b>repeat</b> have the usual meaning and
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1175 familiar syntax:
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parents:
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1176
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parents:
diff changeset
1177
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parents:
diff changeset
1178
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parents:
diff changeset
1179
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parents:
diff changeset
1180 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1181 stat ::= <b>while</b> exp <b>do</b> block <b>end</b>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1182 stat ::= <b>repeat</b> block <b>until</b> exp
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1183 stat ::= <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] <b>end</b>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1184 </pre><p>
243
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parents: 242
diff changeset
1185 Lua also has a <b>for</b> statement (see <a href="#3.3.5">&sect;3.3.5</a>).
239
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diff changeset
1186
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parents:
diff changeset
1187
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diff changeset
1188 <p>
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parents:
diff changeset
1189 The condition expression of a
243
c912f6de2053 more work on the manual
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parents: 242
diff changeset
1190 control structure must return a boolean.
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parents: 242
diff changeset
1191 This is unlike Lua and is intended to catch programming errors more quickly.
239
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1192
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parents:
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1193
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1194 <p>
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parents:
diff changeset
1195 In the <b>repeat</b>&ndash;<b>until</b> loop,
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parents:
diff changeset
1196 the inner block does not end at the <b>until</b> keyword,
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parents:
diff changeset
1197 but only after the condition.
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parents:
diff changeset
1198 So, the condition can refer to local variables
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parents:
diff changeset
1199 declared inside the loop block.
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parents:
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1200
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1201
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1202
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1203
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1204 <p>
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parents:
diff changeset
1205 The <b>break</b> statement terminates the execution of a
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parents:
diff changeset
1206 <b>while</b>, <b>repeat</b>, or <b>for</b> loop,
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
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1207 skipping to the next statement after the loop:
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1208
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1209
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diff changeset
1210 <pre>
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diff changeset
1211 stat ::= <b>break</b>
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1212 </pre><p>
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diff changeset
1213 A <b>break</b> ends the innermost enclosing loop.
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1214
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1215
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1216 <p>
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diff changeset
1217 The <b>return</b> statement is used to return values
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parents:
diff changeset
1218 from a function or a chunk (which is a function in disguise).
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1219
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diff changeset
1220 Functions can return more than one value,
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1221 so the syntax for the <b>return</b> statement is
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1222
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1223 <pre>
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1224 stat ::= <b>return</b> [explist] [&lsquo;<b>;</b>&rsquo;]
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1225 </pre>
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1226
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1227
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1228
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1229
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1230
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diff changeset
1231 <h3>3.3.5 &ndash; <a name="3.3.5">For Statement</a></h3>
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1232
243
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1233
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1234 <p>
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diff changeset
1235 The <b>for</b> statement works over functions,
239
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1236 called <em>iterators</em>.
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1237 On each iteration, the iterator function is called to produce a new value,
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1238 stopping when this new value is <b>nil</b>.
243
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1239 The <b>for</b> loop has the following syntax:
239
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1240
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1241 <pre>
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diff changeset
1242 stat ::= <b>for</b> namelist <b>in</b> explist <b>do</b> block <b>end</b>
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1243 namelist ::= Name {&lsquo;<b>,</b>&rsquo; Name}
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1244 </pre><p>
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1245 A <b>for</b> statement like
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1246
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1247 <pre>
243
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1248 for <em>var_1</em>, &middot;&middot;&middot;, <em>var_n</em> in <em>expression</em> do <em>block</em> end
239
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1249 </pre><p>
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diff changeset
1250 is equivalent to the code:
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1251
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1252 <pre>
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1253 do
243
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1254 local <em>f</em> = <em>expression</em>
239
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1255 while true do
243
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diff changeset
1256 local <em>var_1</em>, &middot;&middot;&middot;, <em>var_n</em> = <em>f</em>()
239
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1257 if <em>var_1</em> == nil then break end
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1258 <em>block</em>
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1259 end
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1260 end
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1261 </pre><p>
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1262 Note the following:
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1263
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1264 <ul>
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1265
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1266 <li>
243
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1267 <code><em>expression</em></code> is evaluated only once.
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1268 Its result is an <em>iterator</em> function.
239
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1269 </li>
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1270
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1271 <li>
243
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diff changeset
1272 <code><em>f</em></code> is an invisible variable.
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diff changeset
1273 The name is here for explanatory purposes only.
239
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1274 </li>
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1275
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1276 <li>
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diff changeset
1277 You can use <b>break</b> to exit a <b>for</b> loop.
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1278 </li>
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1279
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1280 <li>
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1281 The loop variables <code><em>var_i</em></code> are local to the loop;
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1282 you cannot use their values after the <b>for</b> ends.
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1283 If you need these values,
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1284 then assign them to other variables before breaking or exiting the loop.
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1285 </li>
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1286
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1287 </ul>
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1288
243
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1289 <p>
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diff changeset
1290 Lua also has a numeric <b>for</b> statement which Luan does not support. Instead, Luan offers the <em>range</em> function (inspired by Python) which does the same thing without adding to the syntax of the language.
239
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1291
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1292
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diff changeset
1293 <h3>3.3.6 &ndash; <a name="3.3.6">Function Calls as Statements</a></h3><p>
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diff changeset
1294 To allow possible side-effects,
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1295 function calls can be executed as statements:
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1296
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1297 <pre>
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1298 stat ::= functioncall
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1299 </pre><p>
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1300 In this case, all returned values are thrown away.
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1301 Function calls are explained in <a href="#3.4.9">&sect;3.4.9</a>.
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1302
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1303
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1304
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1305
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1306
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diff changeset
1307 <h3>3.3.7 &ndash; <a name="3.3.7">Local Declarations</a></h3><p>
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diff changeset
1308 Local variables can be declared anywhere inside a block.
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diff changeset
1309 The declaration can include an initial assignment:
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1310
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diff changeset
1311 <pre>
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parents:
diff changeset
1312 stat ::= <b>local</b> namelist [&lsquo;<b>=</b>&rsquo; explist]
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diff changeset
1313 </pre><p>
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diff changeset
1314 If present, an initial assignment has the same semantics
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diff changeset
1315 of a multiple assignment (see <a href="#3.3.3">&sect;3.3.3</a>).
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diff changeset
1316 Otherwise, all variables are initialized with <b>nil</b>.
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1317
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diff changeset
1318 <p>
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parents:
diff changeset
1319 A chunk is also a block (see <a href="#3.3.2">&sect;3.3.2</a>),
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
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diff changeset
1320 and so local variables can be declared in a chunk outside any explicit block.
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1321
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1322
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1323 <p>
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diff changeset
1324 The visibility rules for local variables are explained in <a href="#3.5">&sect;3.5</a>.
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1325
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1326
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diff changeset
1327
243
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diff changeset
1328 <h3>3.3.8 &ndash; <a name="3.3.8">Or/And Statements</a></h3><p>
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diff changeset
1329
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diff changeset
1330 <p>
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diff changeset
1331 An <b>or</b> or <b>and</b> expression is also considered a statement. This is new for Luan and doesn't exist in Lua.
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diff changeset
1332
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diff changeset
1333 <p>For example, consider a function <em>do_something</em> that returns a boolean indicating whether it succeeded or failed. You can then do:
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diff changeset
1334
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diff changeset
1335 <pre>
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diff changeset
1336 do_something() or error "didn't work"
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1337 </pre>
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diff changeset
1338
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diff changeset
1339
239
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1340
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1341
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1342
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diff changeset
1343
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diff changeset
1344 <h2>3.4 &ndash; <a name="3.4">Expressions</a></h2>
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1345
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1346 <p>
243
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diff changeset
1347 The basic expressions in Luan are the following:
239
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1348
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diff changeset
1349 <pre>
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parents:
diff changeset
1350 exp ::= prefixexp
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diff changeset
1351 exp ::= <b>nil</b> | <b>false</b> | <b>true</b>
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diff changeset
1352 exp ::= Number
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diff changeset
1353 exp ::= String
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diff changeset
1354 exp ::= functiondef
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diff changeset
1355 exp ::= tableconstructor
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parents:
diff changeset
1356 exp ::= &lsquo;<b>...</b>&rsquo;
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diff changeset
1357 exp ::= exp binop exp
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diff changeset
1358 exp ::= unop exp
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diff changeset
1359 prefixexp ::= var | functioncall | &lsquo;<b>(</b>&rsquo; exp &lsquo;<b>)</b>&rsquo;
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parents:
diff changeset
1360 </pre>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1361
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1362 <p>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1363 Numbers and literal strings are explained in <a href="#3.1">&sect;3.1</a>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1364 variables are explained in <a href="#3.2">&sect;3.2</a>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1365 function definitions are explained in <a href="#3.4.10">&sect;3.4.10</a>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1366 function calls are explained in <a href="#3.4.9">&sect;3.4.9</a>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1367 table constructors are explained in <a href="#3.4.8">&sect;3.4.8</a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1368 Vararg expressions,
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1369 denoted by three dots ('<code>...</code>'), can only be used when
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1370 directly inside a vararg function;
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parents:
diff changeset
1371 they are explained in <a href="#3.4.10">&sect;3.4.10</a>.
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diff changeset
1372
aa7bc9c1df22 add unedited Lua manual
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diff changeset
1373
aa7bc9c1df22 add unedited Lua manual
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diff changeset
1374 <p>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1375 Binary operators comprise arithmetic operators (see <a href="#3.4.1">&sect;3.4.1</a>),
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1376 relational operators (see <a href="#3.4.3">&sect;3.4.3</a>), logical operators (see <a href="#3.4.4">&sect;3.4.4</a>),
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1377 and the concatenation operator (see <a href="#3.4.5">&sect;3.4.5</a>).
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1378 Unary operators comprise the unary minus (see <a href="#3.4.1">&sect;3.4.1</a>),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1379 the unary <b>not</b> (see <a href="#3.4.4">&sect;3.4.4</a>),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1380 and the unary <em>length operator</em> (see <a href="#3.4.6">&sect;3.4.6</a>).
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diff changeset
1381
aa7bc9c1df22 add unedited Lua manual
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diff changeset
1382
aa7bc9c1df22 add unedited Lua manual
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diff changeset
1383 <p>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1384 Both function calls and vararg expressions can result in multiple values.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1385 If a function call is used as a statement (see <a href="#3.3.6">&sect;3.3.6</a>),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1386 then its return list is adjusted to zero elements,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1387 thus discarding all returned values.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1388 If an expression is used as the last (or the only) element
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1389 of a list of expressions,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1390 then no adjustment is made
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1391 (unless the expression is enclosed in parentheses).
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1392 In all other contexts,
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diff changeset
1393 Lua adjusts the result list to one element,
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diff changeset
1394 either discarding all values except the first one
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diff changeset
1395 or adding a single <b>nil</b> if there are no values.
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diff changeset
1396
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diff changeset
1397
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diff changeset
1398 <p>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1399 Here are some examples:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1400
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1401 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1402 f() -- adjusted to 0 results
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1403 g(f(), x) -- f() is adjusted to 1 result
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1404 g(x, f()) -- g gets x plus all results from f()
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1405 a,b,c = f(), x -- f() is adjusted to 1 result (c gets nil)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1406 a,b = ... -- a gets the first vararg parameter, b gets
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1407 -- the second (both a and b can get nil if there
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1408 -- is no corresponding vararg parameter)
242
b5a926c481a5 Handle first h1 tag differently.
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parents: 241
diff changeset
1409
239
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parents:
diff changeset
1410 a,b,c = x, f() -- f() is adjusted to 2 results
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1411 a,b,c = f() -- f() is adjusted to 3 results
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1412 return f() -- returns all results from f()
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1413 return ... -- returns all received vararg parameters
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1414 return x,y,f() -- returns x, y, and all results from f()
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1415 {f()} -- creates a list with all results from f()
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1416 {...} -- creates a list with all vararg parameters
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1417 {f(), nil} -- f() is adjusted to 1 result
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1418 </pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1419
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1420 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1421 Any expression enclosed in parentheses always results in only one value.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1422 Thus,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1423 <code>(f(x,y,z))</code> is always a single value,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1424 even if <code>f</code> returns several values.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1425 (The value of <code>(f(x,y,z))</code> is the first value returned by <code>f</code>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1426 or <b>nil</b> if <code>f</code> does not return any values.)
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1427
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parents:
diff changeset
1428
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parents:
diff changeset
1429
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1430 <h3>3.4.1 &ndash; <a name="3.4.1">Arithmetic Operators</a></h3><p>
243
c912f6de2053 more work on the manual
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diff changeset
1431 Luan supports the usual arithmetic operators:
239
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1432 the binary <code>+</code> (addition),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1433 <code>-</code> (subtraction), <code>*</code> (multiplication),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1434 <code>/</code> (division), <code>%</code> (modulo), and <code>^</code> (exponentiation);
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1435 and unary <code>-</code> (mathematical negation).
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1436 If the operands are numbers, or strings that can be converted to
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1437 numbers (see <a href="#3.4.2">&sect;3.4.2</a>),
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1438 then all operations have the usual meaning.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1439 Exponentiation works for any exponent.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1440 For instance, <code>x^(-0.5)</code> computes the inverse of the square root of <code>x</code>.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1441 Modulo is defined as
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1442
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1443 <pre>
243
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diff changeset
1444 a % b == a - Math.floor(a/b)*b
239
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1445 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1446 That is, it is the remainder of a division that rounds
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1447 the quotient towards minus infinity.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1448
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parents:
diff changeset
1449
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parents:
diff changeset
1450
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parents:
diff changeset
1451
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parents:
diff changeset
1452
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1453 <h3>3.4.2 &ndash; <a name="3.4.2">Coercion</a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1454
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parents:
diff changeset
1455 <p>
243
c912f6de2053 more work on the manual
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parents: 242
diff changeset
1456 Luan provides automatic conversion between
239
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1457 string and number values at run time.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1458 Any arithmetic operation applied to a string tries to convert
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1459 this string to a number, following the rules of the Lua lexer.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1460 (The string may have leading and trailing spaces and a sign.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1461 Conversely, whenever a number is used where a string is expected,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1462 the number is converted to a string, in a reasonable format.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1463 For complete control over how numbers are converted to strings,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1464 use the <code>format</code> function from the string library
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1465 (see <a href="#pdf-string.format"><code>string.format</code></a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1466
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1467
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1468
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1469
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1470
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1471 <h3>3.4.3 &ndash; <a name="3.4.3">Relational Operators</a></h3><p>
243
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
1472 The relational operators in Luan are
239
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1473
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1474 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1475 == ~= &lt; &gt; &lt;= &gt;=
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1476 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1477 These operators always result in <b>false</b> or <b>true</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1478
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parents:
diff changeset
1479
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1480 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1481 Equality (<code>==</code>) first compares the type of its operands.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1482 If the types are different, then the result is <b>false</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1483 Otherwise, the values of the operands are compared.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1484 Numbers and strings are compared in the usual way.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1485 Tables, userdata, and threads
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1486 are compared by reference:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1487 two objects are considered equal only if they are the same object.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1488 Every time you create a new object
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1489 (a table, userdata, or thread),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1490 this new object is different from any previously existing object.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1491 Closures with the same reference are always equal.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1492 Closures with any detectable difference
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1493 (different behavior, different definition) are always different.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1494
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parents:
diff changeset
1495
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parents:
diff changeset
1496 <p>
243
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diff changeset
1497 You can change the way that Luan compares tables
239
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parents:
diff changeset
1498 by using the "eq" metamethod (see <a href="#2.4">&sect;2.4</a>).
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1499
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parents:
diff changeset
1500
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1501 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1502 The conversion rules of <a href="#3.4.2">&sect;3.4.2</a>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1503 do not apply to equality comparisons.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1504 Thus, <code>"0"==0</code> evaluates to <b>false</b>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1505 and <code>t[0]</code> and <code>t["0"]</code> denote different
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1506 entries in a table.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1507
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parents:
diff changeset
1508
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1509 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1510 The operator <code>~=</code> is exactly the negation of equality (<code>==</code>).
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1511
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parents:
diff changeset
1512
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1513 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1514 The order operators work as follows.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1515 If both arguments are numbers, then they are compared as such.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1516 Otherwise, if both arguments are strings,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1517 then their values are compared according to the current locale.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1518 Otherwise, Lua tries to call the "lt" or the "le"
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1519 metamethod (see <a href="#2.4">&sect;2.4</a>).
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1520 A comparison <code>a &gt; b</code> is translated to <code>b &lt; a</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1521 and <code>a &gt;= b</code> is translated to <code>b &lt;= a</code>.
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parents:
diff changeset
1522
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parents:
diff changeset
1523
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parents:
diff changeset
1524
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parents:
diff changeset
1525
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parents:
diff changeset
1526
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1527 <h3>3.4.4 &ndash; <a name="3.4.4">Logical Operators</a></h3><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1528 The logical operators in Lua are
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1529 <b>and</b>, <b>or</b>, and <b>not</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1530 Like the control structures (see <a href="#3.3.4">&sect;3.3.4</a>),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1531 all logical operators consider both <b>false</b> and <b>nil</b> as false
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1532 and anything else as true.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1533
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parents:
diff changeset
1534
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1535 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1536 The negation operator <b>not</b> always returns <b>false</b> or <b>true</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1537 The conjunction operator <b>and</b> returns its first argument
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1538 if this value is <b>false</b> or <b>nil</b>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1539 otherwise, <b>and</b> returns its second argument.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1540 The disjunction operator <b>or</b> returns its first argument
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1541 if this value is different from <b>nil</b> and <b>false</b>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1542 otherwise, <b>or</b> returns its second argument.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1543 Both <b>and</b> and <b>or</b> use short-cut evaluation;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1544 that is,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1545 the second operand is evaluated only if necessary.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1546 Here are some examples:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1547
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1548 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1549 10 or 20 --&gt; 10
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1550 10 or error() --&gt; 10
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1551 nil or "a" --&gt; "a"
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1552 nil and 10 --&gt; nil
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1553 false and error() --&gt; false
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1554 false and nil --&gt; false
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1555 false or nil --&gt; nil
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1556 10 and 20 --&gt; 20
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1557 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1558 (In this manual,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1559 <code>--&gt;</code> indicates the result of the preceding expression.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1560
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1561
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1562
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1563
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1564
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1565 <h3>3.4.5 &ndash; <a name="3.4.5">Concatenation</a></h3><p>
243
c912f6de2053 more work on the manual
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parents: 242
diff changeset
1566 The string concatenation operator in Luan is
239
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1567 denoted by two dots ('<code>..</code>').
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1568 If both operands are strings or numbers, then they are converted to
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1569 strings according to the rules mentioned in <a href="#3.4.2">&sect;3.4.2</a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1570 Otherwise, the <code>__concat</code> metamethod is called (see <a href="#2.4">&sect;2.4</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1571
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1572
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1573
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1574
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1575
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1576 <h3>3.4.6 &ndash; <a name="3.4.6">The Length Operator</a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1577
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1578 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1579 The length operator is denoted by the unary prefix operator <code>#</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1580 The length of a string is its number of bytes
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1581 (that is, the usual meaning of string length when each
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1582 character is one byte).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1583
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1584
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1585 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1586 A program can modify the behavior of the length operator for
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1587 any value but strings through the <code>__len</code> metamethod (see <a href="#2.4">&sect;2.4</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1588
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1589
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1590 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1591 Unless a <code>__len</code> metamethod is given,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1592 the length of a table <code>t</code> is only defined if the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1593 table is a <em>sequence</em>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1594 that is,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1595 the set of its positive numeric keys is equal to <em>{1..n}</em>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1596 for some integer <em>n</em>.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1597 In that case, <em>n</em> is its length.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1598 Note that a table like
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1599
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1600 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1601 {10, 20, nil, 40}
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1602 </pre><p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1603 is not a sequence, because it has the key <code>4</code>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1604 but does not have the key <code>3</code>.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1605 (So, there is no <em>n</em> such that the set <em>{1..n}</em> is equal
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1606 to the set of positive numeric keys of that table.)
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1607 Note, however, that non-numeric keys do not interfere
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1608 with whether a table is a sequence.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1609
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1610
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parents:
diff changeset
1611
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1612
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1613
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1614 <h3>3.4.7 &ndash; <a name="3.4.7">Precedence</a></h3><p>
243
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
1615 Operator precedence in Luan follows the table below,
239
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1616 from lower to higher priority:
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
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1617
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1618 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1619 or
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1620 and
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1621 &lt; &gt; &lt;= &gt;= ~= ==
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1622 ..
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1623 + -
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1624 * / %
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1625 not # - (unary)
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1626 ^
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1627 </pre><p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1628 As usual,
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1629 you can use parentheses to change the precedences of an expression.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1630 The concatenation ('<code>..</code>') and exponentiation ('<code>^</code>')
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1631 operators are right associative.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1632 All other binary operators are left associative.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
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1633
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parents:
diff changeset
1634
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parents:
diff changeset
1635
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parents:
diff changeset
1636
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parents:
diff changeset
1637
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1638 <h3>3.4.8 &ndash; <a name="3.4.8">Table Constructors</a></h3><p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1639 Table constructors are expressions that create tables.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1640 Every time a constructor is evaluated, a new table is created.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1641 A constructor can be used to create an empty table
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1642 or to create a table and initialize some of its fields.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1643 The general syntax for constructors is
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parents:
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1644
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parents:
diff changeset
1645 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1646 tableconstructor ::= &lsquo;<b>{</b>&rsquo; [fieldlist] &lsquo;<b>}</b>&rsquo;
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1647 fieldlist ::= field {fieldsep field} [fieldsep]
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1648 field ::= &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo; &lsquo;<b>=</b>&rsquo; exp | Name &lsquo;<b>=</b>&rsquo; exp | exp
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1649 fieldsep ::= &lsquo;<b>,</b>&rsquo; | &lsquo;<b>;</b>&rsquo;
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1650 </pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1651
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parents:
diff changeset
1652 <p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1653 Each field of the form <code>[exp1] = exp2</code> adds to the new table an entry
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1654 with key <code>exp1</code> and value <code>exp2</code>.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1655 A field of the form <code>name = exp</code> is equivalent to
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1656 <code>["name"] = exp</code>.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1657 Finally, fields of the form <code>exp</code> are equivalent to
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parents:
diff changeset
1658 <code>[i] = exp</code>, where <code>i</code> are consecutive numerical integers,
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1659 starting with 1.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1660 Fields in the other formats do not affect this counting.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1661 For example,
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parents:
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1662
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1663 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1664 a = { [f(1)] = g; "x", "y"; x = 1, f(x), [30] = 23; 45 }
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1665 </pre><p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1666 is equivalent to
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
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1667
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1668 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1669 do
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1670 local t = {}
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1671 t[f(1)] = g
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1672 t[1] = "x" -- 1st exp
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1673 t[2] = "y" -- 2nd exp
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1674 t.x = 1 -- t["x"] = 1
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1675 t[3] = f(x) -- 3rd exp
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1676 t[30] = 23
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1677 t[4] = 45 -- 4th exp
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1678 a = t
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
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1679 end
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1680 </pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
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1681
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1682 <p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1683 If the last field in the list has the form <code>exp</code>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1684 and the expression is a function call or a vararg expression,
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1685 then all values returned by this expression enter the list consecutively
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1686 (see <a href="#3.4.9">&sect;3.4.9</a>).
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parents:
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1687
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parents:
diff changeset
1688
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parents:
diff changeset
1689 <p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1690 The field list can have an optional trailing separator,
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1691 as a convenience for machine-generated code.
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parents:
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1692
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parents:
diff changeset
1693
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parents:
diff changeset
1694
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diff changeset
1695
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diff changeset
1696
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parents:
diff changeset
1697 <h3>3.4.9 &ndash; <a name="3.4.9">Function Calls</a></h3><p>
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diff changeset
1698 A function call in Luan has the following syntax:
239
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diff changeset
1699
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parents:
diff changeset
1700 <pre>
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diff changeset
1701 functioncall ::= prefixexp args
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diff changeset
1702 </pre><p>
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parents:
diff changeset
1703 In a function call,
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parents:
diff changeset
1704 first prefixexp and args are evaluated.
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parents:
diff changeset
1705 If the value of prefixexp has type <em>function</em>,
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parents:
diff changeset
1706 then this function is called
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parents:
diff changeset
1707 with the given arguments.
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diff changeset
1708 Otherwise, the prefixexp "call" metamethod is called,
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parents:
diff changeset
1709 having as first parameter the value of prefixexp,
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parents:
diff changeset
1710 followed by the original call arguments
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parents:
diff changeset
1711 (see <a href="#2.4">&sect;2.4</a>).
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1712
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diff changeset
1713
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diff changeset
1714 <p>
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diff changeset
1715 Lua supports a special function call for "methods" like <em>obj:fn(args)</em> . Luan does not support this.
239
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diff changeset
1716
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diff changeset
1717 <p>
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diff changeset
1718 Arguments have the following syntax:
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1719
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diff changeset
1720 <pre>
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diff changeset
1721 args ::= &lsquo;<b>(</b>&rsquo; [explist] &lsquo;<b>)</b>&rsquo;
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1722 args ::= tableconstructor
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1723 args ::= String
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diff changeset
1724 </pre><p>
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diff changeset
1725 All argument expressions are evaluated before the call.
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parents:
diff changeset
1726 A call of the form <code>f{<em>fields</em>}</code> is
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parents:
diff changeset
1727 syntactic sugar for <code>f({<em>fields</em>})</code>;
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1728 that is, the argument list is a single new table.
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parents:
diff changeset
1729 A call of the form <code>f'<em>string</em>'</code>
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parents:
diff changeset
1730 (or <code>f"<em>string</em>"</code> or <code>f[[<em>string</em>]]</code>)
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parents:
diff changeset
1731 is syntactic sugar for <code>f('<em>string</em>')</code>;
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1732 that is, the argument list is a single literal string.
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diff changeset
1733
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diff changeset
1734
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diff changeset
1735 <p>
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parents:
diff changeset
1736 A call of the form <code>return <em>functioncall</em></code> is called
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diff changeset
1737 a <em>tail call</em>.
243
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diff changeset
1738 Luan implements <em>proper tail calls</em>
239
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diff changeset
1739 (or <em>proper tail recursion</em>):
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parents:
diff changeset
1740 in a tail call,
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parents:
diff changeset
1741 the called function reuses the stack entry of the calling function.
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parents:
diff changeset
1742 Therefore, there is no limit on the number of nested tail calls that
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parents:
diff changeset
1743 a program can execute.
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parents:
diff changeset
1744 However, a tail call erases any debug information about the
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parents:
diff changeset
1745 calling function.
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parents:
diff changeset
1746 Note that a tail call only happens with a particular syntax,
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parents:
diff changeset
1747 where the <b>return</b> has one single function call as argument;
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diff changeset
1748 this syntax makes the calling function return exactly
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diff changeset
1749 the returns of the called function.
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parents:
diff changeset
1750 So, none of the following examples are tail calls:
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diff changeset
1751
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parents:
diff changeset
1752 <pre>
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parents:
diff changeset
1753 return (f(x)) -- results adjusted to 1
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diff changeset
1754 return 2 * f(x)
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diff changeset
1755 return x, f(x) -- additional results
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diff changeset
1756 f(x); return -- results discarded
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parents:
diff changeset
1757 return x or f(x) -- results adjusted to 1
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diff changeset
1758 </pre>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1759
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diff changeset
1760
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diff changeset
1761
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diff changeset
1762
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1763 <h3>3.4.10 &ndash; <a name="3.4.10">Function Definitions</a></h3>
aa7bc9c1df22 add unedited Lua manual
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diff changeset
1764
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1765 <p>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1766 The syntax for function definition is
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diff changeset
1767
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parents:
diff changeset
1768 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1769 functiondef ::= <b>function</b> funcbody
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
1770 funcbody ::= &lsquo;<b>(</b>&rsquo; [parlist] &lsquo;<b>)</b>&rsquo; block <b>end</b>
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diff changeset
1771 </pre>
aa7bc9c1df22 add unedited Lua manual
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diff changeset
1772
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parents:
diff changeset
1773 <p>
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parents:
diff changeset
1774 The following syntactic sugar simplifies function definitions:
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parents:
diff changeset
1775
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diff changeset
1776 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1777 stat ::= <b>function</b> funcname funcbody
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1778 stat ::= <b>local</b> <b>function</b> Name funcbody
243
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diff changeset
1779 funcname ::= Name {&lsquo;<b>.</b>&rsquo; Name}
239
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diff changeset
1780 </pre><p>
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parents:
diff changeset
1781 The statement
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diff changeset
1782
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parents:
diff changeset
1783 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1784 function f () <em>body</em> end
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parents:
diff changeset
1785 </pre><p>
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parents:
diff changeset
1786 translates to
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diff changeset
1787
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parents:
diff changeset
1788 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1789 f = function () <em>body</em> end
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diff changeset
1790 </pre><p>
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parents:
diff changeset
1791 The statement
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diff changeset
1792
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parents:
diff changeset
1793 <pre>
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parents:
diff changeset
1794 function t.a.b.c.f () <em>body</em> end
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1795 </pre><p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1796 translates to
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1797
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1798 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1799 t.a.b.c.f = function () <em>body</em> end
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1800 </pre><p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1801 The statement
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parents:
diff changeset
1802
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1803 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1804 local function f () <em>body</em> end
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1805 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1806 translates to
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1807
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1808 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1809 local f; f = function () <em>body</em> end
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1810 </pre><p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1811 not to
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1812
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1813 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1814 local f = function () <em>body</em> end
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1815 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1816 (This only makes a difference when the body of the function
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1817 contains references to <code>f</code>.)
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1818
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1819
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1820 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1821 A function definition is an executable expression,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1822 whose value has type <em>function</em>.
243
c912f6de2053 more work on the manual
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parents: 242
diff changeset
1823 When Luan precompiles a chunk,
239
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parents:
diff changeset
1824 all its function bodies are precompiled too.
243
c912f6de2053 more work on the manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 242
diff changeset
1825 Then, whenever Luan executes the function definition,
239
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1826 the function is <em>instantiated</em> (or <em>closed</em>).
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1827 This function instance (or <em>closure</em>)
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1828 is the final value of the expression.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1829
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parents:
diff changeset
1830
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1831 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1832 Parameters act as local variables that are
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1833 initialized with the argument values:
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1834
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1835 <pre>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1836 parlist ::= namelist [&lsquo;<b>,</b>&rsquo; &lsquo;<b>...</b>&rsquo;] | &lsquo;<b>...</b>&rsquo;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1837 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1838 When a function is called,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1839 the list of arguments is adjusted to
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1840 the length of the list of parameters,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1841 unless the function is a <em>vararg function</em>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1842 which is indicated by three dots ('<code>...</code>')
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1843 at the end of its parameter list.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1844 A vararg function does not adjust its argument list;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1845 instead, it collects all extra arguments and supplies them
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1846 to the function through a <em>vararg expression</em>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1847 which is also written as three dots.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1848 The value of this expression is a list of all actual extra arguments,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1849 similar to a function with multiple results.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1850 If a vararg expression is used inside another expression
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1851 or in the middle of a list of expressions,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1852 then its return list is adjusted to one element.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1853 If the expression is used as the last element of a list of expressions,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1854 then no adjustment is made
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1855 (unless that last expression is enclosed in parentheses).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1856
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1857
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1858 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1859 As an example, consider the following definitions:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1860
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1861 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1862 function f(a, b) end
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1863 function g(a, b, ...) end
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1864 function r() return 1,2,3 end
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1865 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1866 Then, we have the following mapping from arguments to parameters and
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1867 to the vararg expression:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1868
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1869 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1870 CALL PARAMETERS
242
b5a926c481a5 Handle first h1 tag differently.
hugo.tech@gmail.com <hugo.tech@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 241
diff changeset
1871
239
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1872 f(3) a=3, b=nil
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1873 f(3, 4) a=3, b=4
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1874 f(3, 4, 5) a=3, b=4
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1875 f(r(), 10) a=1, b=10
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1876 f(r()) a=1, b=2
242
b5a926c481a5 Handle first h1 tag differently.
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parents: 241
diff changeset
1877
239
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parents:
diff changeset
1878 g(3) a=3, b=nil, ... --&gt; (nothing)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1879 g(3, 4) a=3, b=4, ... --&gt; (nothing)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1880 g(3, 4, 5, 8) a=3, b=4, ... --&gt; 5 8
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1881 g(5, r()) a=5, b=1, ... --&gt; 2 3
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1882 </pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1883
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1884 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1885 Results are returned using the <b>return</b> statement (see <a href="#3.3.4">&sect;3.3.4</a>).
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1886 If control reaches the end of a function
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1887 without encountering a <b>return</b> statement,
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1888 then the function returns with no results.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1889
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parents:
diff changeset
1890
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1891
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1892
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1893 <h2>3.5 &ndash; <a name="3.5">Visibility Rules</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
1894
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1895 <p>
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1896
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1897 Luan is a lexically scoped language.
239
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1898 The scope of a local variable begins at the first statement after
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1899 its declaration and lasts until the last non-void statement
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1900 of the innermost block that includes the declaration.
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diff changeset
1901 Consider the following example:
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1902
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1903 <pre>
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1904 x = 10 -- global variable
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1905 do -- new block
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1906 local x = x -- new 'x', with value 10
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1907 print(x) --&gt; 10
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1908 x = x+1
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1909 do -- another block
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1910 local x = x+1 -- another 'x'
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1911 print(x) --&gt; 12
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1912 end
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1913 print(x) --&gt; 11
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1914 end
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1915 print(x) --&gt; 10 (the global one)
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1916 </pre>
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1917
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1918 <p>
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diff changeset
1919 Notice that, in a declaration like <code>local x = x</code>,
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1920 the new <code>x</code> being declared is not in scope yet,
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1921 and so the second <code>x</code> refers to the outside variable.
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1922
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1923
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1924 <p>
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diff changeset
1925 Because of the lexical scoping rules,
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1926 local variables can be freely accessed by functions
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1927 defined inside their scope.
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1928 A local variable used by an inner function is called
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1929 an <em>upvalue</em>, or <em>external local variable</em>,
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1930 inside the inner function.
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1931
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1932
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1933 <p>
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diff changeset
1934 Notice that each execution of a <b>local</b> statement
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1935 defines new local variables.
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diff changeset
1936 Consider the following example:
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1937
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1938 <pre>
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1939 a = {}
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1940 local x = 20
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diff changeset
1941 for i=1,10 do
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1942 local y = 0
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1943 a[i] = function () y=y+1; return x+y end
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1944 end
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1945 </pre><p>
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diff changeset
1946 The loop creates ten closures
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diff changeset
1947 (that is, ten instances of the anonymous function).
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diff changeset
1948 Each of these closures uses a different <code>y</code> variable,
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diff changeset
1949 while all of them share the same <code>x</code>.
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1950
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1951
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1952
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1953
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diff changeset
1954
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diff changeset
1955 <h1>4 &ndash; <a name="4">The Application Program Interface</a></h1>
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1956
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1957 <p>
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1958 In the Lua documentation,
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diff changeset
1959 this section described the C&nbsp;API for Lua.
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diff changeset
1960 Obviously this is not relevant for Luan.
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diff changeset
1961 The implementation of Luan is radically different from Lua and will be documented eventually in Javadoc.
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diff changeset
1962 So this section is just a placeholder so that Luan documentation can match Lua's documentation.
239
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1963
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diff changeset
1964
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diff changeset
1965
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diff changeset
1966
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diff changeset
1967 <h1>5 &ndash; <a name="5">The Auxiliary Library</a></h1>
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1968
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1969 <p>
243
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diff changeset
1970 Like the previous section, this section is specific to Lua and is not relevant to Luan.
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diff changeset
1971 So this section is just a placeholder.
239
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diff changeset
1972
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diff changeset
1973
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diff changeset
1974
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diff changeset
1975
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diff changeset
1976
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diff changeset
1977 <h1>6 &ndash; <a name="6">Standard Libraries</a></h1>
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1978
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1979 <p>
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diff changeset
1980 The standard Lua libraries provide useful functions
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diff changeset
1981 that are implemented directly through the C&nbsp;API.
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diff changeset
1982 Some of these functions provide essential services to the language
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diff changeset
1983 (e.g., <a href="#pdf-type"><code>type</code></a> and <a href="#pdf-getmetatable"><code>getmetatable</code></a>);
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diff changeset
1984 others provide access to "outside" services (e.g., I/O);
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diff changeset
1985 and others could be implemented in Lua itself,
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parents:
diff changeset
1986 but are quite useful or have critical performance requirements that
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parents:
diff changeset
1987 deserve an implementation in C (e.g., <a href="#pdf-table.sort"><code>table.sort</code></a>).
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parents:
diff changeset
1988
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parents:
diff changeset
1989
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parents:
diff changeset
1990 <p>
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parents:
diff changeset
1991 All libraries are implemented through the official C&nbsp;API
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parents:
diff changeset
1992 and are provided as separate C&nbsp;modules.
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diff changeset
1993 Currently, Lua has the following standard libraries:
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diff changeset
1994
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parents:
diff changeset
1995 <ul>
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parents:
diff changeset
1996
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parents:
diff changeset
1997 <li>basic library (<a href="#6.1">&sect;6.1</a>);</li>
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diff changeset
1998
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diff changeset
1999 <li>coroutine library (<a href="#6.2">&sect;6.2</a>);</li>
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parents:
diff changeset
2000
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parents:
diff changeset
2001 <li>package library (<a href="#6.3">&sect;6.3</a>);</li>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2002
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parents:
diff changeset
2003 <li>string manipulation (<a href="#6.4">&sect;6.4</a>);</li>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2004
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parents:
diff changeset
2005 <li>table manipulation (<a href="#6.5">&sect;6.5</a>);</li>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2006
aa7bc9c1df22 add unedited Lua manual
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diff changeset
2007 <li>mathematical functions (<a href="#6.6">&sect;6.6</a>) (sin, log, etc.);</li>
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parents:
diff changeset
2008
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2009 <li>bitwise operations (<a href="#6.7">&sect;6.7</a>);</li>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2010
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2011 <li>input and output (<a href="#6.8">&sect;6.8</a>);</li>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2012
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2013 <li>operating system facilities (<a href="#6.9">&sect;6.9</a>);</li>
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parents:
diff changeset
2014
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2015 <li>debug facilities (<a href="#6.10">&sect;6.10</a>).</li>
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parents:
diff changeset
2016
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2017 </ul><p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2018 Except for the basic and the package libraries,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2019 each library provides all its functions as fields of a global table
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2020 or as methods of its objects.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2021
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parents:
diff changeset
2022
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2023 <p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2024 To have access to these libraries,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2025 the C&nbsp;host program should call the <a href="#luaL_openlibs"><code>luaL_openlibs</code></a> function,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2026 which opens all standard libraries.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2027 Alternatively,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2028 the host program can open them individually by using
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2029 <a href="#luaL_requiref"><code>luaL_requiref</code></a> to call
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2030 <a name="pdf-luaopen_base"><code>luaopen_base</code></a> (for the basic library),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2031 <a name="pdf-luaopen_package"><code>luaopen_package</code></a> (for the package library),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2032 <a name="pdf-luaopen_coroutine"><code>luaopen_coroutine</code></a> (for the coroutine library),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2033 <a name="pdf-luaopen_string"><code>luaopen_string</code></a> (for the string library),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2034 <a name="pdf-luaopen_table"><code>luaopen_table</code></a> (for the table library),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2035 <a name="pdf-luaopen_math"><code>luaopen_math</code></a> (for the mathematical library),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2036 <a name="pdf-luaopen_bit32"><code>luaopen_bit32</code></a> (for the bit library),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2037 <a name="pdf-luaopen_io"><code>luaopen_io</code></a> (for the I/O library),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2038 <a name="pdf-luaopen_os"><code>luaopen_os</code></a> (for the Operating System library),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2039 and <a name="pdf-luaopen_debug"><code>luaopen_debug</code></a> (for the debug library).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2040 These functions are declared in <a name="pdf-lualib.h"><code>lualib.h</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2041
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2042
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2043
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2044 <h2>6.1 &ndash; <a name="6.1">Basic Functions</a></h2>
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parents:
diff changeset
2045
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2046 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2047 The basic library provides core functions to Lua.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2048 If you do not include this library in your application,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2049 you should check carefully whether you need to provide
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2050 implementations for some of its facilities.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2051
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2052
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2053 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2054 <hr><h3><a name="pdf-assert"><code>assert (v [, message])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2055 Issues an error when
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2056 the value of its argument <code>v</code> is false (i.e., <b>nil</b> or <b>false</b>);
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2057 otherwise, returns all its arguments.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2058 <code>message</code> is an error message;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2059 when absent, it defaults to "assertion failed!"
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2060
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2061
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2062
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2063
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2064 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2065 <hr><h3><a name="pdf-collectgarbage"><code>collectgarbage ([opt [, arg]])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2066
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2067
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2068 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2069 This function is a generic interface to the garbage collector.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2070 It performs different functions according to its first argument, <code>opt</code>:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2071
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2072 <ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2073
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2074 <li><b>"<code>collect</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2075 performs a full garbage-collection cycle.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2076 This is the default option.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2077 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2078
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2079 <li><b>"<code>stop</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2080 stops automatic execution of the garbage collector.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2081 The collector will run only when explicitly invoked,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2082 until a call to restart it.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2083 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2084
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2085 <li><b>"<code>restart</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2086 restarts automatic execution of the garbage collector.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2087 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2088
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2089 <li><b>"<code>count</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2090 returns the total memory in use by Lua (in Kbytes) and
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2091 a second value with the total memory in bytes modulo 1024.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2092 The first value has a fractional part,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2093 so the following equality is always true:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2094
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2095 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2096 k, b = collectgarbage("count")
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2097 assert(k*1024 == math.floor(k)*1024 + b)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2098 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2099 (The second result is useful when Lua is compiled
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2100 with a non floating-point type for numbers.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2101 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2102
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2103 <li><b>"<code>step</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2104 performs a garbage-collection step.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2105 The step "size" is controlled by <code>arg</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2106 (larger values mean more steps) in a non-specified way.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2107 If you want to control the step size
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2108 you must experimentally tune the value of <code>arg</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2109 Returns <b>true</b> if the step finished a collection cycle.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2110 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2111
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2112 <li><b>"<code>setpause</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2113 sets <code>arg</code> as the new value for the <em>pause</em> of
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2114 the collector (see <a href="#2.5">&sect;2.5</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2115 Returns the previous value for <em>pause</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2116 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2117
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2118 <li><b>"<code>setstepmul</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2119 sets <code>arg</code> as the new value for the <em>step multiplier</em> of
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2120 the collector (see <a href="#2.5">&sect;2.5</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2121 Returns the previous value for <em>step</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2122 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2123
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2124 <li><b>"<code>isrunning</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2125 returns a boolean that tells whether the collector is running
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2126 (i.e., not stopped).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2127 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2128
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2129 <li><b>"<code>generational</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2130 changes the collector to generational mode.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2131 This is an experimental feature (see <a href="#2.5">&sect;2.5</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2132 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2133
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2134 <li><b>"<code>incremental</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2135 changes the collector to incremental mode.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2136 This is the default mode.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2137 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2138
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2139 </ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2140
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2141
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2142
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2143 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2144 <hr><h3><a name="pdf-dofile"><code>dofile ([filename])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2145 Opens the named file and executes its contents as a Lua chunk.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2146 When called without arguments,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2147 <code>dofile</code> executes the contents of the standard input (<code>stdin</code>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2148 Returns all values returned by the chunk.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2149 In case of errors, <code>dofile</code> propagates the error
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2150 to its caller (that is, <code>dofile</code> does not run in protected mode).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2151
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2152
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2153
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2154
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2155 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2156 <hr><h3><a name="pdf-error"><code>error (message [, level])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2157 Terminates the last protected function called
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2158 and returns <code>message</code> as the error message.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2159 Function <code>error</code> never returns.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2160
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2161
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2162 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2163 Usually, <code>error</code> adds some information about the error position
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2164 at the beginning of the message, if the message is a string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2165 The <code>level</code> argument specifies how to get the error position.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2166 With level&nbsp;1 (the default), the error position is where the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2167 <code>error</code> function was called.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2168 Level&nbsp;2 points the error to where the function
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2169 that called <code>error</code> was called; and so on.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2170 Passing a level&nbsp;0 avoids the addition of error position information
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2171 to the message.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2172
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2173
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2174
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2175
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2176 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2177 <hr><h3><a name="pdf-_G"><code>_G</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2178 A global variable (not a function) that
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2179 holds the global environment (see <a href="#2.2">&sect;2.2</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2180 Lua itself does not use this variable;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2181 changing its value does not affect any environment,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2182 nor vice-versa.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2183
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2184
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2185
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2186
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2187 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2188 <hr><h3><a name="pdf-getmetatable"><code>getmetatable (object)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2189
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2190
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2191 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2192 If <code>object</code> does not have a metatable, returns <b>nil</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2193 Otherwise,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2194 if the object's metatable has a <code>"__metatable"</code> field,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2195 returns the associated value.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2196 Otherwise, returns the metatable of the given object.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2197
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2198
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2199
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2200
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2201 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2202 <hr><h3><a name="pdf-ipairs"><code>ipairs (t)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2203
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2204
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2205 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2206 If <code>t</code> has a metamethod <code>__ipairs</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2207 calls it with <code>t</code> as argument and returns the first three
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2208 results from the call.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2209
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2210
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2211 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2212 Otherwise,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2213 returns three values: an iterator function, the table <code>t</code>, and 0,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2214 so that the construction
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2215
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2216 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2217 for i,v in ipairs(t) do <em>body</em> end
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2218 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2219 will iterate over the pairs (<code>1,t[1]</code>), (<code>2,t[2]</code>), ...,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2220 up to the first integer key absent from the table.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2221
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2222
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2223
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2224
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2225 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2226 <hr><h3><a name="pdf-load"><code>load (ld [, source [, mode [, env]]])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2227
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2228
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2229 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2230 Loads a chunk.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2231
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2232
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2233 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2234 If <code>ld</code> is a string, the chunk is this string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2235 If <code>ld</code> is a function,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2236 <code>load</code> calls it repeatedly to get the chunk pieces.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2237 Each call to <code>ld</code> must return a string that concatenates
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2238 with previous results.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2239 A return of an empty string, <b>nil</b>, or no value signals the end of the chunk.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2240
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2241
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2242 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2243 If there are no syntactic errors,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2244 returns the compiled chunk as a function;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2245 otherwise, returns <b>nil</b> plus the error message.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2246
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2247
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2248 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2249 If the resulting function has upvalues,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2250 the first upvalue is set to the value of <code>env</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2251 if that parameter is given,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2252 or to the value of the global environment.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2253 (When you load a main chunk,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2254 the resulting function will always have exactly one upvalue,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2255 the <code>_ENV</code> variable (see <a href="#2.2">&sect;2.2</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2256 When you load a binary chunk created from a function (see <a href="#pdf-string.dump"><code>string.dump</code></a>),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2257 the resulting function can have arbitrary upvalues.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2258
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2259
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2260 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2261 <code>source</code> is used as the source of the chunk for error messages
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2262 and debug information (see <a href="#4.9">&sect;4.9</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2263 When absent,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2264 it defaults to <code>ld</code>, if <code>ld</code> is a string,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2265 or to "<code>=(load)</code>" otherwise.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2266
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2267
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2268 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2269 The string <code>mode</code> controls whether the chunk can be text or binary
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2270 (that is, a precompiled chunk).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2271 It may be the string "<code>b</code>" (only binary chunks),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2272 "<code>t</code>" (only text chunks),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2273 or "<code>bt</code>" (both binary and text).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2274 The default is "<code>bt</code>".
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2275
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2276
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2277
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2278
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2279 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2280 <hr><h3><a name="pdf-loadfile"><code>loadfile ([filename [, mode [, env]]])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2281
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2282
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2283 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2284 Similar to <a href="#pdf-load"><code>load</code></a>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2285 but gets the chunk from file <code>filename</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2286 or from the standard input,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2287 if no file name is given.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2288
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2289
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2290
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2291
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2292 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2293 <hr><h3><a name="pdf-next"><code>next (table [, index])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2294
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2295
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2296 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2297 Allows a program to traverse all fields of a table.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2298 Its first argument is a table and its second argument
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2299 is an index in this table.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2300 <code>next</code> returns the next index of the table
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2301 and its associated value.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2302 When called with <b>nil</b> as its second argument,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2303 <code>next</code> returns an initial index
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2304 and its associated value.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2305 When called with the last index,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2306 or with <b>nil</b> in an empty table,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2307 <code>next</code> returns <b>nil</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2308 If the second argument is absent, then it is interpreted as <b>nil</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2309 In particular,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2310 you can use <code>next(t)</code> to check whether a table is empty.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2311
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2312
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2313 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2314 The order in which the indices are enumerated is not specified,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2315 <em>even for numeric indices</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2316 (To traverse a table in numeric order,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2317 use a numerical <b>for</b>.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2318
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2319
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2320 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2321 The behavior of <code>next</code> is undefined if,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2322 during the traversal,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2323 you assign any value to a non-existent field in the table.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2324 You may however modify existing fields.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2325 In particular, you may clear existing fields.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2326
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2327
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2328
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2329
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2330 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2331 <hr><h3><a name="pdf-pairs"><code>pairs (t)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2332
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2333
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2334 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2335 If <code>t</code> has a metamethod <code>__pairs</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2336 calls it with <code>t</code> as argument and returns the first three
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2337 results from the call.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2338
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2339
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2340 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2341 Otherwise,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2342 returns three values: the <a href="#pdf-next"><code>next</code></a> function, the table <code>t</code>, and <b>nil</b>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2343 so that the construction
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2344
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2345 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2346 for k,v in pairs(t) do <em>body</em> end
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2347 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2348 will iterate over all key&ndash;value pairs of table <code>t</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2349
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2350
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2351 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2352 See function <a href="#pdf-next"><code>next</code></a> for the caveats of modifying
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2353 the table during its traversal.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2354
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2355
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2356
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2357
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2358 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2359 <hr><h3><a name="pdf-pcall"><code>pcall (f [, arg1, &middot;&middot;&middot;])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2360
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2361
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2362 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2363 Calls function <code>f</code> with
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2364 the given arguments in <em>protected mode</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2365 This means that any error inside&nbsp;<code>f</code> is not propagated;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2366 instead, <code>pcall</code> catches the error
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2367 and returns a status code.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2368 Its first result is the status code (a boolean),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2369 which is true if the call succeeds without errors.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2370 In such case, <code>pcall</code> also returns all results from the call,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2371 after this first result.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2372 In case of any error, <code>pcall</code> returns <b>false</b> plus the error message.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2373
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2374
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2375
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2376
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2377 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2378 <hr><h3><a name="pdf-print"><code>print (&middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2379 Receives any number of arguments
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2380 and prints their values to <code>stdout</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2381 using the <a href="#pdf-tostring"><code>tostring</code></a> function to convert each argument to a string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2382 <code>print</code> is not intended for formatted output,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2383 but only as a quick way to show a value,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2384 for instance for debugging.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2385 For complete control over the output,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2386 use <a href="#pdf-string.format"><code>string.format</code></a> and <a href="#pdf-io.write"><code>io.write</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2387
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2388
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2389
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2390
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2391 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2392 <hr><h3><a name="pdf-rawequal"><code>rawequal (v1, v2)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2393 Checks whether <code>v1</code> is equal to <code>v2</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2394 without invoking any metamethod.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2395 Returns a boolean.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2396
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2397
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2398
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2399
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2400 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2401 <hr><h3><a name="pdf-rawget"><code>rawget (table, index)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2402 Gets the real value of <code>table[index]</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2403 without invoking any metamethod.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2404 <code>table</code> must be a table;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2405 <code>index</code> may be any value.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2406
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2407
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2408
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2409
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2410 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2411 <hr><h3><a name="pdf-rawlen"><code>rawlen (v)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2412 Returns the length of the object <code>v</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2413 which must be a table or a string,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2414 without invoking any metamethod.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2415 Returns an integer number.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2416
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2417
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2418
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2419
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2420 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2421 <hr><h3><a name="pdf-rawset"><code>rawset (table, index, value)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2422 Sets the real value of <code>table[index]</code> to <code>value</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2423 without invoking any metamethod.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2424 <code>table</code> must be a table,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2425 <code>index</code> any value different from <b>nil</b> and NaN,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2426 and <code>value</code> any Lua value.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2427
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2428
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2429 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2430 This function returns <code>table</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2431
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2432
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2433
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2434
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2435 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2436 <hr><h3><a name="pdf-select"><code>select (index, &middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2437
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2438
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2439 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2440 If <code>index</code> is a number,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2441 returns all arguments after argument number <code>index</code>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2442 a negative number indexes from the end (-1 is the last argument).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2443 Otherwise, <code>index</code> must be the string <code>"#"</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2444 and <code>select</code> returns the total number of extra arguments it received.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2445
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2446
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2447
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2448
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2449 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2450 <hr><h3><a name="pdf-setmetatable"><code>setmetatable (table, metatable)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2451
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2452
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2453 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2454 Sets the metatable for the given table.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2455 (You cannot change the metatable of other types from Lua, only from&nbsp;C.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2456 If <code>metatable</code> is <b>nil</b>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2457 removes the metatable of the given table.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2458 If the original metatable has a <code>"__metatable"</code> field,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2459 raises an error.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2460
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2461
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2462 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2463 This function returns <code>table</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2464
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2465
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2466
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2467
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2468 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2469 <hr><h3><a name="pdf-tonumber"><code>tonumber (e [, base])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2470
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2471
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2472 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2473 When called with no <code>base</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2474 <code>tonumber</code> tries to convert its argument to a number.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2475 If the argument is already a number or
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2476 a string convertible to a number (see <a href="#3.4.2">&sect;3.4.2</a>),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2477 then <code>tonumber</code> returns this number;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2478 otherwise, it returns <b>nil</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2479
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2480
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2481 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2482 When called with <code>base</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2483 then <code>e</code> should be a string to be interpreted as
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2484 an integer numeral in that base.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2485 The base may be any integer between 2 and 36, inclusive.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2486 In bases above&nbsp;10, the letter '<code>A</code>' (in either upper or lower case)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2487 represents&nbsp;10, '<code>B</code>' represents&nbsp;11, and so forth,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2488 with '<code>Z</code>' representing 35.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2489 If the string <code>e</code> is not a valid numeral in the given base,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2490 the function returns <b>nil</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2491
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2492
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2493
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2494
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2495 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2496 <hr><h3><a name="pdf-tostring"><code>tostring (v)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2497 Receives a value of any type and
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2498 converts it to a string in a reasonable format.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2499 (For complete control of how numbers are converted,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2500 use <a href="#pdf-string.format"><code>string.format</code></a>.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2501
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2502
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2503 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2504 If the metatable of <code>v</code> has a <code>"__tostring"</code> field,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2505 then <code>tostring</code> calls the corresponding value
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2506 with <code>v</code> as argument,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2507 and uses the result of the call as its result.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2508
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2509
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2510
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2511
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2512 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2513 <hr><h3><a name="pdf-type"><code>type (v)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2514 Returns the type of its only argument, coded as a string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2515 The possible results of this function are
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2516 "<code>nil</code>" (a string, not the value <b>nil</b>),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2517 "<code>number</code>",
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2518 "<code>string</code>",
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2519 "<code>boolean</code>",
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2520 "<code>table</code>",
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2521 "<code>function</code>",
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2522 "<code>thread</code>",
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2523 and "<code>userdata</code>".
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2524
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2525
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2526
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2527
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2528 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2529 <hr><h3><a name="pdf-_VERSION"><code>_VERSION</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2530 A global variable (not a function) that
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2531 holds a string containing the current interpreter version.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2532 The current contents of this variable is "<code>Lua 5.2</code>".
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2533
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2534
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2535
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2536
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2537 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2538 <hr><h3><a name="pdf-xpcall"><code>xpcall (f, msgh [, arg1, &middot;&middot;&middot;])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2539
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2540
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2541 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2542 This function is similar to <a href="#pdf-pcall"><code>pcall</code></a>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2543 except that it sets a new message handler <code>msgh</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2544
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2545
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2546
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2547
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2548
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2549
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2550
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2551 <h2>6.2 &ndash; <a name="6.2">Coroutine Manipulation</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2552
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2553 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2554 The operations related to coroutines comprise a sub-library of
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2555 the basic library and come inside the table <a name="pdf-coroutine"><code>coroutine</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2556 See <a href="#2.6">&sect;2.6</a> for a general description of coroutines.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2557
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2558
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2559 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2560 <hr><h3><a name="pdf-coroutine.create"><code>coroutine.create (f)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2561
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2562
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2563 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2564 Creates a new coroutine, with body <code>f</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2565 <code>f</code> must be a Lua function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2566 Returns this new coroutine,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2567 an object with type <code>"thread"</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2568
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2569
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2570
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2571
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2572 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2573 <hr><h3><a name="pdf-coroutine.resume"><code>coroutine.resume (co [, val1, &middot;&middot;&middot;])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2574
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2575
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2576 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2577 Starts or continues the execution of coroutine <code>co</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2578 The first time you resume a coroutine,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2579 it starts running its body.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2580 The values <code>val1</code>, ... are passed
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2581 as the arguments to the body function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2582 If the coroutine has yielded,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2583 <code>resume</code> restarts it;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2584 the values <code>val1</code>, ... are passed
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2585 as the results from the yield.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2586
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2587
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2588 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2589 If the coroutine runs without any errors,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2590 <code>resume</code> returns <b>true</b> plus any values passed to <code>yield</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2591 (if the coroutine yields) or any values returned by the body function
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2592 (if the coroutine terminates).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2593 If there is any error,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2594 <code>resume</code> returns <b>false</b> plus the error message.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2595
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parents:
diff changeset
2596
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2597
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2598
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2599 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2600 <hr><h3><a name="pdf-coroutine.running"><code>coroutine.running ()</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2601
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2602
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2603 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2604 Returns the running coroutine plus a boolean,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2605 true when the running coroutine is the main one.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2606
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2607
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2608
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2609
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2610 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2611 <hr><h3><a name="pdf-coroutine.status"><code>coroutine.status (co)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2612
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2613
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2614 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2615 Returns the status of coroutine <code>co</code>, as a string:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2616 <code>"running"</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2617 if the coroutine is running (that is, it called <code>status</code>);
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2618 <code>"suspended"</code>, if the coroutine is suspended in a call to <code>yield</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2619 or if it has not started running yet;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2620 <code>"normal"</code> if the coroutine is active but not running
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2621 (that is, it has resumed another coroutine);
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2622 and <code>"dead"</code> if the coroutine has finished its body function,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2623 or if it has stopped with an error.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2624
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2625
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2626
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2627
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2628 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2629 <hr><h3><a name="pdf-coroutine.wrap"><code>coroutine.wrap (f)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2630
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2631
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2632 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2633 Creates a new coroutine, with body <code>f</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2634 <code>f</code> must be a Lua function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2635 Returns a function that resumes the coroutine each time it is called.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2636 Any arguments passed to the function behave as the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2637 extra arguments to <code>resume</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2638 Returns the same values returned by <code>resume</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2639 except the first boolean.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2640 In case of error, propagates the error.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2641
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parents:
diff changeset
2642
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2643
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2644
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2645 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2646 <hr><h3><a name="pdf-coroutine.yield"><code>coroutine.yield (&middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2647
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2648
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2649 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2650 Suspends the execution of the calling coroutine.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2651 Any arguments to <code>yield</code> are passed as extra results to <code>resume</code>.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2652
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2653
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2654
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2655
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2656
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2657
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2658
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2659 <h2>6.3 &ndash; <a name="6.3">Modules</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2660
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2661 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2662 The package library provides basic
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2663 facilities for loading modules in Lua.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2664 It exports one function directly in the global environment:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2665 <a href="#pdf-require"><code>require</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2666 Everything else is exported in a table <a name="pdf-package"><code>package</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2667
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2668
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2669 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2670 <hr><h3><a name="pdf-require"><code>require (modname)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2671
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2672
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2673 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2674 Loads the given module.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2675 The function starts by looking into the <a href="#pdf-package.loaded"><code>package.loaded</code></a> table
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2676 to determine whether <code>modname</code> is already loaded.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2677 If it is, then <code>require</code> returns the value stored
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2678 at <code>package.loaded[modname]</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2679 Otherwise, it tries to find a <em>loader</em> for the module.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2680
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2681
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2682 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2683 To find a loader,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2684 <code>require</code> is guided by the <a href="#pdf-package.searchers"><code>package.searchers</code></a> sequence.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2685 By changing this sequence,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2686 we can change how <code>require</code> looks for a module.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2687 The following explanation is based on the default configuration
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2688 for <a href="#pdf-package.searchers"><code>package.searchers</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2689
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2690
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2691 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2692 First <code>require</code> queries <code>package.preload[modname]</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2693 If it has a value,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2694 this value (which should be a function) is the loader.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2695 Otherwise <code>require</code> searches for a Lua loader using the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2696 path stored in <a href="#pdf-package.path"><code>package.path</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2697 If that also fails, it searches for a C&nbsp;loader using the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2698 path stored in <a href="#pdf-package.cpath"><code>package.cpath</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2699 If that also fails,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2700 it tries an <em>all-in-one</em> loader (see <a href="#pdf-package.searchers"><code>package.searchers</code></a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2701
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2702
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2703 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2704 Once a loader is found,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2705 <code>require</code> calls the loader with two arguments:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2706 <code>modname</code> and an extra value dependent on how it got the loader.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2707 (If the loader came from a file,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2708 this extra value is the file name.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2709 If the loader returns any non-nil value,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2710 <code>require</code> assigns the returned value to <code>package.loaded[modname]</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2711 If the loader does not return a non-nil value and
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2712 has not assigned any value to <code>package.loaded[modname]</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2713 then <code>require</code> assigns <b>true</b> to this entry.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2714 In any case, <code>require</code> returns the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2715 final value of <code>package.loaded[modname]</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2716
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2717
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2718 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2719 If there is any error loading or running the module,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2720 or if it cannot find any loader for the module,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2721 then <code>require</code> raises an error.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2722
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2723
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2724
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2725
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2726 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2727 <hr><h3><a name="pdf-package.config"><code>package.config</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2728
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2729
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2730 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2731 A string describing some compile-time configurations for packages.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2732 This string is a sequence of lines:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2733
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2734 <ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2735
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2736 <li>The first line is the directory separator string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2737 Default is '<code>\</code>' for Windows and '<code>/</code>' for all other systems.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2738
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2739 <li>The second line is the character that separates templates in a path.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2740 Default is '<code>;</code>'.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2741
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2742 <li>The third line is the string that marks the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2743 substitution points in a template.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2744 Default is '<code>?</code>'.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2745
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2746 <li>The fourth line is a string that, in a path in Windows,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2747 is replaced by the executable's directory.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2748 Default is '<code>!</code>'.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2749
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2750 <li>The fifth line is a mark to ignore all text before it
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2751 when building the <code>luaopen_</code> function name.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2752 Default is '<code>-</code>'.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2753
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2754 </ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2755
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2756
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2757
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2758 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2759 <hr><h3><a name="pdf-package.cpath"><code>package.cpath</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2760
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2761
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2762 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2763 The path used by <a href="#pdf-require"><code>require</code></a> to search for a C&nbsp;loader.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2764
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2765
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2766 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2767 Lua initializes the C&nbsp;path <a href="#pdf-package.cpath"><code>package.cpath</code></a> in the same way
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2768 it initializes the Lua path <a href="#pdf-package.path"><code>package.path</code></a>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2769 using the environment variable <a name="pdf-LUA_CPATH_5_2"><code>LUA_CPATH_5_2</code></a>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2770 or the environment variable <a name="pdf-LUA_CPATH"><code>LUA_CPATH</code></a>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2771 or a default path defined in <code>luaconf.h</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2772
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2773
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2774
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2775
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2776 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2777 <hr><h3><a name="pdf-package.loaded"><code>package.loaded</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2778
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2779
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2780 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2781 A table used by <a href="#pdf-require"><code>require</code></a> to control which
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2782 modules are already loaded.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2783 When you require a module <code>modname</code> and
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2784 <code>package.loaded[modname]</code> is not false,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2785 <a href="#pdf-require"><code>require</code></a> simply returns the value stored there.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2786
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2787
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2788 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2789 This variable is only a reference to the real table;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2790 assignments to this variable do not change the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2791 table used by <a href="#pdf-require"><code>require</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2792
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2793
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2794
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2795
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2796 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2797 <hr><h3><a name="pdf-package.loadlib"><code>package.loadlib (libname, funcname)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2798
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2799
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2800 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2801 Dynamically links the host program with the C&nbsp;library <code>libname</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2802
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2803
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2804 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2805 If <code>funcname</code> is "<code>*</code>",
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2806 then it only links with the library,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2807 making the symbols exported by the library
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2808 available to other dynamically linked libraries.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2809 Otherwise,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2810 it looks for a function <code>funcname</code> inside the library
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2811 and returns this function as a C&nbsp;function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2812 So, <code>funcname</code> must follow the <a href="#lua_CFunction"><code>lua_CFunction</code></a> prototype
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2813 (see <a href="#lua_CFunction"><code>lua_CFunction</code></a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2814
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2815
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2816 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2817 This is a low-level function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2818 It completely bypasses the package and module system.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2819 Unlike <a href="#pdf-require"><code>require</code></a>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2820 it does not perform any path searching and
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2821 does not automatically adds extensions.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2822 <code>libname</code> must be the complete file name of the C&nbsp;library,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2823 including if necessary a path and an extension.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2824 <code>funcname</code> must be the exact name exported by the C&nbsp;library
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2825 (which may depend on the C&nbsp;compiler and linker used).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2826
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2827
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2828 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2829 This function is not supported by Standard&nbsp;C.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2830 As such, it is only available on some platforms
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2831 (Windows, Linux, Mac OS X, Solaris, BSD,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2832 plus other Unix systems that support the <code>dlfcn</code> standard).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2833
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2834
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2835
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2836
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2837 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2838 <hr><h3><a name="pdf-package.path"><code>package.path</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2839
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2840
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2841 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2842 The path used by <a href="#pdf-require"><code>require</code></a> to search for a Lua loader.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2843
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2844
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2845 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2846 At start-up, Lua initializes this variable with
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2847 the value of the environment variable <a name="pdf-LUA_PATH_5_2"><code>LUA_PATH_5_2</code></a> or
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2848 the environment variable <a name="pdf-LUA_PATH"><code>LUA_PATH</code></a> or
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2849 with a default path defined in <code>luaconf.h</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2850 if those environment variables are not defined.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2851 Any "<code>;;</code>" in the value of the environment variable
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2852 is replaced by the default path.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2853
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
2854
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2855
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2856
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2857 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2858 <hr><h3><a name="pdf-package.preload"><code>package.preload</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2859
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2860
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2861 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2862 A table to store loaders for specific modules
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2863 (see <a href="#pdf-require"><code>require</code></a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2864
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2865
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2866 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2867 This variable is only a reference to the real table;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2868 assignments to this variable do not change the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2869 table used by <a href="#pdf-require"><code>require</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2870
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2871
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2872
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2873
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2874 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2875 <hr><h3><a name="pdf-package.searchers"><code>package.searchers</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2876
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2877
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2878 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2879 A table used by <a href="#pdf-require"><code>require</code></a> to control how to load modules.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2880
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2881
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2882 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2883 Each entry in this table is a <em>searcher function</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2884 When looking for a module,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2885 <a href="#pdf-require"><code>require</code></a> calls each of these searchers in ascending order,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2886 with the module name (the argument given to <a href="#pdf-require"><code>require</code></a>) as its
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2887 sole parameter.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2888 The function can return another function (the module <em>loader</em>)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2889 plus an extra value that will be passed to that loader,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2890 or a string explaining why it did not find that module
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2891 (or <b>nil</b> if it has nothing to say).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2892
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2893
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2894 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2895 Lua initializes this table with four searcher functions.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2896
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2897
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2898 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2899 The first searcher simply looks for a loader in the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2900 <a href="#pdf-package.preload"><code>package.preload</code></a> table.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2901
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2902
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2903 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2904 The second searcher looks for a loader as a Lua library,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2905 using the path stored at <a href="#pdf-package.path"><code>package.path</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2906 The search is done as described in function <a href="#pdf-package.searchpath"><code>package.searchpath</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2907
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2908
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2909 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2910 The third searcher looks for a loader as a C&nbsp;library,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2911 using the path given by the variable <a href="#pdf-package.cpath"><code>package.cpath</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2912 Again,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2913 the search is done as described in function <a href="#pdf-package.searchpath"><code>package.searchpath</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2914 For instance,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2915 if the C&nbsp;path is the string
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2916
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2917 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2918 "./?.so;./?.dll;/usr/local/?/init.so"
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2919 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2920 the searcher for module <code>foo</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2921 will try to open the files <code>./foo.so</code>, <code>./foo.dll</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2922 and <code>/usr/local/foo/init.so</code>, in that order.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2923 Once it finds a C&nbsp;library,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2924 this searcher first uses a dynamic link facility to link the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2925 application with the library.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2926 Then it tries to find a C&nbsp;function inside the library to
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2927 be used as the loader.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2928 The name of this C&nbsp;function is the string "<code>luaopen_</code>"
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2929 concatenated with a copy of the module name where each dot
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2930 is replaced by an underscore.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2931 Moreover, if the module name has a hyphen,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2932 its prefix up to (and including) the first hyphen is removed.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2933 For instance, if the module name is <code>a.v1-b.c</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2934 the function name will be <code>luaopen_b_c</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2935
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2936
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2937 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2938 The fourth searcher tries an <em>all-in-one loader</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2939 It searches the C&nbsp;path for a library for
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2940 the root name of the given module.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2941 For instance, when requiring <code>a.b.c</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2942 it will search for a C&nbsp;library for <code>a</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2943 If found, it looks into it for an open function for
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2944 the submodule;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2945 in our example, that would be <code>luaopen_a_b_c</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2946 With this facility, a package can pack several C&nbsp;submodules
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2947 into one single library,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2948 with each submodule keeping its original open function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2949
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2950
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2951 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2952 All searchers except the first one (preload) return as the extra value
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2953 the file name where the module was found,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2954 as returned by <a href="#pdf-package.searchpath"><code>package.searchpath</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2955 The first searcher returns no extra value.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2956
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2957
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2958
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2959
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2960 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2961 <hr><h3><a name="pdf-package.searchpath"><code>package.searchpath (name, path [, sep [, rep]])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2962
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2963
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2964 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2965 Searches for the given <code>name</code> in the given <code>path</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2966
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2967
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2968 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2969 A path is a string containing a sequence of
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2970 <em>templates</em> separated by semicolons.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2971 For each template,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2972 the function replaces each interrogation mark (if any)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2973 in the template with a copy of <code>name</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2974 wherein all occurrences of <code>sep</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2975 (a dot, by default)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2976 were replaced by <code>rep</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2977 (the system's directory separator, by default),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2978 and then tries to open the resulting file name.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2979
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2980
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2981 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2982 For instance, if the path is the string
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2983
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2984 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2985 "./?.lua;./?.lc;/usr/local/?/init.lua"
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2986 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2987 the search for the name <code>foo.a</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2988 will try to open the files
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2989 <code>./foo/a.lua</code>, <code>./foo/a.lc</code>, and
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2990 <code>/usr/local/foo/a/init.lua</code>, in that order.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2991
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2992
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2993 <p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2994 Returns the resulting name of the first file that it can
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2995 open in read mode (after closing the file),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2996 or <b>nil</b> plus an error message if none succeeds.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2997 (This error message lists all file names it tried to open.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2998
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
2999
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3000
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3001
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3002
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3003
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3004
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3005 <h2>6.4 &ndash; <a name="6.4">String Manipulation</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3006
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3007 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3008 This library provides generic functions for string manipulation,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3009 such as finding and extracting substrings, and pattern matching.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3010 When indexing a string in Lua, the first character is at position&nbsp;1
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3011 (not at&nbsp;0, as in C).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3012 Indices are allowed to be negative and are interpreted as indexing backwards,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3013 from the end of the string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3014 Thus, the last character is at position -1, and so on.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3015
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3016
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3017 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3018 The string library provides all its functions inside the table
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3019 <a name="pdf-string"><code>string</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3020 It also sets a metatable for strings
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3021 where the <code>__index</code> field points to the <code>string</code> table.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3022 Therefore, you can use the string functions in object-oriented style.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3023 For instance, <code>string.byte(s,i)</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3024 can be written as <code>s:byte(i)</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3025
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3026
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3027 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3028 The string library assumes one-byte character encodings.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3029
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3030
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3031 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3032 <hr><h3><a name="pdf-string.byte"><code>string.byte (s [, i [, j]])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3033 Returns the internal numerical codes of the characters <code>s[i]</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3034 <code>s[i+1]</code>, ..., <code>s[j]</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3035 The default value for <code>i</code> is&nbsp;1;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3036 the default value for <code>j</code> is&nbsp;<code>i</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3037 These indices are corrected
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3038 following the same rules of function <a href="#pdf-string.sub"><code>string.sub</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3039
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3040
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3041 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3042 Numerical codes are not necessarily portable across platforms.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3043
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3044
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3045
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3046
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3047 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3048 <hr><h3><a name="pdf-string.char"><code>string.char (&middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3049 Receives zero or more integers.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3050 Returns a string with length equal to the number of arguments,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3051 in which each character has the internal numerical code equal
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3052 to its corresponding argument.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3053
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3054
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3055 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3056 Numerical codes are not necessarily portable across platforms.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3057
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3058
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3059
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3060
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3061 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3062 <hr><h3><a name="pdf-string.dump"><code>string.dump (function)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3063
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3064
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3065 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3066 Returns a string containing a binary representation of the given function,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3067 so that a later <a href="#pdf-load"><code>load</code></a> on this string returns
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3068 a copy of the function (but with new upvalues).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3069
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3070
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3071
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3072
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3073 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3074 <hr><h3><a name="pdf-string.find"><code>string.find (s, pattern [, init [, plain]])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3075
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3076
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3077 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3078 Looks for the first match of
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3079 <code>pattern</code> in the string <code>s</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3080 If it finds a match, then <code>find</code> returns the indices of&nbsp;<code>s</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3081 where this occurrence starts and ends;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3082 otherwise, it returns <b>nil</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3083 A third, optional numerical argument <code>init</code> specifies
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3084 where to start the search;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3085 its default value is&nbsp;1 and can be negative.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3086 A value of <b>true</b> as a fourth, optional argument <code>plain</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3087 turns off the pattern matching facilities,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3088 so the function does a plain "find substring" operation,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3089 with no characters in <code>pattern</code> being considered magic.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3090 Note that if <code>plain</code> is given, then <code>init</code> must be given as well.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3091
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3092
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3093 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3094 If the pattern has captures,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3095 then in a successful match
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3096 the captured values are also returned,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3097 after the two indices.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3098
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3099
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3100
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3101
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3102 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3103 <hr><h3><a name="pdf-string.format"><code>string.format (formatstring, &middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3104
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3105
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3106 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3107 Returns a formatted version of its variable number of arguments
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3108 following the description given in its first argument (which must be a string).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3109 The format string follows the same rules as the ANSI&nbsp;C function <code>sprintf</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3110 The only differences are that the options/modifiers
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3111 <code>*</code>, <code>h</code>, <code>L</code>, <code>l</code>, <code>n</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3112 and <code>p</code> are not supported
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3113 and that there is an extra option, <code>q</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3114 The <code>q</code> option formats a string between double quotes,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3115 using escape sequences when necessary to ensure that
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3116 it can safely be read back by the Lua interpreter.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3117 For instance, the call
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3118
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3119 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3120 string.format('%q', 'a string with "quotes" and \n new line')
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3121 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3122 may produce the string:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3123
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3124 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3125 "a string with \"quotes\" and \
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3126 new line"
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3127 </pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3128
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3129 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3130 Options
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3131 <code>A</code> and <code>a</code> (when available),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3132 <code>E</code>, <code>e</code>, <code>f</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3133 <code>G</code>, and <code>g</code> all expect a number as argument.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3134 Options <code>c</code>, <code>d</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3135 <code>i</code>, <code>o</code>, <code>u</code>, <code>X</code>, and <code>x</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3136 also expect a number,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3137 but the range of that number may be limited by
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3138 the underlying C&nbsp;implementation.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3139 For options <code>o</code>, <code>u</code>, <code>X</code>, and <code>x</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3140 the number cannot be negative.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3141 Option <code>q</code> expects a string;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3142 option <code>s</code> expects a string without embedded zeros.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3143 If the argument to option <code>s</code> is not a string,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3144 it is converted to one following the same rules of <a href="#pdf-tostring"><code>tostring</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3145
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3146
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3147
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3148
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3149 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3150 <hr><h3><a name="pdf-string.gmatch"><code>string.gmatch (s, pattern)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3151 Returns an iterator function that,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3152 each time it is called,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3153 returns the next captures from <code>pattern</code> over the string <code>s</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3154 If <code>pattern</code> specifies no captures,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3155 then the whole match is produced in each call.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3156
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3157
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3158 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3159 As an example, the following loop
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3160 will iterate over all the words from string <code>s</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3161 printing one per line:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3162
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3163 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3164 s = "hello world from Lua"
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3165 for w in string.gmatch(s, "%a+") do
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3166 print(w)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3167 end
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3168 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3169 The next example collects all pairs <code>key=value</code> from the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3170 given string into a table:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3171
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3172 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3173 t = {}
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3174 s = "from=world, to=Lua"
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3175 for k, v in string.gmatch(s, "(%w+)=(%w+)") do
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3176 t[k] = v
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3177 end
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3178 </pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3179
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3180 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3181 For this function, a caret '<code>^</code>' at the start of a pattern does not
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3182 work as an anchor, as this would prevent the iteration.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3183
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3184
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3185
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3186
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3187 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3188 <hr><h3><a name="pdf-string.gsub"><code>string.gsub (s, pattern, repl [, n])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3189 Returns a copy of <code>s</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3190 in which all (or the first <code>n</code>, if given)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3191 occurrences of the <code>pattern</code> have been
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3192 replaced by a replacement string specified by <code>repl</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3193 which can be a string, a table, or a function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3194 <code>gsub</code> also returns, as its second value,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3195 the total number of matches that occurred.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3196 The name <code>gsub</code> comes from <em>Global SUBstitution</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3197
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3198
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3199 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3200 If <code>repl</code> is a string, then its value is used for replacement.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3201 The character&nbsp;<code>%</code> works as an escape character:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3202 any sequence in <code>repl</code> of the form <code>%<em>d</em></code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3203 with <em>d</em> between 1 and 9,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3204 stands for the value of the <em>d</em>-th captured substring.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3205 The sequence <code>%0</code> stands for the whole match.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3206 The sequence <code>%%</code> stands for a single&nbsp;<code>%</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3207
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3208
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3209 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3210 If <code>repl</code> is a table, then the table is queried for every match,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3211 using the first capture as the key.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3212
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3213
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3214 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3215 If <code>repl</code> is a function, then this function is called every time a
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3216 match occurs, with all captured substrings passed as arguments,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3217 in order.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3218
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3219
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3220 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3221 In any case,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3222 if the pattern specifies no captures,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3223 then it behaves as if the whole pattern was inside a capture.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3224
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3225
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3226 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3227 If the value returned by the table query or by the function call
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3228 is a string or a number,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3229 then it is used as the replacement string;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3230 otherwise, if it is <b>false</b> or <b>nil</b>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3231 then there is no replacement
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3232 (that is, the original match is kept in the string).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3233
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3234
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3235 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3236 Here are some examples:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3237
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3238 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3239 x = string.gsub("hello world", "(%w+)", "%1 %1")
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3240 --&gt; x="hello hello world world"
242
b5a926c481a5 Handle first h1 tag differently.
hugo.tech@gmail.com <hugo.tech@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 241
diff changeset
3241
239
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3242 x = string.gsub("hello world", "%w+", "%0 %0", 1)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3243 --&gt; x="hello hello world"
242
b5a926c481a5 Handle first h1 tag differently.
hugo.tech@gmail.com <hugo.tech@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 241
diff changeset
3244
239
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3245 x = string.gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1")
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3246 --&gt; x="world hello Lua from"
242
b5a926c481a5 Handle first h1 tag differently.
hugo.tech@gmail.com <hugo.tech@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 241
diff changeset
3247
239
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3248 x = string.gsub("home = $HOME, user = $USER", "%$(%w+)", os.getenv)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3249 --&gt; x="home = /home/roberto, user = roberto"
242
b5a926c481a5 Handle first h1 tag differently.
hugo.tech@gmail.com <hugo.tech@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 241
diff changeset
3250
239
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3251 x = string.gsub("4+5 = $return 4+5$", "%$(.-)%$", function (s)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3252 return load(s)()
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3253 end)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3254 --&gt; x="4+5 = 9"
242
b5a926c481a5 Handle first h1 tag differently.
hugo.tech@gmail.com <hugo.tech@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 241
diff changeset
3255
239
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3256 local t = {name="lua", version="5.2"}
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3257 x = string.gsub("$name-$version.tar.gz", "%$(%w+)", t)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3258 --&gt; x="lua-5.2.tar.gz"
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3259 </pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3260
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3261
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3262
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3263 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3264 <hr><h3><a name="pdf-string.len"><code>string.len (s)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3265 Receives a string and returns its length.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3266 The empty string <code>""</code> has length 0.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3267 Embedded zeros are counted,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3268 so <code>"a\000bc\000"</code> has length 5.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3269
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3270
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3271
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3272
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3273 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3274 <hr><h3><a name="pdf-string.lower"><code>string.lower (s)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3275 Receives a string and returns a copy of this string with all
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3276 uppercase letters changed to lowercase.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3277 All other characters are left unchanged.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3278 The definition of what an uppercase letter is depends on the current locale.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3279
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3280
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3281
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3282
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3283 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3284 <hr><h3><a name="pdf-string.match"><code>string.match (s, pattern [, init])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3285 Looks for the first <em>match</em> of
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3286 <code>pattern</code> in the string <code>s</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3287 If it finds one, then <code>match</code> returns
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3288 the captures from the pattern;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3289 otherwise it returns <b>nil</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3290 If <code>pattern</code> specifies no captures,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3291 then the whole match is returned.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3292 A third, optional numerical argument <code>init</code> specifies
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3293 where to start the search;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3294 its default value is&nbsp;1 and can be negative.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3295
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3296
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3297
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3298
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3299 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3300 <hr><h3><a name="pdf-string.rep"><code>string.rep (s, n [, sep])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3301 Returns a string that is the concatenation of <code>n</code> copies of
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3302 the string <code>s</code> separated by the string <code>sep</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3303 The default value for <code>sep</code> is the empty string
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3304 (that is, no separator).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3305
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3306
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3307
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3308
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3309 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3310 <hr><h3><a name="pdf-string.reverse"><code>string.reverse (s)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3311 Returns a string that is the string <code>s</code> reversed.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3312
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3313
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3314
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3315
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3316 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3317 <hr><h3><a name="pdf-string.sub"><code>string.sub (s, i [, j])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3318 Returns the substring of <code>s</code> that
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3319 starts at <code>i</code> and continues until <code>j</code>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3320 <code>i</code> and <code>j</code> can be negative.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3321 If <code>j</code> is absent, then it is assumed to be equal to -1
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3322 (which is the same as the string length).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3323 In particular,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3324 the call <code>string.sub(s,1,j)</code> returns a prefix of <code>s</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3325 with length <code>j</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3326 and <code>string.sub(s, -i)</code> returns a suffix of <code>s</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3327 with length <code>i</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3328
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3329
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3330 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3331 If, after the translation of negative indices,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3332 <code>i</code> is less than 1,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3333 it is corrected to 1.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3334 If <code>j</code> is greater than the string length,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3335 it is corrected to that length.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3336 If, after these corrections,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3337 <code>i</code> is greater than <code>j</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3338 the function returns the empty string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3339
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3340
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3341
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3342
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3343 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3344 <hr><h3><a name="pdf-string.upper"><code>string.upper (s)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3345 Receives a string and returns a copy of this string with all
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3346 lowercase letters changed to uppercase.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3347 All other characters are left unchanged.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3348 The definition of what a lowercase letter is depends on the current locale.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3349
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3350
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3351
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3352 <h3>6.4.1 &ndash; <a name="6.4.1">Patterns</a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3353
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3354
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3355 <h4>Character Class:</h4><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3356 A <em>character class</em> is used to represent a set of characters.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3357 The following combinations are allowed in describing a character class:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3358
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3359 <ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3360
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3361 <li><b><em>x</em>: </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3362 (where <em>x</em> is not one of the <em>magic characters</em>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3363 <code>^$()%.[]*+-?</code>)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3364 represents the character <em>x</em> itself.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3365 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3366
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3367 <li><b><code>.</code>: </b> (a dot) represents all characters.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3368
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3369 <li><b><code>%a</code>: </b> represents all letters.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3370
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3371 <li><b><code>%c</code>: </b> represents all control characters.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3372
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3373 <li><b><code>%d</code>: </b> represents all digits.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3374
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3375 <li><b><code>%g</code>: </b> represents all printable characters except space.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3376
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3377 <li><b><code>%l</code>: </b> represents all lowercase letters.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3378
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3379 <li><b><code>%p</code>: </b> represents all punctuation characters.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3380
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3381 <li><b><code>%s</code>: </b> represents all space characters.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3382
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3383 <li><b><code>%u</code>: </b> represents all uppercase letters.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3384
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3385 <li><b><code>%w</code>: </b> represents all alphanumeric characters.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3386
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3387 <li><b><code>%x</code>: </b> represents all hexadecimal digits.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3388
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3389 <li><b><code>%<em>x</em></code>: </b> (where <em>x</em> is any non-alphanumeric character)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3390 represents the character <em>x</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3391 This is the standard way to escape the magic characters.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3392 Any punctuation character (even the non magic)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3393 can be preceded by a '<code>%</code>'
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3394 when used to represent itself in a pattern.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3395 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3396
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3397 <li><b><code>[<em>set</em>]</code>: </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3398 represents the class which is the union of all
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3399 characters in <em>set</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3400 A range of characters can be specified by
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3401 separating the end characters of the range,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3402 in ascending order, with a '<code>-</code>',
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3403 All classes <code>%</code><em>x</em> described above can also be used as
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3404 components in <em>set</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3405 All other characters in <em>set</em> represent themselves.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3406 For example, <code>[%w_]</code> (or <code>[_%w]</code>)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3407 represents all alphanumeric characters plus the underscore,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3408 <code>[0-7]</code> represents the octal digits,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3409 and <code>[0-7%l%-]</code> represents the octal digits plus
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3410 the lowercase letters plus the '<code>-</code>' character.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3411
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3412
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3413 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3414 The interaction between ranges and classes is not defined.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3415 Therefore, patterns like <code>[%a-z]</code> or <code>[a-%%]</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3416 have no meaning.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3417 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3418
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3419 <li><b><code>[^<em>set</em>]</code>: </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3420 represents the complement of <em>set</em>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3421 where <em>set</em> is interpreted as above.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3422 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3423
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3424 </ul><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3425 For all classes represented by single letters (<code>%a</code>, <code>%c</code>, etc.),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3426 the corresponding uppercase letter represents the complement of the class.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3427 For instance, <code>%S</code> represents all non-space characters.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3428
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3429
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3430 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3431 The definitions of letter, space, and other character groups
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3432 depend on the current locale.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3433 In particular, the class <code>[a-z]</code> may not be equivalent to <code>%l</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3434
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3435
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3436
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3437
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3438
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3439 <h4>Pattern Item:</h4><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3440 A <em>pattern item</em> can be
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3441
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3442 <ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3443
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3444 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3445 a single character class,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3446 which matches any single character in the class;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3447 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3448
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3449 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3450 a single character class followed by '<code>*</code>',
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3451 which matches 0 or more repetitions of characters in the class.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3452 These repetition items will always match the longest possible sequence;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3453 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3454
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3455 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3456 a single character class followed by '<code>+</code>',
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3457 which matches 1 or more repetitions of characters in the class.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3458 These repetition items will always match the longest possible sequence;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3459 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3460
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3461 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3462 a single character class followed by '<code>-</code>',
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3463 which also matches 0 or more repetitions of characters in the class.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3464 Unlike '<code>*</code>',
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3465 these repetition items will always match the shortest possible sequence;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3466 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3467
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3468 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3469 a single character class followed by '<code>?</code>',
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3470 which matches 0 or 1 occurrence of a character in the class;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3471 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3472
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3473 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3474 <code>%<em>n</em></code>, for <em>n</em> between 1 and 9;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3475 such item matches a substring equal to the <em>n</em>-th captured string
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3476 (see below);
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3477 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3478
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3479 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3480 <code>%b<em>xy</em></code>, where <em>x</em> and <em>y</em> are two distinct characters;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3481 such item matches strings that start with&nbsp;<em>x</em>, end with&nbsp;<em>y</em>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3482 and where the <em>x</em> and <em>y</em> are <em>balanced</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3483 This means that, if one reads the string from left to right,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3484 counting <em>+1</em> for an <em>x</em> and <em>-1</em> for a <em>y</em>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3485 the ending <em>y</em> is the first <em>y</em> where the count reaches 0.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3486 For instance, the item <code>%b()</code> matches expressions with
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3487 balanced parentheses.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3488 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3489
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3490 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3491 <code>%f[<em>set</em>]</code>, a <em>frontier pattern</em>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3492 such item matches an empty string at any position such that
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3493 the next character belongs to <em>set</em>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3494 and the previous character does not belong to <em>set</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3495 The set <em>set</em> is interpreted as previously described.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3496 The beginning and the end of the subject are handled as if
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3497 they were the character '<code>\0</code>'.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3498 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3499
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3500 </ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3501
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3502
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3503
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3504
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3505 <h4>Pattern:</h4><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3506 A <em>pattern</em> is a sequence of pattern items.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3507 A caret '<code>^</code>' at the beginning of a pattern anchors the match at the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3508 beginning of the subject string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3509 A '<code>$</code>' at the end of a pattern anchors the match at the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3510 end of the subject string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3511 At other positions,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3512 '<code>^</code>' and '<code>$</code>' have no special meaning and represent themselves.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3513
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3514
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3515
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3516
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3517
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3518 <h4>Captures:</h4><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3519 A pattern can contain sub-patterns enclosed in parentheses;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3520 they describe <em>captures</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3521 When a match succeeds, the substrings of the subject string
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3522 that match captures are stored (<em>captured</em>) for future use.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3523 Captures are numbered according to their left parentheses.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3524 For instance, in the pattern <code>"(a*(.)%w(%s*))"</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3525 the part of the string matching <code>"a*(.)%w(%s*)"</code> is
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3526 stored as the first capture (and therefore has number&nbsp;1);
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3527 the character matching "<code>.</code>" is captured with number&nbsp;2,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3528 and the part matching "<code>%s*</code>" has number&nbsp;3.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3529
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3530
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3531 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3532 As a special case, the empty capture <code>()</code> captures
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3533 the current string position (a number).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3534 For instance, if we apply the pattern <code>"()aa()"</code> on the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3535 string <code>"flaaap"</code>, there will be two captures: 3&nbsp;and&nbsp;5.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3536
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3537
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3538
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3539
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3540
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3541
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3542
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3543
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3544
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3545
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3546
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3547 <h2>6.5 &ndash; <a name="6.5">Table Manipulation</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3548
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3549 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3550 This library provides generic functions for table manipulation.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3551 It provides all its functions inside the table <a name="pdf-table"><code>table</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3552
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3553
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3554 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3555 Remember that, whenever an operation needs the length of a table,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3556 the table should be a proper sequence
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3557 or have a <code>__len</code> metamethod (see <a href="#3.4.6">&sect;3.4.6</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3558 All functions ignore non-numeric keys
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3559 in tables given as arguments.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3560
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3561
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3562 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3563 For performance reasons,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3564 all table accesses (get/set) performed by these functions are raw.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3565
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3566
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3567 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3568 <hr><h3><a name="pdf-table.concat"><code>table.concat (list [, sep [, i [, j]]])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3569
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3570
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3571 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3572 Given a list where all elements are strings or numbers,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3573 returns the string <code>list[i]..sep..list[i+1] &middot;&middot;&middot; sep..list[j]</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3574 The default value for <code>sep</code> is the empty string,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3575 the default for <code>i</code> is 1,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3576 and the default for <code>j</code> is <code>#list</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3577 If <code>i</code> is greater than <code>j</code>, returns the empty string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3578
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3579
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3580
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3581
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3582 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3583 <hr><h3><a name="pdf-table.insert"><code>table.insert (list, [pos,] value)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3584
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3585
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3586 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3587 Inserts element <code>value</code> at position <code>pos</code> in <code>list</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3588 shifting up the elements
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3589 <code>list[pos], list[pos+1], &middot;&middot;&middot;, list[#list]</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3590 The default value for <code>pos</code> is <code>#list+1</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3591 so that a call <code>table.insert(t,x)</code> inserts <code>x</code> at the end
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3592 of list <code>t</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3593
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3594
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3595
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3596
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3597 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3598 <hr><h3><a name="pdf-table.pack"><code>table.pack (&middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3599
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3600
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3601 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3602 Returns a new table with all parameters stored into keys 1, 2, etc.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3603 and with a field "<code>n</code>" with the total number of parameters.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3604 Note that the resulting table may not be a sequence.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3605
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3606
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3607
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3608
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3609 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3610 <hr><h3><a name="pdf-table.remove"><code>table.remove (list [, pos])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3611
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3612
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3613 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3614 Removes from <code>list</code> the element at position <code>pos</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3615 returning the value of the removed element.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3616 When <code>pos</code> is an integer between 1 and <code>#list</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3617 it shifts down the elements
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3618 <code>list[pos+1], list[pos+2], &middot;&middot;&middot;, list[#list]</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3619 and erases element <code>list[#list]</code>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3620 The index <code>pos</code> can also be 0 when <code>#list</code> is 0,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3621 or <code>#list + 1</code>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3622 in those cases, the function erases the element <code>list[pos]</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3623
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3624
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3625 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3626 The default value for <code>pos</code> is <code>#list</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3627 so that a call <code>table.remove(t)</code> removes the last element
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3628 of list <code>t</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3629
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3630
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3631
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3632
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3633 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3634 <hr><h3><a name="pdf-table.sort"><code>table.sort (list [, comp])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3635
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3636
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3637 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3638 Sorts list elements in a given order, <em>in-place</em>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3639 from <code>list[1]</code> to <code>list[#list]</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3640 If <code>comp</code> is given,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3641 then it must be a function that receives two list elements
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3642 and returns true when the first element must come
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3643 before the second in the final order
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3644 (so that <code>not comp(list[i+1],list[i])</code> will be true after the sort).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3645 If <code>comp</code> is not given,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3646 then the standard Lua operator <code>&lt;</code> is used instead.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3647
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3648
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3649 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3650 The sort algorithm is not stable;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3651 that is, elements considered equal by the given order
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3652 may have their relative positions changed by the sort.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3653
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3654
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3655
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3656
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3657 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3658 <hr><h3><a name="pdf-table.unpack"><code>table.unpack (list [, i [, j]])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3659
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3660
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3661 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3662 Returns the elements from the given table.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3663 This function is equivalent to
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3664
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3665 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3666 return list[i], list[i+1], &middot;&middot;&middot;, list[j]
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3667 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3668 By default, <code>i</code> is&nbsp;1 and <code>j</code> is <code>#list</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3669
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3670
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3671
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3672
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3673
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3674
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3675
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3676 <h2>6.6 &ndash; <a name="6.6">Mathematical Functions</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3677
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3678 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3679 This library is an interface to the standard C&nbsp;math library.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3680 It provides all its functions inside the table <a name="pdf-math"><code>math</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3681
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3682
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3683 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3684 <hr><h3><a name="pdf-math.abs"><code>math.abs (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3685
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3686
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3687 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3688 Returns the absolute value of <code>x</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3689
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3690
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3691
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3692
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3693 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3694 <hr><h3><a name="pdf-math.acos"><code>math.acos (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3695
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3696
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3697 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3698 Returns the arc cosine of <code>x</code> (in radians).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3699
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3700
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3701
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3702
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3703 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3704 <hr><h3><a name="pdf-math.asin"><code>math.asin (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3705
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3706
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3707 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3708 Returns the arc sine of <code>x</code> (in radians).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3709
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3710
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3711
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3712
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3713 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3714 <hr><h3><a name="pdf-math.atan"><code>math.atan (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3715
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3716
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3717 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3718 Returns the arc tangent of <code>x</code> (in radians).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3719
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3720
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3721
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3722
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3723 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3724 <hr><h3><a name="pdf-math.atan2"><code>math.atan2 (y, x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3725
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3726
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3727 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3728 Returns the arc tangent of <code>y/x</code> (in radians),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3729 but uses the signs of both parameters to find the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3730 quadrant of the result.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3731 (It also handles correctly the case of <code>x</code> being zero.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3732
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3733
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3734
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3735
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3736 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3737 <hr><h3><a name="pdf-math.ceil"><code>math.ceil (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3738
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
3739
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3740 <p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3741 Returns the smallest integer larger than or equal to <code>x</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3742
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3743
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3744
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3745
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3746 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3747 <hr><h3><a name="pdf-math.cos"><code>math.cos (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3748
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3749
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3750 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3751 Returns the cosine of <code>x</code> (assumed to be in radians).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3752
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3753
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3754
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3755
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3756 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3757 <hr><h3><a name="pdf-math.cosh"><code>math.cosh (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3758
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3759
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3760 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3761 Returns the hyperbolic cosine of <code>x</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3762
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3763
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3764
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3765
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3766 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3767 <hr><h3><a name="pdf-math.deg"><code>math.deg (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3768
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3769
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3770 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3771 Returns the angle <code>x</code> (given in radians) in degrees.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3772
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3773
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3774
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3775
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3776 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3777 <hr><h3><a name="pdf-math.exp"><code>math.exp (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3778
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3779
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3780 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3781 Returns the value <em>e<sup>x</sup></em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3782
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3783
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3784
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3785
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3786 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3787 <hr><h3><a name="pdf-math.floor"><code>math.floor (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3788
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3789
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3790 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3791 Returns the largest integer smaller than or equal to <code>x</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3792
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3793
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3794
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3795
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3796 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3797 <hr><h3><a name="pdf-math.fmod"><code>math.fmod (x, y)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3798
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3799
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3800 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3801 Returns the remainder of the division of <code>x</code> by <code>y</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3802 that rounds the quotient towards zero.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3803
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3804
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3805
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3806
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3807 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3808 <hr><h3><a name="pdf-math.frexp"><code>math.frexp (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3809
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3810
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3811 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3812 Returns <code>m</code> and <code>e</code> such that <em>x = m2<sup>e</sup></em>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3813 <code>e</code> is an integer and the absolute value of <code>m</code> is
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3814 in the range <em>[0.5, 1)</em>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3815 (or zero when <code>x</code> is zero).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3816
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3817
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3818
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3819
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3820 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3821 <hr><h3><a name="pdf-math.huge"><code>math.huge</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3822
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3823
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3824 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3825 The value <code>HUGE_VAL</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3826 a value larger than or equal to any other numerical value.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3827
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3828
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3829
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3830
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3831 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3832 <hr><h3><a name="pdf-math.ldexp"><code>math.ldexp (m, e)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3833
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3834
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3835 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3836 Returns <em>m2<sup>e</sup></em> (<code>e</code> should be an integer).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3837
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3838
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3839
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3840
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3841 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3842 <hr><h3><a name="pdf-math.log"><code>math.log (x [, base])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3843
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3844
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3845 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3846 Returns the logarithm of <code>x</code> in the given base.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3847 The default for <code>base</code> is <em>e</em>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3848 (so that the function returns the natural logarithm of <code>x</code>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3849
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3850
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3851
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3852
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3853 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3854 <hr><h3><a name="pdf-math.max"><code>math.max (x, &middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3855
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3856
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3857 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3858 Returns the maximum value among its arguments.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3859
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3860
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3861
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3862
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3863 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3864 <hr><h3><a name="pdf-math.min"><code>math.min (x, &middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3865
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3866
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3867 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3868 Returns the minimum value among its arguments.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3869
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3870
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3871
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3872
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3873 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3874 <hr><h3><a name="pdf-math.modf"><code>math.modf (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3875
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3876
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3877 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3878 Returns two numbers,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3879 the integral part of <code>x</code> and the fractional part of <code>x</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3880
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3881
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3882
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3883
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3884 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3885 <hr><h3><a name="pdf-math.pi"><code>math.pi</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3886
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3887
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3888 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3889 The value of <em>&pi;</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3890
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3891
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3892
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3893
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3894 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3895 <hr><h3><a name="pdf-math.pow"><code>math.pow (x, y)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3896
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3897
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3898 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3899 Returns <em>x<sup>y</sup></em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3900 (You can also use the expression <code>x^y</code> to compute this value.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3901
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3902
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3903
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3904
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3905 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3906 <hr><h3><a name="pdf-math.rad"><code>math.rad (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3907
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3908
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3909 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3910 Returns the angle <code>x</code> (given in degrees) in radians.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3911
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3912
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3913
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3914
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3915 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3916 <hr><h3><a name="pdf-math.random"><code>math.random ([m [, n]])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3917
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3918
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3919 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3920 This function is an interface to the simple
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3921 pseudo-random generator function <code>rand</code> provided by Standard&nbsp;C.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3922 (No guarantees can be given for its statistical properties.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3923
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3924
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3925 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3926 When called without arguments,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3927 returns a uniform pseudo-random real number
242
b5a926c481a5 Handle first h1 tag differently.
hugo.tech@gmail.com <hugo.tech@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 241
diff changeset
3928 in the range <em>[0,1)</em>.
239
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3929 When called with an integer number <code>m</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3930 <code>math.random</code> returns
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3931 a uniform pseudo-random integer in the range <em>[1, m]</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3932 When called with two integer numbers <code>m</code> and <code>n</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3933 <code>math.random</code> returns a uniform pseudo-random
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3934 integer in the range <em>[m, n]</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3935
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3936
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3937
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3938
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3939 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3940 <hr><h3><a name="pdf-math.randomseed"><code>math.randomseed (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3941
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3942
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3943 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3944 Sets <code>x</code> as the "seed"
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3945 for the pseudo-random generator:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3946 equal seeds produce equal sequences of numbers.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3947
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3948
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3949
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3950
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3951 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3952 <hr><h3><a name="pdf-math.sin"><code>math.sin (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3953
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3954
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3955 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3956 Returns the sine of <code>x</code> (assumed to be in radians).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3957
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3958
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3959
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3960
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3961 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3962 <hr><h3><a name="pdf-math.sinh"><code>math.sinh (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3963
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3964
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3965 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3966 Returns the hyperbolic sine of <code>x</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3967
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3968
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3969
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3970
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3971 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3972 <hr><h3><a name="pdf-math.sqrt"><code>math.sqrt (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3973
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3974
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3975 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3976 Returns the square root of <code>x</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3977 (You can also use the expression <code>x^0.5</code> to compute this value.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3978
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3979
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3980
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3981
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3982 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3983 <hr><h3><a name="pdf-math.tan"><code>math.tan (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3984
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3985
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3986 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3987 Returns the tangent of <code>x</code> (assumed to be in radians).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3988
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3989
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3990
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3991
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3992 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3993 <hr><h3><a name="pdf-math.tanh"><code>math.tanh (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3994
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3995
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3996 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3997 Returns the hyperbolic tangent of <code>x</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3998
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
3999
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4000
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parents:
diff changeset
4001
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4002
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4003
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4004
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4005 <h2>6.7 &ndash; <a name="6.7">Bitwise Operations</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4006
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4007 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4008 This library provides bitwise operations.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4009 It provides all its functions inside the table <a name="pdf-bit32"><code>bit32</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4010
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parents:
diff changeset
4011
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4012 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4013 Unless otherwise stated,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4014 all functions accept numeric arguments in the range
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4015 <em>(-2<sup>51</sup>,+2<sup>51</sup>)</em>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4016 each argument is normalized to
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4017 the remainder of its division by <em>2<sup>32</sup></em>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4018 and truncated to an integer (in some unspecified way),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4019 so that its final value falls in the range <em>[0,2<sup>32</sup> - 1]</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4020 Similarly, all results are in the range <em>[0,2<sup>32</sup> - 1]</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4021 Note that <code>bit32.bnot(0)</code> is <code>0xFFFFFFFF</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4022 which is different from <code>-1</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4023
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parents:
diff changeset
4024
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4025 <p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4026 <hr><h3><a name="pdf-bit32.arshift"><code>bit32.arshift (x, disp)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4027
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4028
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4029 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4030 Returns the number <code>x</code> shifted <code>disp</code> bits to the right.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4031 The number <code>disp</code> may be any representable integer.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4032 Negative displacements shift to the left.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4033
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parents:
diff changeset
4034
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4035 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4036 This shift operation is what is called arithmetic shift.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4037 Vacant bits on the left are filled
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4038 with copies of the higher bit of <code>x</code>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4039 vacant bits on the right are filled with zeros.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4040 In particular,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4041 displacements with absolute values higher than 31
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4042 result in zero or <code>0xFFFFFFFF</code> (all original bits are shifted out).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4043
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4044
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4045
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4046
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4047 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4048 <hr><h3><a name="pdf-bit32.band"><code>bit32.band (&middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4049
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4050
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4051 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4052 Returns the bitwise <em>and</em> of its operands.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4053
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4054
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4055
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4056
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4057 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4058 <hr><h3><a name="pdf-bit32.bnot"><code>bit32.bnot (x)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4059
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4060
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4061 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4062 Returns the bitwise negation of <code>x</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4063 For any integer <code>x</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4064 the following identity holds:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4065
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4066 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4067 assert(bit32.bnot(x) == (-1 - x) % 2^32)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4068 </pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4069
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4070
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4071
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4072 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4073 <hr><h3><a name="pdf-bit32.bor"><code>bit32.bor (&middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4074
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4075
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4076 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4077 Returns the bitwise <em>or</em> of its operands.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4078
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4079
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4080
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4081
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4082 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4083 <hr><h3><a name="pdf-bit32.btest"><code>bit32.btest (&middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4084
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4085
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4086 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4087 Returns a boolean signaling
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4088 whether the bitwise <em>and</em> of its operands is different from zero.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4089
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4090
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4091
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4092
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4093 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4094 <hr><h3><a name="pdf-bit32.bxor"><code>bit32.bxor (&middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4095
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parents:
diff changeset
4096
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4097 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4098 Returns the bitwise <em>exclusive or</em> of its operands.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4099
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4100
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4101
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4102
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4103 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4104 <hr><h3><a name="pdf-bit32.extract"><code>bit32.extract (n, field [, width])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4105
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4106
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4107 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4108 Returns the unsigned number formed by the bits
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4109 <code>field</code> to <code>field + width - 1</code> from <code>n</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4110 Bits are numbered from 0 (least significant) to 31 (most significant).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4111 All accessed bits must be in the range <em>[0, 31]</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4112
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4113
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4114 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4115 The default for <code>width</code> is 1.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4116
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4117
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4118
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4119
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4120 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4121 <hr><h3><a name="pdf-bit32.replace"><code>bit32.replace (n, v, field [, width])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4122
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4123
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4124 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4125 Returns a copy of <code>n</code> with
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4126 the bits <code>field</code> to <code>field + width - 1</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4127 replaced by the value <code>v</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4128 See <a href="#pdf-bit32.extract"><code>bit32.extract</code></a> for details about <code>field</code> and <code>width</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4129
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4130
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4131
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4132
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4133 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4134 <hr><h3><a name="pdf-bit32.lrotate"><code>bit32.lrotate (x, disp)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4135
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4136
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4137 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4138 Returns the number <code>x</code> rotated <code>disp</code> bits to the left.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4139 The number <code>disp</code> may be any representable integer.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4140
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4141
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4142 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4143 For any valid displacement,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4144 the following identity holds:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4145
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4146 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4147 assert(bit32.lrotate(x, disp) == bit32.lrotate(x, disp % 32))
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4148 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4149 In particular,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4150 negative displacements rotate to the right.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4151
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4152
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4153
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4154
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4155 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4156 <hr><h3><a name="pdf-bit32.lshift"><code>bit32.lshift (x, disp)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4157
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4158
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4159 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4160 Returns the number <code>x</code> shifted <code>disp</code> bits to the left.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4161 The number <code>disp</code> may be any representable integer.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4162 Negative displacements shift to the right.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4163 In any direction, vacant bits are filled with zeros.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4164 In particular,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4165 displacements with absolute values higher than 31
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4166 result in zero (all bits are shifted out).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4167
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4168
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4169 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4170 For positive displacements,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4171 the following equality holds:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4172
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4173 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4174 assert(bit32.lshift(b, disp) == (b * 2^disp) % 2^32)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4175 </pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4176
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4177
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4178
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4179 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4180 <hr><h3><a name="pdf-bit32.rrotate"><code>bit32.rrotate (x, disp)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4181
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4182
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4183 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4184 Returns the number <code>x</code> rotated <code>disp</code> bits to the right.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4185 The number <code>disp</code> may be any representable integer.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4186
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4187
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4188 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4189 For any valid displacement,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4190 the following identity holds:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4191
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4192 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4193 assert(bit32.rrotate(x, disp) == bit32.rrotate(x, disp % 32))
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4194 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4195 In particular,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4196 negative displacements rotate to the left.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4197
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4198
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4199
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4200
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4201 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4202 <hr><h3><a name="pdf-bit32.rshift"><code>bit32.rshift (x, disp)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4203
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4204
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4205 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4206 Returns the number <code>x</code> shifted <code>disp</code> bits to the right.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4207 The number <code>disp</code> may be any representable integer.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4208 Negative displacements shift to the left.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4209 In any direction, vacant bits are filled with zeros.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4210 In particular,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4211 displacements with absolute values higher than 31
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4212 result in zero (all bits are shifted out).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4213
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4214
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4215 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4216 For positive displacements,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4217 the following equality holds:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4218
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4219 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4220 assert(bit32.rshift(b, disp) == math.floor(b % 2^32 / 2^disp))
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4221 </pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4222
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4223 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4224 This shift operation is what is called logical shift.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4225
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4226
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4227
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4228
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4229
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4230
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4231
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4232 <h2>6.8 &ndash; <a name="6.8">Input and Output Facilities</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4233
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4234 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4235 The I/O library provides two different styles for file manipulation.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4236 The first one uses implicit file descriptors;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4237 that is, there are operations to set a default input file and a
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4238 default output file,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4239 and all input/output operations are over these default files.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4240 The second style uses explicit file descriptors.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4241
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4242
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4243 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4244 When using implicit file descriptors,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4245 all operations are supplied by table <a name="pdf-io"><code>io</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4246 When using explicit file descriptors,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4247 the operation <a href="#pdf-io.open"><code>io.open</code></a> returns a file descriptor
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4248 and then all operations are supplied as methods of the file descriptor.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4249
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4250
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4251 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4252 The table <code>io</code> also provides
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4253 three predefined file descriptors with their usual meanings from C:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4254 <a name="pdf-io.stdin"><code>io.stdin</code></a>, <a name="pdf-io.stdout"><code>io.stdout</code></a>, and <a name="pdf-io.stderr"><code>io.stderr</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4255 The I/O library never closes these files.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4256
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4257
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4258 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4259 Unless otherwise stated,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4260 all I/O functions return <b>nil</b> on failure
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4261 (plus an error message as a second result and
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4262 a system-dependent error code as a third result)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4263 and some value different from <b>nil</b> on success.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4264 On non-Posix systems,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4265 the computation of the error message and error code
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4266 in case of errors
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4267 may be not thread safe,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4268 because they rely on the global C variable <code>errno</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4269
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4270
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4271 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4272 <hr><h3><a name="pdf-io.close"><code>io.close ([file])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4273
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4274
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4275 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4276 Equivalent to <code>file:close()</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4277 Without a <code>file</code>, closes the default output file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4278
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4279
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4280
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4281
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4282 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4283 <hr><h3><a name="pdf-io.flush"><code>io.flush ()</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4284
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4285
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4286 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4287 Equivalent to <code>io.output():flush()</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4288
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4289
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4290
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4291
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4292 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4293 <hr><h3><a name="pdf-io.input"><code>io.input ([file])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4294
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4295
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4296 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4297 When called with a file name, it opens the named file (in text mode),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4298 and sets its handle as the default input file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4299 When called with a file handle,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4300 it simply sets this file handle as the default input file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4301 When called without parameters,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4302 it returns the current default input file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4303
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4304
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4305 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4306 In case of errors this function raises the error,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4307 instead of returning an error code.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4308
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4309
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4310
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4311
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4312 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4313 <hr><h3><a name="pdf-io.lines"><code>io.lines ([filename &middot;&middot;&middot;])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4314
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4315
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4316 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4317 Opens the given file name in read mode
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4318 and returns an iterator function that
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4319 works like <code>file:lines(&middot;&middot;&middot;)</code> over the opened file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4320 When the iterator function detects the end of file,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4321 it returns <b>nil</b> (to finish the loop) and automatically closes the file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4322
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4323
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4324 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4325 The call <code>io.lines()</code> (with no file name) is equivalent
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4326 to <code>io.input():lines()</code>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4327 that is, it iterates over the lines of the default input file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4328 In this case it does not close the file when the loop ends.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4329
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4330
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4331 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4332 In case of errors this function raises the error,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4333 instead of returning an error code.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4334
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4335
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4336
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4337
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4338 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4339 <hr><h3><a name="pdf-io.open"><code>io.open (filename [, mode])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4340
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4341
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4342 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4343 This function opens a file,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4344 in the mode specified in the string <code>mode</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4345 It returns a new file handle,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4346 or, in case of errors, <b>nil</b> plus an error message.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4347
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4348
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4349 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4350 The <code>mode</code> string can be any of the following:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4351
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4352 <ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4353 <li><b>"<code>r</code>": </b> read mode (the default);</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4354 <li><b>"<code>w</code>": </b> write mode;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4355 <li><b>"<code>a</code>": </b> append mode;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4356 <li><b>"<code>r+</code>": </b> update mode, all previous data is preserved;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4357 <li><b>"<code>w+</code>": </b> update mode, all previous data is erased;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4358 <li><b>"<code>a+</code>": </b> append update mode, previous data is preserved,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4359 writing is only allowed at the end of file.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4360 </ul><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4361 The <code>mode</code> string can also have a '<code>b</code>' at the end,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4362 which is needed in some systems to open the file in binary mode.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4363
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4364
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4365
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4366
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4367 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4368 <hr><h3><a name="pdf-io.output"><code>io.output ([file])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4369
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4370
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4371 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4372 Similar to <a href="#pdf-io.input"><code>io.input</code></a>, but operates over the default output file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4373
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4374
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4375
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4376
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4377 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4378 <hr><h3><a name="pdf-io.popen"><code>io.popen (prog [, mode])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4379
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4380
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4381 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4382 This function is system dependent and is not available
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4383 on all platforms.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4384
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4385
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4386 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4387 Starts program <code>prog</code> in a separated process and returns
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4388 a file handle that you can use to read data from this program
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4389 (if <code>mode</code> is <code>"r"</code>, the default)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4390 or to write data to this program
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4391 (if <code>mode</code> is <code>"w"</code>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4392
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4393
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4394
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4395
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4396 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4397 <hr><h3><a name="pdf-io.read"><code>io.read (&middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4398
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4399
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4400 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4401 Equivalent to <code>io.input():read(&middot;&middot;&middot;)</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4402
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4403
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4404
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4405
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4406 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4407 <hr><h3><a name="pdf-io.tmpfile"><code>io.tmpfile ()</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4408
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4409
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4410 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4411 Returns a handle for a temporary file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4412 This file is opened in update mode
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4413 and it is automatically removed when the program ends.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4414
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4415
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4416
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4417
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4418 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4419 <hr><h3><a name="pdf-io.type"><code>io.type (obj)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4420
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4421
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4422 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4423 Checks whether <code>obj</code> is a valid file handle.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4424 Returns the string <code>"file"</code> if <code>obj</code> is an open file handle,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4425 <code>"closed file"</code> if <code>obj</code> is a closed file handle,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4426 or <b>nil</b> if <code>obj</code> is not a file handle.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4427
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4428
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4429
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4430
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4431 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4432 <hr><h3><a name="pdf-io.write"><code>io.write (&middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4433
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4434
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4435 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4436 Equivalent to <code>io.output():write(&middot;&middot;&middot;)</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4437
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4438
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4439
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4440
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4441 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4442 <hr><h3><a name="pdf-file:close"><code>file:close ()</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4443
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4444
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4445 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4446 Closes <code>file</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4447 Note that files are automatically closed when
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4448 their handles are garbage collected,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4449 but that takes an unpredictable amount of time to happen.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4450
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4451
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4452 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4453 When closing a file handle created with <a href="#pdf-io.popen"><code>io.popen</code></a>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4454 <a href="#pdf-file:close"><code>file:close</code></a> returns the same values
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4455 returned by <a href="#pdf-os.execute"><code>os.execute</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4456
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4457
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4458
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4459
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4460 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4461 <hr><h3><a name="pdf-file:flush"><code>file:flush ()</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4462
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4463
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4464 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4465 Saves any written data to <code>file</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4466
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4467
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4468
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4469
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4470 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4471 <hr><h3><a name="pdf-file:lines"><code>file:lines (&middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4472
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4473
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4474 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4475 Returns an iterator function that,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4476 each time it is called,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4477 reads the file according to the given formats.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4478 When no format is given,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4479 uses "*l" as a default.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4480 As an example, the construction
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4481
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4482 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4483 for c in file:lines(1) do <em>body</em> end
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4484 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4485 will iterate over all characters of the file,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4486 starting at the current position.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4487 Unlike <a href="#pdf-io.lines"><code>io.lines</code></a>, this function does not close the file
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4488 when the loop ends.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4489
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4490
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4491 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4492 In case of errors this function raises the error,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4493 instead of returning an error code.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4494
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4495
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4496
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4497
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4498 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4499 <hr><h3><a name="pdf-file:read"><code>file:read (&middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4500
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4501
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4502 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4503 Reads the file <code>file</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4504 according to the given formats, which specify what to read.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4505 For each format,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4506 the function returns a string (or a number) with the characters read,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4507 or <b>nil</b> if it cannot read data with the specified format.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4508 When called without formats,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4509 it uses a default format that reads the next line
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4510 (see below).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4511
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4512
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4513 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4514 The available formats are
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4515
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4516 <ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4517
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4518 <li><b>"<code>*n</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4519 reads a number;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4520 this is the only format that returns a number instead of a string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4521 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4522
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4523 <li><b>"<code>*a</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4524 reads the whole file, starting at the current position.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4525 On end of file, it returns the empty string.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4526 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4527
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4528 <li><b>"<code>*l</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4529 reads the next line skipping the end of line,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4530 returning <b>nil</b> on end of file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4531 This is the default format.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4532 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4533
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4534 <li><b>"<code>*L</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4535 reads the next line keeping the end of line (if present),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4536 returning <b>nil</b> on end of file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4537 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4538
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4539 <li><b><em>number</em>: </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4540 reads a string with up to this number of bytes,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4541 returning <b>nil</b> on end of file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4542 If number is zero,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4543 it reads nothing and returns an empty string,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4544 or <b>nil</b> on end of file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4545 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4546
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4547 </ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4548
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4549
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4550
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4551 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4552 <hr><h3><a name="pdf-file:seek"><code>file:seek ([whence [, offset]])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4553
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4554
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4555 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4556 Sets and gets the file position,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4557 measured from the beginning of the file,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4558 to the position given by <code>offset</code> plus a base
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4559 specified by the string <code>whence</code>, as follows:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4560
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4561 <ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4562 <li><b>"<code>set</code>": </b> base is position 0 (beginning of the file);</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4563 <li><b>"<code>cur</code>": </b> base is current position;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4564 <li><b>"<code>end</code>": </b> base is end of file;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4565 </ul><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4566 In case of success, <code>seek</code> returns the final file position,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4567 measured in bytes from the beginning of the file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4568 If <code>seek</code> fails, it returns <b>nil</b>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4569 plus a string describing the error.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4570
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4571
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4572 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4573 The default value for <code>whence</code> is <code>"cur"</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4574 and for <code>offset</code> is 0.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4575 Therefore, the call <code>file:seek()</code> returns the current
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4576 file position, without changing it;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4577 the call <code>file:seek("set")</code> sets the position to the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4578 beginning of the file (and returns 0);
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4579 and the call <code>file:seek("end")</code> sets the position to the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4580 end of the file, and returns its size.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4581
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4582
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4583
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4584
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4585 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4586 <hr><h3><a name="pdf-file:setvbuf"><code>file:setvbuf (mode [, size])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4587
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4588
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4589 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4590 Sets the buffering mode for an output file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4591 There are three available modes:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4592
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4593 <ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4594
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4595 <li><b>"<code>no</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4596 no buffering; the result of any output operation appears immediately.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4597 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4598
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4599 <li><b>"<code>full</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4600 full buffering; output operation is performed only
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4601 when the buffer is full or when
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4602 you explicitly <code>flush</code> the file (see <a href="#pdf-io.flush"><code>io.flush</code></a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4603 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4604
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4605 <li><b>"<code>line</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4606 line buffering; output is buffered until a newline is output
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4607 or there is any input from some special files
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4608 (such as a terminal device).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4609 </li>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4610
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4611 </ul><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4612 For the last two cases, <code>size</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4613 specifies the size of the buffer, in bytes.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4614 The default is an appropriate size.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4615
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4616
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4617
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4618
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4619 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4620 <hr><h3><a name="pdf-file:write"><code>file:write (&middot;&middot;&middot;)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4621
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4622
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4623 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4624 Writes the value of each of its arguments to <code>file</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4625 The arguments must be strings or numbers.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4626
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4627
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4628 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4629 In case of success, this function returns <code>file</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4630 Otherwise it returns <b>nil</b> plus a string describing the error.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4631
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4632
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4633
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4634
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4635
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4636
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4637
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4638 <h2>6.9 &ndash; <a name="6.9">Operating System Facilities</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4639
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4640 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4641 This library is implemented through table <a name="pdf-os"><code>os</code></a>.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4642
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parents:
diff changeset
4643
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4644 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4645 <hr><h3><a name="pdf-os.clock"><code>os.clock ()</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4646
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4647
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4648 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4649 Returns an approximation of the amount in seconds of CPU time
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4650 used by the program.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4651
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4652
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4653
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4654
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4655 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4656 <hr><h3><a name="pdf-os.date"><code>os.date ([format [, time]])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4657
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4658
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4659 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4660 Returns a string or a table containing date and time,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4661 formatted according to the given string <code>format</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4662
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4663
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4664 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4665 If the <code>time</code> argument is present,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4666 this is the time to be formatted
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4667 (see the <a href="#pdf-os.time"><code>os.time</code></a> function for a description of this value).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4668 Otherwise, <code>date</code> formats the current time.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4669
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4670
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4671 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4672 If <code>format</code> starts with '<code>!</code>',
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4673 then the date is formatted in Coordinated Universal Time.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4674 After this optional character,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4675 if <code>format</code> is the string "<code>*t</code>",
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4676 then <code>date</code> returns a table with the following fields:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4677 <code>year</code> (four digits), <code>month</code> (1&ndash;12), <code>day</code> (1&ndash;31),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4678 <code>hour</code> (0&ndash;23), <code>min</code> (0&ndash;59), <code>sec</code> (0&ndash;61),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4679 <code>wday</code> (weekday, Sunday is&nbsp;1),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4680 <code>yday</code> (day of the year),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4681 and <code>isdst</code> (daylight saving flag, a boolean).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4682 This last field may be absent
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4683 if the information is not available.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4684
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4685
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4686 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4687 If <code>format</code> is not "<code>*t</code>",
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4688 then <code>date</code> returns the date as a string,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4689 formatted according to the same rules as the ANSI&nbsp;C function <code>strftime</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4690
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4691
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4692 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4693 When called without arguments,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4694 <code>date</code> returns a reasonable date and time representation that depends on
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4695 the host system and on the current locale
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4696 (that is, <code>os.date()</code> is equivalent to <code>os.date("%c")</code>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4697
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4698
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4699 <p>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4700 On non-Posix systems,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4701 this function may be not thread safe
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4702 because of its reliance on C&nbsp;function <code>gmtime</code> and C&nbsp;function <code>localtime</code>.
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4703
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
4704
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4705
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4706
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4707 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4708 <hr><h3><a name="pdf-os.difftime"><code>os.difftime (t2, t1)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4709
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4710
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4711 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4712 Returns the number of seconds from time <code>t1</code> to time <code>t2</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4713 In POSIX, Windows, and some other systems,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4714 this value is exactly <code>t2</code><em>-</em><code>t1</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4715
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4716
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4717
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4718
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4719 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4720 <hr><h3><a name="pdf-os.execute"><code>os.execute ([command])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4721
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4722
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4723 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4724 This function is equivalent to the ANSI&nbsp;C function <code>system</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4725 It passes <code>command</code> to be executed by an operating system shell.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4726 Its first result is <b>true</b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4727 if the command terminated successfully,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4728 or <b>nil</b> otherwise.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4729 After this first result
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4730 the function returns a string and a number,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4731 as follows:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4732
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4733 <ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4734
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4735 <li><b>"<code>exit</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4736 the command terminated normally;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4737 the following number is the exit status of the command.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4738 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4739
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4740 <li><b>"<code>signal</code>": </b>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4741 the command was terminated by a signal;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4742 the following number is the signal that terminated the command.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4743 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4744
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4745 </ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4746
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4747 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4748 When called without a <code>command</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4749 <code>os.execute</code> returns a boolean that is true if a shell is available.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4750
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4751
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4752
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4753
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4754 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4755 <hr><h3><a name="pdf-os.exit"><code>os.exit ([code [, close])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4756
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4757
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4758 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4759 Calls the ANSI&nbsp;C function <code>exit</code> to terminate the host program.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4760 If <code>code</code> is <b>true</b>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4761 the returned status is <code>EXIT_SUCCESS</code>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4762 if <code>code</code> is <b>false</b>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4763 the returned status is <code>EXIT_FAILURE</code>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4764 if <code>code</code> is a number,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4765 the returned status is this number.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4766 The default value for <code>code</code> is <b>true</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4767
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4768
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4769 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4770 If the optional second argument <code>close</code> is true,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4771 closes the Lua state before exiting.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4772
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4773
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4774
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4775
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4776 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4777 <hr><h3><a name="pdf-os.getenv"><code>os.getenv (varname)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4778
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4779
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4780 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4781 Returns the value of the process environment variable <code>varname</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4782 or <b>nil</b> if the variable is not defined.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4783
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4784
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4785
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4786
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4787 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4788 <hr><h3><a name="pdf-os.remove"><code>os.remove (filename)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4789
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4790
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4791 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4792 Deletes the file (or empty directory, on POSIX systems)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4793 with the given name.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4794 If this function fails, it returns <b>nil</b>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4795 plus a string describing the error and the error code.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4796
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4797
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4798
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4799
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4800 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4801 <hr><h3><a name="pdf-os.rename"><code>os.rename (oldname, newname)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4802
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4803
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4804 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4805 Renames file or directory named <code>oldname</code> to <code>newname</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4806 If this function fails, it returns <b>nil</b>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4807 plus a string describing the error and the error code.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4808
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4809
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4810
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4811
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4812 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4813 <hr><h3><a name="pdf-os.setlocale"><code>os.setlocale (locale [, category])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4814
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4815
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4816 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4817 Sets the current locale of the program.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4818 <code>locale</code> is a system-dependent string specifying a locale;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4819 <code>category</code> is an optional string describing which category to change:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4820 <code>"all"</code>, <code>"collate"</code>, <code>"ctype"</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4821 <code>"monetary"</code>, <code>"numeric"</code>, or <code>"time"</code>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4822 the default category is <code>"all"</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4823 The function returns the name of the new locale,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4824 or <b>nil</b> if the request cannot be honored.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4825
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4826
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4827 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4828 If <code>locale</code> is the empty string,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4829 the current locale is set to an implementation-defined native locale.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4830 If <code>locale</code> is the string "<code>C</code>",
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4831 the current locale is set to the standard C locale.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4832
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4833
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4834 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4835 When called with <b>nil</b> as the first argument,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4836 this function only returns the name of the current locale
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4837 for the given category.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4838
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4839
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4840 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4841 This function may be not thread safe
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4842 because of its reliance on C&nbsp;function <code>setlocale</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4843
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4844
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4845
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4846
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4847 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4848 <hr><h3><a name="pdf-os.time"><code>os.time ([table])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4849
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4850
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4851 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4852 Returns the current time when called without arguments,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4853 or a time representing the date and time specified by the given table.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4854 This table must have fields <code>year</code>, <code>month</code>, and <code>day</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4855 and may have fields
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4856 <code>hour</code> (default is 12),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4857 <code>min</code> (default is 0),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4858 <code>sec</code> (default is 0),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4859 and <code>isdst</code> (default is <b>nil</b>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4860 For a description of these fields, see the <a href="#pdf-os.date"><code>os.date</code></a> function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4861
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4862
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4863 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4864 The returned value is a number, whose meaning depends on your system.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4865 In POSIX, Windows, and some other systems,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4866 this number counts the number
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4867 of seconds since some given start time (the "epoch").
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4868 In other systems, the meaning is not specified,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4869 and the number returned by <code>time</code> can be used only as an argument to
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4870 <a href="#pdf-os.date"><code>os.date</code></a> and <a href="#pdf-os.difftime"><code>os.difftime</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4871
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4872
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4873
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4874
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4875 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4876 <hr><h3><a name="pdf-os.tmpname"><code>os.tmpname ()</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4877
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4878
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4879 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4880 Returns a string with a file name that can
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4881 be used for a temporary file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4882 The file must be explicitly opened before its use
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4883 and explicitly removed when no longer needed.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4884
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4885
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4886 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4887 On POSIX systems,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4888 this function also creates a file with that name,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4889 to avoid security risks.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4890 (Someone else might create the file with wrong permissions
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4891 in the time between getting the name and creating the file.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4892 You still have to open the file to use it
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4893 and to remove it (even if you do not use it).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4894
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4895
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4896 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4897 When possible,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4898 you may prefer to use <a href="#pdf-io.tmpfile"><code>io.tmpfile</code></a>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4899 which automatically removes the file when the program ends.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4900
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4901
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4902
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4903
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4904
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4905
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4906
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4907 <h2>6.10 &ndash; <a name="6.10">The Debug Library</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4908
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4909 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4910 This library provides
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4911 the functionality of the debug interface (<a href="#4.9">&sect;4.9</a>) to Lua programs.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4912 You should exert care when using this library.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4913 Several of its functions
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4914 violate basic assumptions about Lua code
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4915 (e.g., that variables local to a function
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4916 cannot be accessed from outside;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4917 that userdata metatables cannot be changed by Lua code;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4918 that Lua programs do not crash)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4919 and therefore can compromise otherwise secure code.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4920 Moreover, some functions in this library may be slow.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4921
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4922
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4923 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4924 All functions in this library are provided
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4925 inside the <a name="pdf-debug"><code>debug</code></a> table.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4926 All functions that operate over a thread
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4927 have an optional first argument which is the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4928 thread to operate over.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4929 The default is always the current thread.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4930
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4931
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4932 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4933 <hr><h3><a name="pdf-debug.debug"><code>debug.debug ()</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4934
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4935
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4936 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4937 Enters an interactive mode with the user,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4938 running each string that the user enters.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4939 Using simple commands and other debug facilities,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4940 the user can inspect global and local variables,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4941 change their values, evaluate expressions, and so on.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4942 A line containing only the word <code>cont</code> finishes this function,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4943 so that the caller continues its execution.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4944
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parents:
diff changeset
4945
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4946 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4947 Note that commands for <code>debug.debug</code> are not lexically nested
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4948 within any function and so have no direct access to local variables.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4949
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4950
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4951
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4952
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4953 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4954 <hr><h3><a name="pdf-debug.gethook"><code>debug.gethook ([thread])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4955
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4956
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4957 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4958 Returns the current hook settings of the thread, as three values:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4959 the current hook function, the current hook mask,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4960 and the current hook count
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4961 (as set by the <a href="#pdf-debug.sethook"><code>debug.sethook</code></a> function).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4962
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4963
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4964
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4965
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4966 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4967 <hr><h3><a name="pdf-debug.getinfo"><code>debug.getinfo ([thread,] f [, what])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4968
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4969
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4970 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4971 Returns a table with information about a function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4972 You can give the function directly
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4973 or you can give a number as the value of <code>f</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4974 which means the function running at level <code>f</code> of the call stack
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4975 of the given thread:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4976 level&nbsp;0 is the current function (<code>getinfo</code> itself);
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4977 level&nbsp;1 is the function that called <code>getinfo</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4978 (except for tail calls, which do not count on the stack);
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4979 and so on.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4980 If <code>f</code> is a number larger than the number of active functions,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4981 then <code>getinfo</code> returns <b>nil</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4982
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4983
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4984 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4985 The returned table can contain all the fields returned by <a href="#lua_getinfo"><code>lua_getinfo</code></a>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4986 with the string <code>what</code> describing which fields to fill in.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4987 The default for <code>what</code> is to get all information available,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4988 except the table of valid lines.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4989 If present,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4990 the option '<code>f</code>'
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4991 adds a field named <code>func</code> with the function itself.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4992 If present,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4993 the option '<code>L</code>'
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4994 adds a field named <code>activelines</code> with the table of
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4995 valid lines.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4996
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4997
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4998 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
4999 For instance, the expression <code>debug.getinfo(1,"n").name</code> returns
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5000 a table with a name for the current function,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5001 if a reasonable name can be found,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5002 and the expression <code>debug.getinfo(print)</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5003 returns a table with all available information
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5004 about the <a href="#pdf-print"><code>print</code></a> function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5005
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5006
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5007
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5008
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5009 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5010 <hr><h3><a name="pdf-debug.getlocal"><code>debug.getlocal ([thread,] f, local)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5011
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5012
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5013 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5014 This function returns the name and the value of the local variable
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5015 with index <code>local</code> of the function at level <code>f</code> of the stack.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5016 This function accesses not only explicit local variables,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5017 but also parameters, temporaries, etc.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5018
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5019
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5020 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5021 The first parameter or local variable has index&nbsp;1, and so on,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5022 until the last active variable.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5023 Negative indices refer to vararg parameters;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5024 -1 is the first vararg parameter.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5025 The function returns <b>nil</b> if there is no variable with the given index,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5026 and raises an error when called with a level out of range.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5027 (You can call <a href="#pdf-debug.getinfo"><code>debug.getinfo</code></a> to check whether the level is valid.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5028
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5029
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5030 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5031 Variable names starting with '<code>(</code>' (open parenthesis)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5032 represent internal variables
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5033 (loop control variables, temporaries, varargs, and C&nbsp;function locals).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5034
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5035
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5036 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5037 The parameter <code>f</code> may also be a function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5038 In that case, <code>getlocal</code> returns only the name of function parameters.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5039
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5040
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5041
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5042
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5043 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5044 <hr><h3><a name="pdf-debug.getmetatable"><code>debug.getmetatable (value)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5045
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5046
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5047 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5048 Returns the metatable of the given <code>value</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5049 or <b>nil</b> if it does not have a metatable.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5050
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5051
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5052
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5053
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5054 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5055 <hr><h3><a name="pdf-debug.getregistry"><code>debug.getregistry ()</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5056
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5057
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5058 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5059 Returns the registry table (see <a href="#4.5">&sect;4.5</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5060
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5061
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5062
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5063
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5064 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5065 <hr><h3><a name="pdf-debug.getupvalue"><code>debug.getupvalue (f, up)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5066
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5067
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5068 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5069 This function returns the name and the value of the upvalue
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5070 with index <code>up</code> of the function <code>f</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5071 The function returns <b>nil</b> if there is no upvalue with the given index.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5072
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5073
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5074
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5075
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5076 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5077 <hr><h3><a name="pdf-debug.getuservalue"><code>debug.getuservalue (u)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5078
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5079
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5080 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5081 Returns the Lua value associated to <code>u</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5082 If <code>u</code> is not a userdata,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5083 returns <b>nil</b>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5084
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5085
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5086
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5087
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5088 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5089 <hr><h3><a name="pdf-debug.sethook"><code>debug.sethook ([thread,] hook, mask [, count])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5090
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5091
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5092 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5093 Sets the given function as a hook.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5094 The string <code>mask</code> and the number <code>count</code> describe
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5095 when the hook will be called.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5096 The string mask may have the following characters,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5097 with the given meaning:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5098
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5099 <ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5100 <li><b>'<code>c</code>': </b> the hook is called every time Lua calls a function;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5101 <li><b>'<code>r</code>': </b> the hook is called every time Lua returns from a function;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5102 <li><b>'<code>l</code>': </b> the hook is called every time Lua enters a new line of code.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5103 </ul><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5104 With a <code>count</code> different from zero,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5105 the hook is called after every <code>count</code> instructions.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5106
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5107
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5108 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5109 When called without arguments,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5110 <a href="#pdf-debug.sethook"><code>debug.sethook</code></a> turns off the hook.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5111
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5112
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5113 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5114 When the hook is called, its first parameter is a string
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5115 describing the event that has triggered its call:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5116 <code>"call"</code> (or <code>"tail call"</code>),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5117 <code>"return"</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5118 <code>"line"</code>, and <code>"count"</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5119 For line events,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5120 the hook also gets the new line number as its second parameter.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5121 Inside a hook,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5122 you can call <code>getinfo</code> with level&nbsp;2 to get more information about
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5123 the running function
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5124 (level&nbsp;0 is the <code>getinfo</code> function,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5125 and level&nbsp;1 is the hook function).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5126
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5127
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5128
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5129
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5130 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5131 <hr><h3><a name="pdf-debug.setlocal"><code>debug.setlocal ([thread,] level, local, value)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5132
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5133
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5134 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5135 This function assigns the value <code>value</code> to the local variable
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5136 with index <code>local</code> of the function at level <code>level</code> of the stack.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5137 The function returns <b>nil</b> if there is no local
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5138 variable with the given index,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5139 and raises an error when called with a <code>level</code> out of range.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5140 (You can call <code>getinfo</code> to check whether the level is valid.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5141 Otherwise, it returns the name of the local variable.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5142
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5143
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5144 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5145 See <a href="#pdf-debug.getlocal"><code>debug.getlocal</code></a> for more information about
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5146 variable indices and names.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5147
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5148
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5149
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5150
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5151 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5152 <hr><h3><a name="pdf-debug.setmetatable"><code>debug.setmetatable (value, table)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5153
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5154
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5155 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5156 Sets the metatable for the given <code>value</code> to the given <code>table</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5157 (which can be <b>nil</b>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5158 Returns <code>value</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5159
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5160
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5161
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5162
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5163 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5164 <hr><h3><a name="pdf-debug.setupvalue"><code>debug.setupvalue (f, up, value)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5165
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5166
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5167 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5168 This function assigns the value <code>value</code> to the upvalue
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5169 with index <code>up</code> of the function <code>f</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5170 The function returns <b>nil</b> if there is no upvalue
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5171 with the given index.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5172 Otherwise, it returns the name of the upvalue.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5173
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5174
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5175
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5176
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5177 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5178 <hr><h3><a name="pdf-debug.setuservalue"><code>debug.setuservalue (udata, value)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5179
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5180
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5181 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5182 Sets the given <code>value</code> as
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5183 the Lua value associated to the given <code>udata</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5184 <code>value</code> must be a table or <b>nil</b>;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5185 <code>udata</code> must be a full userdata.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5186
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5187
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5188 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5189 Returns <code>udata</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5190
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5191
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5192
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5193
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5194 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5195 <hr><h3><a name="pdf-debug.traceback"><code>debug.traceback ([thread,] [message [, level]])</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5196
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5197
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5198 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5199 If <code>message</code> is present but is neither a string nor <b>nil</b>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5200 this function returns <code>message</code> without further processing.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5201 Otherwise,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5202 it returns a string with a traceback of the call stack.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5203 An optional <code>message</code> string is appended
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5204 at the beginning of the traceback.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5205 An optional <code>level</code> number tells at which level
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5206 to start the traceback
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5207 (default is 1, the function calling <code>traceback</code>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5208
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5209
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5210
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5211
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5212 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5213 <hr><h3><a name="pdf-debug.upvalueid"><code>debug.upvalueid (f, n)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5214
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5215
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5216 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5217 Returns an unique identifier (as a light userdata)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5218 for the upvalue numbered <code>n</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5219 from the given function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5220
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5221
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5222 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5223 These unique identifiers allow a program to check whether different
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5224 closures share upvalues.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5225 Lua closures that share an upvalue
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5226 (that is, that access a same external local variable)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5227 will return identical ids for those upvalue indices.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5228
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5229
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5230
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5231
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5232 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5233 <hr><h3><a name="pdf-debug.upvaluejoin"><code>debug.upvaluejoin (f1, n1, f2, n2)</code></a></h3>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5234
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5235
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5236 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5237 Make the <code>n1</code>-th upvalue of the Lua closure <code>f1</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5238 refer to the <code>n2</code>-th upvalue of the Lua closure <code>f2</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5239
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5240
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5241
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5242
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5243
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5244
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5245
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5246 <h1>7 &ndash; <a name="7">Lua Standalone</a></h1>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5247
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5248 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5249 Although Lua has been designed as an extension language,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5250 to be embedded in a host C&nbsp;program,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5251 it is also frequently used as a standalone language.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5252 An interpreter for Lua as a standalone language,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5253 called simply <code>lua</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5254 is provided with the standard distribution.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5255 The standalone interpreter includes
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5256 all standard libraries, including the debug library.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5257 Its usage is:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5258
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5259 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5260 lua [options] [script [args]]
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5261 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5262 The options are:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5263
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5264 <ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5265 <li><b><code>-e <em>stat</em></code>: </b> executes string <em>stat</em>;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5266 <li><b><code>-l <em>mod</em></code>: </b> "requires" <em>mod</em>;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5267 <li><b><code>-i</code>: </b> enters interactive mode after running <em>script</em>;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5268 <li><b><code>-v</code>: </b> prints version information;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5269 <li><b><code>-E</code>: </b> ignores environment variables;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5270 <li><b><code>--</code>: </b> stops handling options;</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5271 <li><b><code>-</code>: </b> executes <code>stdin</code> as a file and stops handling options.</li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5272 </ul><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5273 After handling its options, <code>lua</code> runs the given <em>script</em>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5274 passing to it the given <em>args</em> as string arguments.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5275 When called without arguments,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5276 <code>lua</code> behaves as <code>lua -v -i</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5277 when the standard input (<code>stdin</code>) is a terminal,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5278 and as <code>lua -</code> otherwise.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5279
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5280
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5281 <p>
242
b5a926c481a5 Handle first h1 tag differently.
hugo.tech@gmail.com <hugo.tech@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents: 241
diff changeset
5282 When called without option <code>-E</code>,
239
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5283 the interpreter checks for an environment variable <a name="pdf-LUA_INIT_5_2"><code>LUA_INIT_5_2</code></a>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5284 (or <a name="pdf-LUA_INIT"><code>LUA_INIT</code></a> if it is not defined)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5285 before running any argument.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5286 If the variable content has the format <code>@<em>filename</em></code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5287 then <code>lua</code> executes the file.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5288 Otherwise, <code>lua</code> executes the string itself.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5289
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5290
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5291 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5292 When called with option <code>-E</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5293 besides ignoring <code>LUA_INIT</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5294 Lua also ignores
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5295 the values of <code>LUA_PATH</code> and <code>LUA_CPATH</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5296 setting the values of
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5297 <a href="#pdf-package.path"><code>package.path</code></a> and <a href="#pdf-package.cpath"><code>package.cpath</code></a>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5298 with the default paths defined in <code>luaconf.h</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5299
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5300
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5301 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5302 All options are handled in order, except <code>-i</code> and <code>-E</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5303 For instance, an invocation like
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5304
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5305 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5306 $ lua -e'a=1' -e 'print(a)' script.lua
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5307 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5308 will first set <code>a</code> to 1, then print the value of <code>a</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5309 and finally run the file <code>script.lua</code> with no arguments.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5310 (Here <code>$</code> is the shell prompt. Your prompt may be different.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5311
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5312
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5313 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5314 Before starting to run the script,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5315 <code>lua</code> collects all arguments in the command line
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5316 in a global table called <code>arg</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5317 The script name is stored at index 0,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5318 the first argument after the script name goes to index 1,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5319 and so on.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5320 Any arguments before the script name
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5321 (that is, the interpreter name plus the options)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5322 go to negative indices.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5323 For instance, in the call
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5324
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5325 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5326 $ lua -la b.lua t1 t2
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5327 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5328 the interpreter first runs the file <code>a.lua</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5329 then creates a table
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5330
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5331 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5332 arg = { [-2] = "lua", [-1] = "-la",
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5333 [0] = "b.lua",
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5334 [1] = "t1", [2] = "t2" }
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5335 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5336 and finally runs the file <code>b.lua</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5337 The script is called with <code>arg[1]</code>, <code>arg[2]</code>, ...
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5338 as arguments;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5339 it can also access these arguments with the vararg expression '<code>...</code>'.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5340
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5341
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5342 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5343 In interactive mode,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5344 if you write an incomplete statement,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5345 the interpreter waits for its completion
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5346 by issuing a different prompt.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5347
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5348
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5349 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5350 In case of unprotected errors in the script,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5351 the interpreter reports the error to the standard error stream.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5352 If the error object is a string,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5353 the interpreter adds a stack traceback to it.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5354 Otherwise, if the error object has a metamethod <code>__tostring</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5355 the interpreter calls this metamethod to produce the final message.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5356 Finally, if the error object is <b>nil</b>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5357 the interpreter does not report the error.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5358
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5359
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5360 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5361 When finishing normally,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5362 the interpreter closes its main Lua state
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5363 (see <a href="#lua_close"><code>lua_close</code></a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5364 The script can avoid this step by
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5365 calling <a href="#pdf-os.exit"><code>os.exit</code></a> to terminate.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5366
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5367
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5368 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5369 To allow the use of Lua as a
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5370 script interpreter in Unix systems,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5371 the standalone interpreter skips
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5372 the first line of a chunk if it starts with <code>#</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5373 Therefore, Lua scripts can be made into executable programs
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5374 by using <code>chmod +x</code> and the&nbsp;<code>#!</code> form,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5375 as in
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5376
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5377 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5378 #!/usr/local/bin/lua
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5379 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5380 (Of course,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5381 the location of the Lua interpreter may be different in your machine.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5382 If <code>lua</code> is in your <code>PATH</code>,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5383 then
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5384
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5385 <pre>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5386 #!/usr/bin/env lua
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5387 </pre><p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5388 is a more portable solution.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5389
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5390
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5391
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5392 <h1>8 &ndash; <a name="8">Incompatibilities with the Previous Version</a></h1>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5393
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5394 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5395 Here we list the incompatibilities that you may find when moving a program
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5396 from Lua&nbsp;5.1 to Lua&nbsp;5.2.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5397 You can avoid some incompatibilities by compiling Lua with
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5398 appropriate options (see file <code>luaconf.h</code>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5399 However,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5400 all these compatibility options will be removed in the next version of Lua.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5401 Similarly,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5402 all features marked as deprecated in Lua&nbsp;5.1
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5403 have been removed in Lua&nbsp;5.2.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5404
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5405
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5406
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5407 <h2>8.1 &ndash; <a name="8.1">Changes in the Language</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5408 <ul>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5409
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5410 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5411 The concept of <em>environment</em> changed.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5412 Only Lua functions have environments.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5413 To set the environment of a Lua function,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5414 use the variable <code>_ENV</code> or the function <a href="#pdf-load"><code>load</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5415
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5416
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5417 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5418 C functions no longer have environments.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5419 Use an upvalue with a shared table if you need to keep
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5420 shared state among several C functions.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5421 (You may use <a href="#luaL_setfuncs"><code>luaL_setfuncs</code></a> to open a C library
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5422 with all functions sharing a common upvalue.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5423
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5424
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5425 <p>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5426 To manipulate the "environment" of a userdata
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5427 (which is now called user value),
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5428 use the new functions
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5429 <a href="#lua_getuservalue"><code>lua_getuservalue</code></a> and <a href="#lua_setuservalue"><code>lua_setuservalue</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5430 </li>
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parents:
diff changeset
5431
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5432 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5433 Lua identifiers cannot use locale-dependent letters.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5434 </li>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5435
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5436 <li>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5437 Doing a step or a full collection in the garbage collector
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5438 does not restart the collector if it has been stopped.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5439 </li>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5440
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5441 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5442 Weak tables with weak keys now perform like <em>ephemeron tables</em>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5443 </li>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5444
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5445 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5446 The event <em>tail return</em> in debug hooks was removed.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5447 Instead, tail calls generate a special new event,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5448 <em>tail call</em>, so that the debugger can know that
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5449 there will not be a corresponding return event.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5450 </li>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5451
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5452 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5453 Equality between function values has changed.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5454 Now, a function definition may not create a new value;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5455 it may reuse some previous value if there is no
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5456 observable difference to the new function.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5457 </li>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5458
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5459 </ul>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5460
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5461
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5462
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5463
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5464 <h2>8.2 &ndash; <a name="8.2">Changes in the Libraries</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5465 <ul>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5466
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5467 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5468 Function <code>module</code> is deprecated.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5469 It is easy to set up a module with regular Lua code.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5470 Modules are not expected to set global variables.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5471 </li>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5472
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5473 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5474 Functions <code>setfenv</code> and <code>getfenv</code> were removed,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5475 because of the changes in environments.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5476 </li>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5477
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5478 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5479 Function <code>math.log10</code> is deprecated.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5480 Use <a href="#pdf-math.log"><code>math.log</code></a> with 10 as its second argument, instead.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5481 </li>
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5482
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5483 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5484 Function <code>loadstring</code> is deprecated.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5485 Use <code>load</code> instead; it now accepts string arguments
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5486 and are exactly equivalent to <code>loadstring</code>.
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5487 </li>
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parents:
diff changeset
5488
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5489 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5490 Function <code>table.maxn</code> is deprecated.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5491 Write it in Lua if you really need it.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5492 </li>
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parents:
diff changeset
5493
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parents:
diff changeset
5494 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5495 Function <code>os.execute</code> now returns <b>true</b> when command
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5496 terminates successfully and <b>nil</b> plus error information
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5497 otherwise.
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5498 </li>
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parents:
diff changeset
5499
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parents:
diff changeset
5500 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5501 Function <code>unpack</code> was moved into the table library
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5502 and therefore must be called as <a href="#pdf-table.unpack"><code>table.unpack</code></a>.
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5503 </li>
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parents:
diff changeset
5504
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5505 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5506 Character class <code>%z</code> in patterns is deprecated,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5507 as now patterns may contain '<code>\0</code>' as a regular character.
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5508 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5509
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5510 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5511 The table <code>package.loaders</code> was renamed <code>package.searchers</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5512 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5513
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5514 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5515 Lua does not have bytecode verification anymore.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5516 So, all functions that load code
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5517 (<a href="#pdf-load"><code>load</code></a> and <a href="#pdf-loadfile"><code>loadfile</code></a>)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5518 are potentially insecure when loading untrusted binary data.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5519 (Actually, those functions were already insecure because
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5520 of flaws in the verification algorithm.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5521 When in doubt,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5522 use the <code>mode</code> argument of those functions
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5523 to restrict them to loading textual chunks.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5524 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5525
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5526 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5527 The standard paths in the official distribution may
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5528 change between versions.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5529 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5530
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5531 </ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5532
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5533
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5534
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5535
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5536 <h2>8.3 &ndash; <a name="8.3">Changes in the API</a></h2>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5537 <ul>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5538
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5539 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5540 Pseudoindex <code>LUA_GLOBALSINDEX</code> was removed.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5541 You must get the global environment from the registry
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5542 (see <a href="#4.5">&sect;4.5</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5543 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5544
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5545 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5546 Pseudoindex <code>LUA_ENVIRONINDEX</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5547 and functions <code>lua_getfenv</code>/<code>lua_setfenv</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5548 were removed,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5549 as C&nbsp;functions no longer have environments.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5550 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5551
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5552 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5553 Function <code>luaL_register</code> is deprecated.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5554 Use <a href="#luaL_setfuncs"><code>luaL_setfuncs</code></a> so that your module does not create globals.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5555 (Modules are not expected to set global variables anymore.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5556 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5557
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5558 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5559 The <code>osize</code> argument to the allocation function
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5560 may not be zero when creating a new block,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5561 that is, when <code>ptr</code> is <code>NULL</code>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5562 (see <a href="#lua_Alloc"><code>lua_Alloc</code></a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5563 Use only the test <code>ptr == NULL</code> to check whether
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5564 the block is new.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5565 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5566
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5567 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5568 Finalizers (<code>__gc</code> metamethods) for userdata are called in the
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5569 reverse order that they were marked for finalization,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5570 not that they were created (see <a href="#2.5.1">&sect;2.5.1</a>).
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5571 (Most userdata are marked immediately after they are created.)
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5572 Moreover,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5573 if the metatable does not have a <code>__gc</code> field when set,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5574 the finalizer will not be called,
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5575 even if it is set later.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5576 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5577
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5578 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5579 <code>luaL_typerror</code> was removed.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5580 Write your own version if you need it.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5581 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5582
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5583 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5584 Function <code>lua_cpcall</code> is deprecated.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5585 You can simply push the function with <a href="#lua_pushcfunction"><code>lua_pushcfunction</code></a>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5586 and call it with <a href="#lua_pcall"><code>lua_pcall</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5587 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5588
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5589 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5590 Functions <code>lua_equal</code> and <code>lua_lessthan</code> are deprecated.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5591 Use the new <a href="#lua_compare"><code>lua_compare</code></a> with appropriate options instead.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5592 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5593
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5594 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5595 Function <code>lua_objlen</code> was renamed <a href="#lua_rawlen"><code>lua_rawlen</code></a>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5596 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5597
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5598 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5599 Function <a href="#lua_load"><code>lua_load</code></a> has an extra parameter, <code>mode</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5600 Pass <code>NULL</code> to simulate the old behavior.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5601 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5602
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5603 <li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5604 Function <a href="#lua_resume"><code>lua_resume</code></a> has an extra parameter, <code>from</code>.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5605 Pass <code>NULL</code> or the thread doing the call.
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5606 </li>
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5607
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5608 </ul>
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parents:
diff changeset
5609
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diff changeset
5610
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diff changeset
5611
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diff changeset
5612
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parents:
diff changeset
5613 <h1>9 &ndash; <a name="9">The Complete Syntax of Lua</a></h1>
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diff changeset
5614
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parents:
diff changeset
5615 <p>
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parents:
diff changeset
5616 Here is the complete syntax of Lua in extended BNF.
aa7bc9c1df22 add unedited Lua manual
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diff changeset
5617 (It does not describe operator precedences.)
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diff changeset
5618
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diff changeset
5619
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diff changeset
5620
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diff changeset
5621
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5622 <pre>
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parents:
diff changeset
5623
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5624 chunk ::= block
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parents:
diff changeset
5625
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5626 block ::= {stat} [retstat]
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diff changeset
5627
242
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diff changeset
5628 stat ::= &lsquo;<b>;</b>&rsquo; |
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diff changeset
5629 varlist &lsquo;<b>=</b>&rsquo; explist |
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diff changeset
5630 functioncall |
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diff changeset
5631 label |
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diff changeset
5632 <b>break</b> |
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diff changeset
5633 <b>goto</b> Name |
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diff changeset
5634 <b>do</b> block <b>end</b> |
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diff changeset
5635 <b>while</b> exp <b>do</b> block <b>end</b> |
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diff changeset
5636 <b>repeat</b> block <b>until</b> exp |
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diff changeset
5637 <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] <b>end</b> |
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diff changeset
5638 <b>for</b> Name &lsquo;<b>=</b>&rsquo; exp &lsquo;<b>,</b>&rsquo; exp [&lsquo;<b>,</b>&rsquo; exp] <b>do</b> block <b>end</b> |
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diff changeset
5639 <b>for</b> namelist <b>in</b> explist <b>do</b> block <b>end</b> |
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parents: 241
diff changeset
5640 <b>function</b> funcname funcbody |
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diff changeset
5641 <b>local</b> <b>function</b> Name funcbody |
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diff changeset
5642 <b>local</b> namelist [&lsquo;<b>=</b>&rsquo; explist]
239
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diff changeset
5643
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5644 retstat ::= <b>return</b> [explist] [&lsquo;<b>;</b>&rsquo;]
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diff changeset
5645
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5646 label ::= &lsquo;<b>::</b>&rsquo; Name &lsquo;<b>::</b>&rsquo;
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parents:
diff changeset
5647
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5648 funcname ::= Name {&lsquo;<b>.</b>&rsquo; Name} [&lsquo;<b>:</b>&rsquo; Name]
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5649
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5650 varlist ::= var {&lsquo;<b>,</b>&rsquo; var}
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diff changeset
5651
242
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parents: 241
diff changeset
5652 var ::= Name | prefixexp &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo; | prefixexp &lsquo;<b>.</b>&rsquo; Name
239
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diff changeset
5653
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parents:
diff changeset
5654 namelist ::= Name {&lsquo;<b>,</b>&rsquo; Name}
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parents:
diff changeset
5655
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parents:
diff changeset
5656 explist ::= exp {&lsquo;<b>,</b>&rsquo; exp}
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diff changeset
5657
242
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diff changeset
5658 exp ::= <b>nil</b> | <b>false</b> | <b>true</b> | Number | String | &lsquo;<b>...</b>&rsquo; | functiondef |
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diff changeset
5659 prefixexp | tableconstructor | exp binop exp | unop exp
239
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diff changeset
5660
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parents:
diff changeset
5661 prefixexp ::= var | functioncall | &lsquo;<b>(</b>&rsquo; exp &lsquo;<b>)</b>&rsquo;
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diff changeset
5662
242
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diff changeset
5663 functioncall ::= prefixexp args | prefixexp &lsquo;<b>:</b>&rsquo; Name args
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diff changeset
5664
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diff changeset
5665 args ::= &lsquo;<b>(</b>&rsquo; [explist] &lsquo;<b>)</b>&rsquo; | tableconstructor | String
239
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diff changeset
5666
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5667 functiondef ::= <b>function</b> funcbody
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diff changeset
5668
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parents:
diff changeset
5669 funcbody ::= &lsquo;<b>(</b>&rsquo; [parlist] &lsquo;<b>)</b>&rsquo; block <b>end</b>
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diff changeset
5670
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parents:
diff changeset
5671 parlist ::= namelist [&lsquo;<b>,</b>&rsquo; &lsquo;<b>...</b>&rsquo;] | &lsquo;<b>...</b>&rsquo;
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
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diff changeset
5672
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diff changeset
5673 tableconstructor ::= &lsquo;<b>{</b>&rsquo; [fieldlist] &lsquo;<b>}</b>&rsquo;
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diff changeset
5674
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5675 fieldlist ::= field {fieldsep field} [fieldsep]
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diff changeset
5676
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parents:
diff changeset
5677 field ::= &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo; &lsquo;<b>=</b>&rsquo; exp | Name &lsquo;<b>=</b>&rsquo; exp | exp
aa7bc9c1df22 add unedited Lua manual
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diff changeset
5678
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diff changeset
5679 fieldsep ::= &lsquo;<b>,</b>&rsquo; | &lsquo;<b>;</b>&rsquo;
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diff changeset
5680
242
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diff changeset
5681 binop ::= &lsquo;<b>+</b>&rsquo; | &lsquo;<b>-</b>&rsquo; | &lsquo;<b>*</b>&rsquo; | &lsquo;<b>/</b>&rsquo; | &lsquo;<b>^</b>&rsquo; | &lsquo;<b>%</b>&rsquo; | &lsquo;<b>..</b>&rsquo; |
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diff changeset
5682 &lsquo;<b>&lt;</b>&rsquo; | &lsquo;<b>&lt;=</b>&rsquo; | &lsquo;<b>&gt;</b>&rsquo; | &lsquo;<b>&gt;=</b>&rsquo; | &lsquo;<b>==</b>&rsquo; | &lsquo;<b>~=</b>&rsquo; |
239
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diff changeset
5683 <b>and</b> | <b>or</b>
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diff changeset
5684
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parents:
diff changeset
5685 unop ::= &lsquo;<b>-</b>&rsquo; | <b>not</b> | &lsquo;<b>#</b>&rsquo;
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diff changeset
5686
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5687 </pre>
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parents:
diff changeset
5688
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parents:
diff changeset
5689 <p>
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parents:
diff changeset
5690
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parents:
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5691
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5692
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diff changeset
5693
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5694
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5695
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parents:
diff changeset
5696
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parents:
diff changeset
5697 <HR>
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parents:
diff changeset
5698 <SMALL CLASS="footer">
aa7bc9c1df22 add unedited Lua manual
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parents:
diff changeset
5699 Last update:
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5700 Thu Mar 21 13:01:53 BRT 2013
aa7bc9c1df22 add unedited Lua manual
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5701 </SMALL>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
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5702 <!--
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
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5703 Last change: revised for Lua 5.2.2
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
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5704 -->
aa7bc9c1df22 add unedited Lua manual
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parents:
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5705
aa7bc9c1df22 add unedited Lua manual
fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
parents:
diff changeset
5706 </body></html>
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fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
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5707