annotate website/src/manual.html.luan @ 1290:fb802d8aba0b

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author Franklin Schmidt <fschmidt@gmail.com>
date Wed, 02 Jan 2019 15:47:55 -0700
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1 local Luan = require "luan:Luan.luan"
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2 local Io = require "luan:Io.luan"
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3 local Html = require "luan:Html.luan"
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4 local Http = require "luan:http/Http.luan"
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5 local Shared = require "site:/Shared.luan"
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8 return function()
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9 Io.stdout = Http.response.text_writer()
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10 %>
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11 <!doctype html>
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12 <html>
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13 <head>
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14 <title>Luan Reference Manual</title>
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15 <style>
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16 @import "/site.css";
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17 </style>
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18 </head>
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19 <body>
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20
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21 <div container>
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22 <% Shared.header() %>
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23
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24 <h1>Luan Reference Manual</h1>
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25
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26 <p small>
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27 Original copyright &copy; 2015 Lua.org, PUC-Rio.
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28 Freely available under the terms of the
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29 <a href="http://www.lua.org/license.html">Lua license</a>.
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30 Modified for Luan.
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31 </p>
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32
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33 <hr/>
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34
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35 <h2>Contents</h2>
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36
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37 <div contents><a href="#intro">Introduction</a></div>
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38
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39 <div contents>
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40 <a href="#basic">Basic Concepts</a>
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41 <ul>
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42 <li><a href="#types">Values and Types</a></li>
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43 <li><a href="#env">Environments</a></li>
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44 <li><a href="#error">Error Handling</a></li>
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45 <li><a href="#meta">Metatables and Metamethods</a></li>
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46 <li><a href="#gc">Garbage Collection</a></li>
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47 </ul>
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48 </div>
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49
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50 <div contents>
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51 <a href="#lang">The Language</a>
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52 <ul>
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53 <li><a href="#lex">Lexical Conventions</a></li>
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54 <li><a href="#vars">Variables</a></li>
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55 <li>
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56 <a href="#stmts">Statements</a>
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57 <ul>
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58 <li><a href="#blocks">Blocks</a></li>
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59 <li><a href="#chunks">Chunks</a></li>
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60 <li><a href="#assignment">Assignment</a></li>
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61 <li><a href="#control">Control Structures</a></li>
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62 <li><a href="#for">For Statement</a></li>
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63 <li><a href="#fn_stmt">Function Calls as Statements</a></li>
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64 <li><a href="#local_stmt">Local Declarations</a></li>
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65 <li><a href="#template_stmt">Template Statements</a></li>
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66 </ul>
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67 </li>
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68 <li>
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69 <a href="#expressions">Expressions</a>
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70 <ul>
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71 <li><a href="#arithmetic">Arithmetic Operators</a></li>
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72 <li><a href="#conversions">Coercions and Conversions</a></li>
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73 <li><a href="#relational">Relational Operators</a></li>
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74 <li><a href="#logical_ops">Logical Operators</a></li>
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75 <li><a href="#concatenation">Concatenation</a></li>
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76 <li><a href="#length">The Length Operator</a></li>
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77 <li><a href="#precedence">Precedence</a></li>
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78 <li><a href="#constructors">Table Constructors</a></li>
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79 <li><a href="#fn_calls">Function Calls</a></li>
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80 <li><a href="#fn_def">Function Definitions</a></li>
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81 <li><a href="#template_expr">Template Expressions</a></li>
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82 </ul>
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83 </li>
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84 <li><a href="#visibility">Visibility Rules</a></li>
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85 </ul>
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86 </div>
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87
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88 <div contents>
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89 <a href="#libs">Standard Libraries</a>
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90 <ul>
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91 <li><a href="#default_lib">Default Environment</a></li>
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92 <li><a href="#luan_lib">Basic Functions</a></li>
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93 <li><a href="#package_lib">Modules</a></li>
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94 <li><a href="#string_lib">String Manipulation</a></li>
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95 <li><a href="#binary_lib">Binary Manipulation</a></li>
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96 <li><a href="#table_lib">Table Manipulation</a></li>
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97 <li><a href="#number_lib">Number Manipulation</a></li>
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98 <li><a href="#math_lib">Mathematical Functions</a></li>
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99 </ul>
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100 </div>
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101
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102 <hr/>
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103
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104
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105 <h2 heading><a name="intro">Introduction</a></h2>
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106
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107 <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 one can quickly learn the language and then easily understand any code written in Luan.</p>
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108
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109 <p>Luan is implemented in Java and is tightly coupled with Java. So it makes a great scripting language for Java programmers.</p>
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110
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111 <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.</p>
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113
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114 <h2 heading><a name="basic">Basic Concepts</a></h2>
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115
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116 <p>This section describes the basic concepts of the language.</p>
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117
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118 <h3 heading><a name="types">Values and Types</a></h3>
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119
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120 <p>
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121 Luan is a <em>dynamically typed language</em>.
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122 This means that
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123 variables do not have types; only values do.
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124 There are no type definitions in the language.
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125 All values carry their own type.
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128 <p>
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129 All values in Luan are <em>first-class values</em>.
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130 This means that all values can be stored in variables,
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131 passed as arguments to other functions, and returned as results.
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134 <p>
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135 There are eight basic types in Luan:
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136 <em>nil</em>, <em>boolean</em>, <em>number</em>,
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137 <em>string</em>, <em>binary</em>, <em>function</em>, <em>java</em>,
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138 and <em>table</em>.
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139 <em>Nil</em> is the type of the value <b>nil</b>,
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140 whose main property is to be different from any other value;
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141 it usually represents the absence of a useful value.
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142 <em>Nil</em> is implemented as the Java value <em>null</em>.
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143 <em>Boolean</em> is the type of the values <b>false</b> and <b>true</b>.
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144 <em>Boolean</em> is implemented as the Java class <em>Boolean</em>.
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145 <em>Number</em> represents both
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146 integer numbers and real (floating-point) numbers.
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147 <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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148 the underlying Java implementation.
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149
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150 <em>String</em> is implemented as the Java class <em>String</em>.
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151 <em>Binary</em> is implemented as the Java type <em>byte[]</em>.
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152
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153
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154 <p>
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155 Luan can call (and manipulate) functions written in Luan and
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156 functions written in Java (see <a href="#fn_calls">Function Calls</a>).
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157 Both are represented by the type <em>function</em>.
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158
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159
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160 <p>
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161 The type <em>java</em> is provided to allow arbitrary Java objects to
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162 be stored in Luan variables.
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163 A <em>java</em> value is a Java object that isn't one of the standard Luan types.
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164 Java values have no predefined operations in Luan,
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165 except assignment and identity test.
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166 Java values are useful when Java access is enabled in Luan
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167
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168
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169
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170 <p>
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171 The type <em>table</em> implements associative arrays,
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172 that is, arrays that can be indexed not only with numbers,
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173 but with any Luan value except <b>nil</b>.
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174 Tables can be <em>heterogeneous</em>;
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175 that is, they can contain values of all types (except <b>nil</b>).
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176 Any key with value <b>nil</b> is not considered part of the table.
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177 Conversely, any key that is not part of a table has
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178 an associated value <b>nil</b>.
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179
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180
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181 <p>
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182 Tables are the sole data-structuring mechanism in Luan;
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183 they can be used to represent ordinary arrays, sequences,
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184 symbol tables, sets, records, graphs, trees, etc.
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185 To represent records, Luan uses the field name as an index.
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186 The language supports this representation by
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187 providing <code>a.name</code> as syntactic sugar for <code>a["name"]</code>.
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188 There are several convenient ways to create tables in Luan
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189 (see <a href="#constructors">Table Constructors</a>).
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190
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191
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192 <p>
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193 We use the term <em>sequence</em> to denote a table where
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194 the set of all positive numeric keys is equal to {1..<em>n</em>}
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195 for some non-negative integer <em>n</em>,
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196 which is called the length of the sequence (see <a href="#length">The Length Operator</a>).
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197
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198
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199 <p>
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200 Like indices,
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201 the values of table fields can be of any type.
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202 In particular,
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203 because functions are first-class values,
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204 table fields can contain functions.
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205 Thus tables can also carry <em>methods</em> (see <a href="#fn_def">Function Definitions</a>).
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206
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207
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208 <p>
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209 The indexing of tables follows
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210 the definition of raw equality in the language.
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211 The expressions <code>a[i]</code> and <code>a[j]</code>
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212 denote the same table element
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213 if and only if <code>i</code> and <code>j</code> are raw equal
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214 (that is, equal without metamethods).
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215 In particular, floats with integral values
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216 are equal to their respective integers
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217 (e.g., <code>1.0 == 1</code>).
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218
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219
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220 <p>
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221 Luan values are <em>objects</em>:
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222 variables do not actually <em>contain</em> values,
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223 only <em>references</em> to them.
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224 Assignment, parameter passing, and function returns
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225 always manipulate references to values;
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226 these operations do not imply any kind of copy.
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227
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228
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229 <p>
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230 The library function <a href="#Luan.type"><code>Luan.type</code></a> returns a string describing the type
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231 of a given value.
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232
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233
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234
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235
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236
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237 <h3 heading><a name="env">Environments</a></h3>
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238
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239 <p>
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240 The environment of a chunk starts with only two local variables: <code><a href="#require">require</a></code> and <code><a href="#java">java</a></code>. These are functions are used to load and access libraries and other modules. All other variables must be added to the environment using <a href="http://localhost:8080/manual.html#local_stmt">local declarations</a>.
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241
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242 <p>
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243 As will be discussed in <a href="#vars">Variables</a> and <a href=#assignment">Assignment</a>,
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244 any reference to a free name
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245 (that is, a name not bound to any declaration) <code>var</code>
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246 can be syntactically translated to <code>_ENV.var</code> if <code>_ENV</code> is defined.
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247
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248
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249 <h3 heading><a name="error">Error Handling</a></h3>
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250
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251 <p>
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252 Luan code can explicitly generate an error by calling the
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253 <a href="#Luan.error"><code>error</code></a> function.
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254 If you need to catch errors in Luan,
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255 you can use <a href="#Luan.pcall"><code>pcall</code></a> or <a href="#Luan.try"><code>try</code></a>
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256 to call a given function in <em>protected mode</em>.
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257
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258
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259 <p>
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260 Whenever there is an error,
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261 an <em>error table</em>
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262 is propagated with information about the error.
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263 See <a href="#Luan.new_error"><code>Luan.new_error</code></a>.
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264
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265
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266
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267 <h3 heading><a name="meta">Metatables and Metamethods</a></h3>
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268
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269 <p>
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270 Every table in Luan can have a <em>metatable</em>.
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271 This <em>metatable</em> is an ordinary Luan table
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272 that defines the behavior of the original value
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273 under certain special operations.
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274 You can change several aspects of the behavior
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275 of operations over a value by setting specific fields in its metatable.
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276 For instance, when a table is the operand of an addition,
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277 Luan checks for a function in the field "<code>__add</code>" of the table's metatable.
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278 If it finds one,
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279 Luan calls this function to perform the addition.
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280
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281
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282 <p>
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283 The keys in a metatable are derived from the <em>event</em> names;
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284 the corresponding values are called <ii>metamethods</em>.
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285 In the previous example, the event is <code>"add"</code>
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286 and the metamethod is the function that performs the addition.
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287
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288
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289 <p>
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290 You can query the metatable of any table
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291 using the <a href="#Luan.get_metatable"><code>get_metatable</code></a> function.
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292
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293
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294 <p>
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295 You can replace the metatable of tables
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296 using the <a href="#Luan.set_metatable"><code>set_metatable</code></a> function.
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297
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298
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299 <p>
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300 A metatable controls how a table behaves in
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301 arithmetic operations, bitwise operations,
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302 order comparisons, concatenation, length operation, calls, and indexing.
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303
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304
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305 <p>
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306 A detailed list of events controlled by metatables is given next.
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307 Each operation is identified by its corresponding event name.
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308 The key for each event is a string with its name prefixed by
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309 two underscores, '<code>__</code>';
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310 for instance, the key for operation "add" is the
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311 string "<code>__add</code>".
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312 Note that queries for metamethods are always raw;
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313 the access to a metamethod does not invoke other metamethods.
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314 You can emulate how Luan queries a metamethod for an object <code>obj</code>
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315 with the following code:
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316
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317 <pre>
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318 raw_get(get_metatable(obj) or {}, "__" .. event_name)
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319 </pre>
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320
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321 <p>
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322 Here are the events:
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323
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324 <ul>
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325
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326 <li><p><b>"add": </b>
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327 the <code>+</code> operation.
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328
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329 If any operand for an addition is a table,
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330 Luan will try to call a metamethod.
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331 First, Luan will check the first operand (even if it is valid).
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332 If that operand does not define a metamethod for the "<code>__add</code>" event,
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333 then Luan will check the second operand.
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334 If Luan can find a metamethod,
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335 it calls the metamethod with the two operands as arguments,
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336 and the result of the call
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337 (adjusted to one value)
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338 is the result of the operation.
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339 Otherwise,
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340 it raises an error.
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341 </li>
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342
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343 <li><p><b>"sub": </b>
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344 the <code>-</code> operation.
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345
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346 Behavior similar to the "add" operation.
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347 </li>
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348
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349 <li><p><b>"mul": </b>
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350 the <code>*</code> operation.
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351
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352 Behavior similar to the "add" operation.
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353 </li>
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354
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355 <li><p><b>"div": </b>
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356 the <code>/</code> operation.
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357
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358 Behavior similar to the "add" operation.
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359 </li>
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360
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361 <li><p><b>"mod": </b>
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362 the <code>%</code> operation.
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363
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364 Behavior similar to the "add" operation.
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365 </li>
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366
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367 <li><p><b>"pow": </b>
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368 the <code>^</code> (exponentiation) operation.
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369
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370 Behavior similar to the "add" operation.
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371 </li>
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372
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373 <li><p><b>"unm": </b>
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374 the <code>-</code> (unary minus) operation.
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375
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376 Behavior similar to the "add" operation.
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377 </li>
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378
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379 <li><p><b>"concat": </b>
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380 the <code>..</code> (concatenation) operation.
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381
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382 Behavior similar to the "add" operation.
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383 </li>
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384
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385 <li><p><b>"len": </b>
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386 the <code>#</code> (length) operation.
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387
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388 If there is a metamethod,
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389 Luan calls it with the object as argument,
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390 and the result of the call
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391 (always adjusted to one value)
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392 is the result of the operation.
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393 If there is no metamethod but the object is a table,
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394 then Luan uses the table length operation (see <a href="#length">The Length Operator</a>).
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395 Otherwise, Luan raises an error.
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396 </li>
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397
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398 <li><p><b>"eq": </b>
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399 the <code>==</code> (equal) operation.
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400
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401 Behavior similar to the "add" operation,
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402 except that Luan will try a metamethod only when the values
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403 being compared are both tables
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404 and they are not primitively equal.
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405 The result of the call is always converted to a boolean.
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406 </li>
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407
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408 <li><p><b>"lt": </b>
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409 the <code>&lt;</code> (less than) operation.
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410
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411 Behavior similar to the "add" operation.
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412 The result of the call is always converted to a boolean.
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413 </li>
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414
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415 <li><p><b>"le": </b>
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416 the <code>&lt;=</code> (less equal) operation.
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417
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418 Unlike other operations,
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419 The less-equal operation can use two different events.
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420 First, Luan looks for the "<code>__le</code>" metamethod in both operands,
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421 like in the "lt" operation.
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422 If it cannot find such a metamethod,
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423 then it will try the "<code>__lt</code>" event,
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424 assuming that <code>a &lt;= b</code> is equivalent to <code>not (b &lt; a)</code>.
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425 As with the other comparison operators,
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426 the result is always a boolean.
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427 </li>
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428
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429 <li><p><b>"index": </b>
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430 The indexing access <code>table[key]</code>.
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431
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432 This event happens
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433 when <code>key</code> is not present in <code>table</code>.
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434 The metamethod is looked up in <code>table</code>.
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435
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436
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437 <p>
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438 Despite the name,
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439 the metamethod for this event can be any type.
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440 If it is a function,
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441 it is called with <code>table</code> and <code>key</code> as arguments.
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442 Otherwise
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443 the final result is the result of indexing this metamethod object with <code>key</code>.
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444 (This indexing is regular, not raw,
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445 and therefore can trigger another metamethod if the metamethod object is a table.)
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446 </li>
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447
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448 <li><p><b>"new_index": </b>
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449 The indexing assignment <code>table[key] = value</code>.
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450
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451 Like the index event,
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452 this event happens when
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453 when <code>key</code> is not present in <code>table</code>.
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454 The metamethod is looked up in <code>table</code>.
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455
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456
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457 <p>
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458 Like with indexing,
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459 the metamethod for this event can be either a function or a table.
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460 If it is a function,
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461 it is called with <code>table</code>, <code>key</code>, and <code>value</code> as arguments.
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462 If it is a table,
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463 Luan does an indexing assignment to this table with the same key and value.
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464 (This assignment is regular, not raw,
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465 and therefore can trigger another metamethod.)
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466
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467
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468 <p>
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469 Whenever there is a "new_index" metamethod,
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470 Luan does not perform the primitive assignment.
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471 (If necessary,
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472 the metamethod itself can call <a href="#Luan.raw_set"><code>raw_set</code></a>
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473 to do the assignment.)
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474 </li>
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475
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476 <li><p><b>"gc":</b>
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477 This is when a table is garbage collected. When the table's <a href="https://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#finalize()">finalize</a> method is called by the Java garbage collector, if there is a "<code>__gc</code>" metamethod then it is called with the table as a parameter.
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478
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479 </li>
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480
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481 </ul>
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482
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483
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484
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485
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486 <h3 heading><a name="gc">Garbage Collection</a></h3>
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487
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488 <p>
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489 Luan uses Java's garbage collection.
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490
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491
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492
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493
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494
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495 <h2 heading><a name="lang">The Language</a></h2>
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496
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497 <p>
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498 This section describes the lexis, the syntax, and the semantics of Luan.
371
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499 In other words,
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500 this section describes
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501 which tokens are valid,
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502 how they can be combined,
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503 and what their combinations mean.
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504
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505
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506 <p>
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507 Language constructs will be explained using the usual extended BNF notation,
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508 in which
562
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509 {<em>a</em>}&nbsp;means&nbsp;0 or more <em>a</em>'s, and
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510 [<em>a</em>]&nbsp;means an optional <em>a</em>.
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511 Non-terminals are shown like non-terminal,
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512 keywords are shown like <b>kword</b>,
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513 and other terminal symbols are shown like &lsquo;<b>=</b>&rsquo;.
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514 The complete syntax of Luan can be found in <a href="#9">&sect;9</a>
371
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515 at the end of this manual.
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516
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517
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518
562
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519 <h3 heading><a name="lex">Lexical Conventions</a></h3>
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520
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521 <p>
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522 Luan ignores spaces and comments
371
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523 between lexical elements (tokens),
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524 except as delimiters between names and keywords.
685
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525 Luan considers the end of a line to be the end of a statement. This catches errors and encourages readability. If you want to continue a statement on another line, you can use a backslash followed by a newline which will be treated as white space.
562
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526
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527 <p>
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528 <em>Names</em>
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529 (also called <em>identifiers</em>)
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530 in Luan can be any string of letters,
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531 digits, and underscores,
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532 not beginning with a digit.
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533 Identifiers are used to name variables, table fields, and labels.
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534
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535
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536 <p>
562
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537 The following <em>keywords</em> are reserved
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538 and cannot be used as names:
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539
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540
562
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541 <pre>
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542 and break do else elseif end
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543 end_do end_for end_function end_if end_while
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544 false for function goto if in
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545 local nil not or repeat return
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546 then true until while
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547 </pre>
371
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548
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549 <p>
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550 Luan is a case-sensitive language:
562
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551 <code>and</code> is a reserved word, but <code>And</code> and <code>AND</code>
371
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552 are two different, valid names.
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553
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554
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555 <p>
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556 The following strings denote other tokens:
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557
562
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558 <pre>
371
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559 + - * / % ^ #
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560 &amp; ~ | &lt;&lt; &gt;&gt; //
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561 == ~= &lt;= &gt;= &lt; &gt; =
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562 ( ) { } [ ] ::
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563 ; : , . .. ...
562
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diff changeset
564 </pre>
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565
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diff changeset
566 <p>
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567 <em>Literal strings</em>
371
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568 can be delimited by matching single or double quotes,
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569 and can contain the following C-like escape sequences:
562
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570 '<code>\a</code>' (bell),
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571 '<code>\b</code>' (backspace),
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572 '<code>\f</code>' (form feed),
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573 '<code>\n</code>' (newline),
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574 '<code>\r</code>' (carriage return),
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575 '<code>\t</code>' (horizontal tab),
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576 '<code>\v</code>' (vertical tab),
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577 '<code>\\</code>' (backslash),
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578 '<code>\"</code>' (quotation mark [double quote]),
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diff changeset
579 and '<code>\'</code>' (apostrophe [single quote]).
371
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580 A backslash followed by a real newline
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581 results in a newline in the string.
562
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582 The escape sequence '<code>\z</code>' skips the following span
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583 of white-space characters,
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584 including line breaks;
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585 it is particularly useful to break and indent a long literal string
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586 into multiple lines without adding the newlines and spaces
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587 into the string contents.
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588
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589
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590 <p>
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diff changeset
591 Luan can specify any character in a literal string by its numerical value.
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592 This can be done
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diff changeset
593 with the escape sequence <code>\x<em>XX</em></code>,
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diff changeset
594 where <em>XX</em> is a sequence of exactly two hexadecimal digits,
793
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diff changeset
595 or with the escape sequence <code>\u<em>XXXX</em></code>,
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596 where <em>XXXX</em> is a sequence of exactly four hexadecimal digits,
562
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diff changeset
597 or with the escape sequence <code>\<em>ddd</em></code>,
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598 where <em>ddd</em> is a sequence of up to three decimal digits.
371
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599 (Note that if a decimal escape sequence is to be followed by a digit,
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600 it must be expressed using exactly three digits.)
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601
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602
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603 <p>
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604 Literal strings can also be defined using a long format
562
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diff changeset
605 enclosed by <em>long brackets</em>.
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606 We define an <em>opening long bracket of level <em>n</em></em> as an opening
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607 square bracket followed by <em>n</em> equal signs followed by another
371
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608 opening square bracket.
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diff changeset
609 So, an opening long bracket of level 0 is written as <code>[[</code>,
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610 an opening long bracket of level 1 is written as <code>[=[</code>,
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611 and so on.
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612 A <em>closing long bracket</em> is defined similarly;
371
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613 for instance,
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614 a closing long bracket of level 4 is written as <code>]====]</code>.
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615 A <em>long literal</em> starts with an opening long bracket of any level and
371
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616 ends at the first closing long bracket of the same level.
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617 It can contain any text except a closing bracket of the same level.
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618 Literals in this bracketed form can run for several lines,
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619 do not interpret any escape sequences,
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620 and ignore long brackets of any other level.
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621 Any kind of end-of-line sequence
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622 (carriage return, newline, carriage return followed by newline,
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623 or newline followed by carriage return)
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624 is converted to a simple newline.
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625
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626
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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627 <p>
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628 Any character in a literal string not
371
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629 explicitly affected by the previous rules represents itself.
380
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630 However, Luan opens files for parsing in text mode,
371
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631 and the system file functions may have problems with
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632 some control characters.
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633 So, it is safer to represent
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634 non-text data as a quoted literal with
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635 explicit escape sequences for non-text characters.
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parents:
diff changeset
636
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parents:
diff changeset
637
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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638 <p>
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639 For convenience,
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640 when the opening long bracket is immediately followed by a newline,
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641 the newline is not included in the string.
380
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diff changeset
642 As an example
371
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643 the five literal strings below denote the same string:
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644
562
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diff changeset
645 <pre>
371
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646 a = 'alo\n123"'
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647 a = "alo\n123\""
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648 a = '\97lo\10\04923"'
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649 a = [[alo
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diff changeset
650 123"]]
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651 a = [==[
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652 alo
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653 123"]==]
562
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diff changeset
654 </pre>
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diff changeset
655
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diff changeset
656 <p>
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diff changeset
657 A <em>numerical constant</em> (or <em>numeral</em>)
371
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658 can be written with an optional fractional part
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659 and an optional decimal exponent,
562
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660 marked by a letter '<code>e</code>' or '<code>E</code>'.
380
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diff changeset
661 Luan also accepts hexadecimal constants,
562
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662 which start with <code>0x</code> or <code>0X</code>.
371
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663 Hexadecimal constants also accept an optional fractional part
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664 plus an optional binary exponent,
562
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665 marked by a letter '<code>p</code>' or '<code>P</code>'.
371
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666 A numeric constant with a fractional dot or an exponent
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parents:
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667 denotes a float;
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668 otherwise it denotes an integer.
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parents:
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669 Examples of valid integer constants are
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parents:
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670
562
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diff changeset
671 <pre>
371
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672 3 345 0xff 0xBEBADA
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diff changeset
673 </pre>
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674
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diff changeset
675 <p>
371
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676 Examples of valid float constants are
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677
562
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diff changeset
678 <pre>
371
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679 3.0 3.1416 314.16e-2 0.31416E1 34e1
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680 0x0.1E 0xA23p-4 0X1.921FB54442D18P+1
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diff changeset
681 </pre>
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parents: 556
diff changeset
682
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diff changeset
683 <p>
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parents: 556
diff changeset
684 A <em>comment</em> starts with a double hyphen (<code>--</code>)
371
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685 anywhere outside a string.
562
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diff changeset
686 If the text immediately after <code>--</code> is not an opening long bracket,
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diff changeset
687 the comment is a <em>short comment</em>,
371
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688 which runs until the end of the line.
562
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diff changeset
689 Otherwise, it is a <em>long comment</em>,
371
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diff changeset
690 which runs until the corresponding closing long bracket.
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parents:
diff changeset
691 Long comments are frequently used to disable code temporarily.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
692
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
693
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
694
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
695
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
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696
562
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diff changeset
697 <h3 heading><a name="vars">Variables</a></h3>
371
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diff changeset
698
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parents:
diff changeset
699 <p>
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diff changeset
700 Variables are places that store values.
380
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701 There are three kinds of variables in Luan:
371
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parents:
diff changeset
702 global variables, local variables, and table fields.
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parents:
diff changeset
703
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
704 <p>
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parents:
diff changeset
705 A single name can denote a global variable or a local variable
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parents:
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706 (or a function's formal parameter,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
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707 which is a particular kind of local variable):
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parents:
diff changeset
708
562
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diff changeset
709 <pre>
371
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diff changeset
710 var ::= Name
562
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diff changeset
711 </pre>
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diff changeset
712
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diff changeset
713 <p>
464
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diff changeset
714 Name denotes identifiers, as defined in <a href="#lex">Lexical Conventions</a>.
371
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parents:
diff changeset
715
512
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parents: 505
diff changeset
716 <p>
562
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diff changeset
717 Local variables are <em>lexically scoped</em>:
371
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718 local variables can be freely accessed by functions
464
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parents: 429
diff changeset
719 defined inside their scope (see <a href="#visibility">Visibility Rules</a>).
371
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parents:
diff changeset
720
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parents:
diff changeset
721
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
722 <p>
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parents:
diff changeset
723 Before the first assignment to a variable, its value is <b>nil</b>.
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parents:
diff changeset
724
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
725 <p>
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parents:
diff changeset
726 Square brackets are used to index a table:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
727
562
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diff changeset
728 <pre>
371
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729 var ::= prefixexp &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo;
562
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diff changeset
730 </pre>
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diff changeset
731
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diff changeset
732 <p>
371
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733 The meaning of accesses to table fields can be changed via metatables.
562
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diff changeset
734 An access to an indexed variable <code>t[i]</code> is equivalent to
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diff changeset
735 a call <code>gettable_event(t,i)</code>.
464
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diff changeset
736 (See <a href="#meta">Metatables and Metamethods</a> for a complete description of the
562
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diff changeset
737 <code>gettable_event</code> function.
380
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738 This function is not defined or callable in Luan.
371
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739 We use it here only for explanatory purposes.)
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740
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741
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742 <p>
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diff changeset
743 The syntax <code>var.Name</code> is just syntactic sugar for
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diff changeset
744 <code>var["Name"]</code>:
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745
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diff changeset
746 <pre>
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747 var ::= prefixexp &lsquo;<b>.</b>&rsquo; Name
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diff changeset
748 </pre>
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diff changeset
749
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750 <p>
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751 Global variables are not available by default. To enable global variable, you must define <code>_ENV</code> as a local variable whose value is a table. If <code>_ENV</code> is not defined, then an unrecognized variable name will produce a compile error. If <code>_ENV</code> is defined then an access to an unrecognized variable name will be consider a global variable. So then an acces to global variable <code>x</code>
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752 is equivalent to <code>_ENV.x</code>.
371
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753 Due to the way that chunks are compiled,
562
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754 <code>_ENV</code> is never a global name (see <a href="#env">Environments</a>).
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755
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diff changeset
756
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diff changeset
757
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diff changeset
758
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diff changeset
759
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diff changeset
760 <h3 heading><a name="stmts">Statements</a></h3>
389
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diff changeset
761
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diff changeset
762 <p>
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diff changeset
763 Luan supports an almost conventional set of statements,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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764 similar to those in Pascal or C.
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765 This set includes
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766 assignments, control structures, function calls,
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767 and variable declarations.
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768
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
769
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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770
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771 <h4 heading><a name="blocks">Blocks</a></h4>
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772
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773 <p>
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774 A block is a list of statements,
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775 which are executed sequentially:
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776
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diff changeset
777 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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778 block ::= {stat}
562
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diff changeset
779 </pre>
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diff changeset
780
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diff changeset
781 <p>
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diff changeset
782 Luan has <em>empty statements</em>
371
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783 that allow you to separate statements with semicolons,
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diff changeset
784 start a block with a semicolon
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785 or write two semicolons in sequence:
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786
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diff changeset
787 <pre>
371
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788 stat ::= &lsquo;<b>;</b>&rsquo;
562
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diff changeset
789 </pre>
371
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790
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diff changeset
791 <p>
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792 A block can be explicitly delimited to produce a single statement:
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793
562
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diff changeset
794 <pre>
1092
a26fbde7ee28 documentation
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diff changeset
795 stat ::= <b>do</b> block end_do
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parents: 1090
diff changeset
796 end_do ::= <b>end_do</b> | <b>end</b>
562
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diff changeset
797 </pre>
389
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diff changeset
798
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diff changeset
799 <p>
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diff changeset
800 Explicit blocks are useful
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801 to control the scope of variable declarations.
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diff changeset
802 Explicit blocks are also sometimes used to
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diff changeset
803 add a <b>return</b> statement in the middle
464
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804 of another block (see <a href="#control">Control Structures</a>).
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
805
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
806
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
807
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
808
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
809
562
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diff changeset
810 <h4 heading><a name="chunks">Chunks</a></h4>
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diff changeset
811
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diff changeset
812 <p>
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diff changeset
813 The unit of compilation of Luan is called a <em>chunk</em>.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
814 Syntactically,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
815 a chunk is simply a block:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
816
562
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diff changeset
817 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
818 chunk ::= block
562
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diff changeset
819 </pre>
395
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diff changeset
820
a7cb58532846 work on manual
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diff changeset
821 <p>
a7cb58532846 work on manual
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diff changeset
822 Luan handles a chunk as the body of an anonymous function
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
823 with a variable number of arguments
464
eddf7c73373b fix references in the manual
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diff changeset
824 (see <a href="#fn_def">Function Definitions</a>).
371
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825 As such, chunks can define local variables,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
826 receive arguments, and return values.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
827
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parents:
diff changeset
828
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
829 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
830 A chunk can be stored in a file or in a string inside the host program.
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diff changeset
831 To execute a chunk,
562
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diff changeset
832 Luan first <em>loads</em> it,
395
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diff changeset
833 compiling the chunk's code,
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diff changeset
834 and then Luan executes the compiled code.
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diff changeset
835
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diff changeset
836
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diff changeset
837
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diff changeset
838
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diff changeset
839
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diff changeset
840 <h4 heading><a name="assignment">Assignment</a></h4>
395
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diff changeset
841
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diff changeset
842 <p>
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diff changeset
843 Luan allows multiple assignments.
371
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diff changeset
844 Therefore, the syntax for assignment
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parents:
diff changeset
845 defines a list of variables on the left side
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
846 and a list of expressions on the right side.
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parents:
diff changeset
847 The elements in both lists are separated by commas:
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parents:
diff changeset
848
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diff changeset
849 <pre>
371
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diff changeset
850 stat ::= varlist &lsquo;<b>=</b>&rsquo; explist
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parents:
diff changeset
851 varlist ::= var {&lsquo;<b>,</b>&rsquo; var}
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parents:
diff changeset
852 explist ::= exp {&lsquo;<b>,</b>&rsquo; exp}
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diff changeset
853 </pre>
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diff changeset
854
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diff changeset
855 <p>
464
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diff changeset
856 Expressions are discussed in <a href="#expressions">Expressions</a>.
371
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parents:
diff changeset
857
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
858
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
859 <p>
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parents:
diff changeset
860 Before the assignment,
562
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diff changeset
861 the list of values is <em>adjusted</em> to the length of
371
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diff changeset
862 the list of variables.
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parents:
diff changeset
863 If there are more values than needed,
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864 the excess values are thrown away.
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diff changeset
865 If there are fewer values than needed,
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diff changeset
866 the list is extended with as many <b>nil</b>'s as needed.
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diff changeset
867 If the list of expressions ends with a function call,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
868 then all values returned by that call enter the list of values,
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diff changeset
869 before the adjustment
464
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diff changeset
870 (except when the call is enclosed in parentheses; see <a href="#expressions">Expressions</a>).
371
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diff changeset
871
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parents:
diff changeset
872
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
873 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
874 The assignment statement first evaluates all its expressions
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diff changeset
875 and only then the assignments are performed.
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diff changeset
876 Thus the code
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diff changeset
877
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diff changeset
878 <pre>
371
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diff changeset
879 i = 3
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diff changeset
880 i, a[i] = i+1, 20
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diff changeset
881 </pre>
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diff changeset
882
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diff changeset
883 <p>
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diff changeset
884 sets <code>a[3]</code> to 20, without affecting <code>a[4]</code>
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885 because the <code>i</code> in <code>a[i]</code> is evaluated (to 3)
371
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diff changeset
886 before it is assigned&nbsp;4.
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parents:
diff changeset
887 Similarly, the line
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diff changeset
888
562
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diff changeset
889 <pre>
371
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diff changeset
890 x, y = y, x
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diff changeset
891 </pre>
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diff changeset
892
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diff changeset
893 <p>
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diff changeset
894 exchanges the values of <code>x</code> and <code>y</code>,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
895 and
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
896
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diff changeset
897 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
898 x, y, z = y, z, x
562
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diff changeset
899 </pre>
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diff changeset
900
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diff changeset
901 <p>
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diff changeset
902 cyclically permutes the values of <code>x</code>, <code>y</code>, and <code>z</code>.
371
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diff changeset
903
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parents:
diff changeset
904
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diff changeset
905 <p>
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diff changeset
906 The meaning of assignments to global variables
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907 and table fields can be changed via metatables.
562
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diff changeset
908 An assignment to an indexed variable <code>t[i] = val</code> is equivalent to
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diff changeset
909 <code>settable_event(t,i,val)</code>.
464
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910 (See <a href="#meta">Metatables and Metamethods</a> for a complete description of the
562
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diff changeset
911 <code>settable_event</code> function.
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912 This function is not defined or callable in Luan.
371
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913 We use it here only for explanatory purposes.)
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914
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915
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916 <p>
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diff changeset
917 An assignment to a global name <code>x = val</code>
371
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918 is equivalent to the assignment
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diff changeset
919 <code>_ENV.x = val</code> (see <a href="#env">Environments</a>).
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920 Global names are only available when <code>_ENV</code> is defined.
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diff changeset
921
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922
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923
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924 <h4 heading><a name="control">Control Structures</a></h4>
395
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925
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926 <p>
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927 The control structures
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928 <b>if</b>, <b>while</b>, and <b>repeat</b> have the usual meaning and
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diff changeset
929 familiar syntax:
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930
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diff changeset
931 <pre>
1092
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932 stat ::= <b>while</b> exp <b>do</b> block end_while
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933 stat ::= <b>repeat</b> block <b>until</b> exp
1092
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diff changeset
934 stat ::= <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] end_if
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diff changeset
935 end_while ::= <b>end_while</b> | <b>end</b>
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diff changeset
936 end_if ::= <b>end_if</b> | <b>end</b>
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diff changeset
937 </pre>
395
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diff changeset
938
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diff changeset
939 <p>
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eddf7c73373b fix references in the manual
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diff changeset
940 Luan also has a <b>for</b> statement (see <a href="#for">For Statement</a>).
371
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941
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942
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diff changeset
943 <p>
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944 The condition expression of a
395
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diff changeset
945 control structure must be a boolean.
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946 Any other value type will produce an error.
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diff changeset
947 This helps catch errors and makes code more readable.
371
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diff changeset
948
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diff changeset
949
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diff changeset
950 <p>
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diff changeset
951 In the <b>repeat</b>&ndash;<b>until</b> loop,
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952 the inner block does not end at the <b>until</b> keyword,
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953 but only after the condition.
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954 So, the condition can refer to local variables
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955 declared inside the loop block.
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956
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diff changeset
957
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diff changeset
958 <p>
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959 The <b>break</b> statement terminates the execution of a
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960 <b>while</b>, <b>repeat</b>, or <b>for</b> loop,
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diff changeset
961 skipping to the next statement after the loop:
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diff changeset
962
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963
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diff changeset
964 <pre>
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diff changeset
965 stat ::= <b>break</b>
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diff changeset
966 </pre>
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diff changeset
967
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diff changeset
968 <p>
371
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969 A <b>break</b> ends the innermost enclosing loop.
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diff changeset
970
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parents:
diff changeset
971
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diff changeset
972 <p>
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diff changeset
973 The <b>return</b> statement is used to return values
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diff changeset
974 from a function or a chunk
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975 (which is an anonymous function).
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diff changeset
976
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diff changeset
977 Functions can return more than one value,
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978 so the syntax for the <b>return</b> statement is
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diff changeset
979
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diff changeset
980 <pre>
371
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diff changeset
981 stat ::= <b>return</b> [explist] [&lsquo;<b>;</b>&rsquo;]
562
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diff changeset
982 </pre>
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parents: 556
diff changeset
983
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diff changeset
984
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parents: 556
diff changeset
985
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diff changeset
986
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diff changeset
987 <h4 heading><a name="for">For Statement</a></h4>
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diff changeset
988
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diff changeset
989 <p>
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diff changeset
990 The <b>for</b> statement works over functions,
562
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diff changeset
991 called <em>iterators</em>.
395
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diff changeset
992 On each iteration, the iterator function is called to produce a new value,
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diff changeset
993 stopping when this new value is <b>nil</b>.
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diff changeset
994 The <b>for</b> loop has the following syntax:
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diff changeset
995
562
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diff changeset
996 <pre>
1092
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parents: 1090
diff changeset
997 stat ::= <b>for</b> namelist <b>in</b> exp <b>do</b> block end_for
395
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diff changeset
998 namelist ::= Name {&lsquo;<b>,</b>&rsquo; Name}
1092
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diff changeset
999 end_for ::= <b>end_for</b> | <b>end</b>
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diff changeset
1000 </pre>
395
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diff changeset
1001
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diff changeset
1002 <p>
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diff changeset
1003 A <b>for</b> statement like
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diff changeset
1004
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1005 <pre>
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diff changeset
1006 for <em>var_1</em>, &middot;&middot;&middot;, <em>var_n</em> in <em>exp</em> do <em>block</em> end
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1007 </pre>
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diff changeset
1008
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diff changeset
1009 <p>
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1010 is equivalent to the code:
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1011
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1012 <pre>
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1013 do
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diff changeset
1014 local <em>f</em> = <em>exp</em>
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1015 while true do
562
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diff changeset
1016 local <em>var_1</em>, &middot;&middot;&middot;, <em>var_n</em> = <em>f</em>()
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1017 if <em>var_1</em> == nil then break end
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diff changeset
1018 <em>block</em>
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1019 end
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1020 end
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diff changeset
1021 </pre>
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diff changeset
1022
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diff changeset
1023 <p>
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parents:
diff changeset
1024 Note the following:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1025
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parents:
diff changeset
1026 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1027
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1028 <li>
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diff changeset
1029 <code><em>exp</em></code> is evaluated only once.
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diff changeset
1030 Its result is an <em>iterator</em> function.
371
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diff changeset
1031 </li>
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parents:
diff changeset
1032
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diff changeset
1033 <li>
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diff changeset
1034 <code><em>f</em></code> is an invisible variable.
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diff changeset
1035 The name is here for explanatory purposes only.
371
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1036 </li>
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parents:
diff changeset
1037
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1038 <li>
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1039 You can use <b>break</b> to exit a <b>for</b> loop.
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1040 </li>
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diff changeset
1041
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diff changeset
1042 <li>
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1043 The loop variables <code><em>var_i</em></code> are local to the loop;
371
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1044 you cannot use their values after the <b>for</b> ends.
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1045 If you need these values,
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diff changeset
1046 then assign them to other variables before breaking or exiting the loop.
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1047 </li>
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1048
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diff changeset
1049 </ul>
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diff changeset
1050
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1051
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diff changeset
1052
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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1053
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1054 <h4 heading><a name="fn_stmt">Function Calls as Statements</a></h4>
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diff changeset
1055
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1056 <p>
371
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1057 To allow possible side-effects,
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1058 function calls can be executed as statements:
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1059
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1060 <pre>
371
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1061 stat ::= functioncall
562
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1062 </pre>
395
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diff changeset
1063
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1064 <p>
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1065 In this case, all returned values are thrown away.
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1066 Function calls are explained in <a href="#fn_calls">Function Calls</a>.
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1067
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1068
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1069
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diff changeset
1070 <h4 heading><a name="local_stmt">Local Declarations</a></h4>
395
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diff changeset
1071
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1072 <p>
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1073 Local variables can be declared anywhere inside a block.
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1074 The declaration can include an initial assignment:
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1075
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1076 <pre>
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1077 stat ::= <b>local</b> namelist [&lsquo;<b>=</b>&rsquo; explist]
562
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diff changeset
1078 </pre>
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diff changeset
1079
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1080 <p>
371
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1081 If present, an initial assignment has the same semantics
464
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1082 of a multiple assignment (see <a href="#assignment">Assignment</a>).
371
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1083 Otherwise, all variables are initialized with <b>nil</b>.
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diff changeset
1084
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diff changeset
1085
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1086 <p>
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1087 A chunk is also a block (see <a href="#chunks">Chunks</a>),
371
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1088 and so local variables can be declared in a chunk outside any explicit block.
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diff changeset
1089
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diff changeset
1090
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1091 <p>
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diff changeset
1092 The visibility rules for local variables are explained in <a href="#visibility">Visibility Rules</a>.
371
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1093
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diff changeset
1094
562
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diff changeset
1095 <h4 heading><a name="template_stmt">Template Statements</a></h4>
465
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diff changeset
1096
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diff changeset
1097 <p>Template statements are based on <a href="#template_expr">template exressions</a> and provide the full equivalent of <a href="http://en.wikipedia.org/wiki/JavaServer_Pages">JSP</a> but in a general way. Template statements write the equivalent template exression to standard output. For example:</p>
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1098
562
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diff changeset
1099 <pre><%=Html.encode[[
465
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diff changeset
1100 local name = "Bob"
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1101 %>
469
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1102 Hello <%= name %>!
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1103 Bye <%= name %>.
465
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1104 <%
562
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diff changeset
1105 ]]%></pre>
465
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diff changeset
1106
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1107 <p>is equivalent to the code:</p>
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1108
562
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diff changeset
1109 <pre><%=Html.encode[[
465
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diff changeset
1110 local name = "Bob"
693
ca169567ce07 module URIs must now include ".luan"
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parents: 685
diff changeset
1111 require("luan:Io.luan").stdout.write( %>
469
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diff changeset
1112 Hello <%= name %>!
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1113 Bye <%= name %>.
465
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diff changeset
1114 <% )
562
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diff changeset
1115 ]]%></pre>
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diff changeset
1116
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1117
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diff changeset
1118
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1119 <h3 heading><a name="expressions">Expressions</a></h3>
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diff changeset
1120
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1121 <p>
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1122 The basic expressions in Luan are the following:
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1123
562
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1124 <pre>
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1125 exp ::= prefixexp
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diff changeset
1126 exp ::= <b>nil</b> | <b>false</b> | <b>true</b>
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1127 exp ::= Numeral
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diff changeset
1128 exp ::= LiteralString
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diff changeset
1129 exp ::= functiondef
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diff changeset
1130 exp ::= tableconstructor
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parents:
diff changeset
1131 exp ::= &lsquo;<b>...</b>&rsquo;
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diff changeset
1132 exp ::= exp binop exp
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parents:
diff changeset
1133 exp ::= unop exp
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parents:
diff changeset
1134 prefixexp ::= var | functioncall | &lsquo;<b>(</b>&rsquo; exp &lsquo;<b>)</b>&rsquo;
562
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diff changeset
1135 </pre>
371
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diff changeset
1136
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diff changeset
1137 <p>
464
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diff changeset
1138 Numerals and literal strings are explained in <a href="#lex">Lexical Conventions</a>;
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parents: 429
diff changeset
1139 variables are explained in <a href="#vars">Variables</a>;
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diff changeset
1140 function definitions are explained in <a href="#fn_def">Function Definitions</a>;
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diff changeset
1141 function calls are explained in <a href="#fn_calls">Function Calls</a>;
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diff changeset
1142 table constructors are explained in <a href="#constructors">Table Constructors</a>.
371
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1143 Vararg expressions,
562
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1144 denoted by three dots ('<code>...</code>'), can only be used when
371
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1145 directly inside a vararg function;
464
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diff changeset
1146 they are explained in <a href="#fn_def">Function Definitions</a>.
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diff changeset
1147
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diff changeset
1148
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diff changeset
1149 <p>
eddf7c73373b fix references in the manual
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diff changeset
1150 Binary operators comprise arithmetic operators (see <a href="#arithmetic">Arithmetic Operators</a>),
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parents: 429
diff changeset
1151 relational operators (see <a href="#relational">Relational Operators</a>), logical operators (see <a href="#logical_ops">Logical Operators</a>),
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diff changeset
1152 and the concatenation operator (see <a href="#concatenation">Concatenation</a>).
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diff changeset
1153 Unary operators comprise the unary minus (see <a href="#arithmetic">Arithmetic Operators</a>),
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parents: 429
diff changeset
1154 the unary logical <b>not</b> (see <a href="#logical_ops">Logical Operators</a>),
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diff changeset
1155 and the unary <em>length operator</em> (see <a href="#length">The Length Operator</a>).
371
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parents:
diff changeset
1156
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parents:
diff changeset
1157
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parents:
diff changeset
1158 <p>
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diff changeset
1159 Both function calls and vararg expressions can result in multiple values.
464
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diff changeset
1160 If a function call is used as a statement (see <a href="#fn_stmt">Function Calls as Statements</a>),
371
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diff changeset
1161 then its return list is adjusted to zero elements,
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diff changeset
1162 thus discarding all returned values.
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diff changeset
1163 If an expression is used as the last (or the only) element
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diff changeset
1164 of a list of expressions,
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diff changeset
1165 then no adjustment is made
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diff changeset
1166 (unless the expression is enclosed in parentheses).
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1167 In all other contexts,
395
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diff changeset
1168 Luan adjusts the result list to one element,
371
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diff changeset
1169 either discarding all values except the first one
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1170 or adding a single <b>nil</b> if there are no values.
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parents:
diff changeset
1171
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parents:
diff changeset
1172
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parents:
diff changeset
1173 <p>
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parents:
diff changeset
1174 Here are some examples:
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1175
562
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diff changeset
1176 <pre>
371
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parents:
diff changeset
1177 f() -- adjusted to 0 results
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diff changeset
1178 g(f(), x) -- f() is adjusted to 1 result
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diff changeset
1179 g(x, f()) -- g gets x plus all results from f()
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parents:
diff changeset
1180 a,b,c = f(), x -- f() is adjusted to 1 result (c gets nil)
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parents:
diff changeset
1181 a,b = ... -- a gets the first vararg parameter, b gets
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parents:
diff changeset
1182 -- the second (both a and b can get nil if there
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parents:
diff changeset
1183 -- is no corresponding vararg parameter)
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parents:
diff changeset
1184
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1185 a,b,c = x, f() -- f() is adjusted to 2 results
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1186 a,b,c = f() -- f() is adjusted to 3 results
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1187 return f() -- returns all results from f()
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1188 return ... -- returns all received vararg parameters
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1189 return x,y,f() -- returns x, y, and all results from f()
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1190 {f()} -- creates a list with all results from f()
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1191 {...} -- creates a list with all vararg parameters
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1192 {f(), nil} -- f() is adjusted to 1 result
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1193 </pre>
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1194
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1195 <p>
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1196 Any expression enclosed in parentheses always results in only one value.
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1197 Thus,
562
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1198 <code>(f(x,y,z))</code> is always a single value,
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diff changeset
1199 even if <code>f</code> returns several values.
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1200 (The value of <code>(f(x,y,z))</code> is the first value returned by <code>f</code>
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1201 or <b>nil</b> if <code>f</code> does not return any values.)
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diff changeset
1202
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diff changeset
1203
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diff changeset
1204
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1205 <h4 heading><a name="arithmetic">Arithmetic Operators</a></h4>
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1206
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1207 <p>
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1208 Luan supports the following arithmetic operators:
371
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1209
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1210 <ul>
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1211 <li><b><code>+</code>: </b>addition</li>
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1212 <li><b><code>-</code>: </b>subtraction</li>
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1213 <li><b><code>*</code>: </b>multiplication</li>
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1214 <li><b><code>/</code>: </b>division</li>
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1215 <li><b><code>%</code>: </b>modulo</li>
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1216 <li><b><code>^</code>: </b>exponentiation</li>
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1217 <li><b><code>-</code>: </b>unary minus</li>
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1218 </ul>
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diff changeset
1219
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1220 <p>
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1221 Addition, subtraction, multiplication, division, and unary minus are the same as these operators in Java. Exponentiation uses Java's <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Math.html#pow(double,%20double)">Math.pow</a> function.
371
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1222
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diff changeset
1223 <p>
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diff changeset
1224 Modulo is defined as the remainder of a division
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1225 that rounds the quotient towards minus infinite (floor division).
395
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1226 (The Java modulo operator is not used.)
371
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diff changeset
1227
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diff changeset
1228
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1229
562
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1230 <h4 heading><a name="conversions">Coercions and Conversions</a></h4>
396
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1231
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diff changeset
1232 <p>
465
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diff changeset
1233 Luan generally avoids automatic conversions.
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1234 String concatenation automatically converts all of its arguments to strings.
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diff changeset
1235
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diff changeset
1236 <p>
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diff changeset
1237 Luan provides library functions for explicit type conversions.
371
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1238
396
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diff changeset
1239
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diff changeset
1240
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diff changeset
1241
562
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diff changeset
1242 <h4 heading><a name="relational">Relational Operators</a></h4>
396
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1243
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1244 <p>
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1245 Luan supports the following relational operators:
371
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1246
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diff changeset
1247 <ul>
562
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1248 <li><b><code>==</code>: </b>equality</li>
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1249 <li><b><code>~=</code>: </b>inequality</li>
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diff changeset
1250 <li><b><code>&lt;</code>: </b>less than</li>
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diff changeset
1251 <li><b><code>&gt;</code>: </b>greater than</li>
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diff changeset
1252 <li><b><code>&lt;=</code>: </b>less or equal</li>
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1253 <li><b><code>&gt;=</code>: </b>greater or equal</li>
371
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diff changeset
1254 </ul><p>
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parents:
diff changeset
1255 These operators always result in <b>false</b> or <b>true</b>.
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diff changeset
1256
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1257
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1258 <p>
562
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diff changeset
1259 Equality (<code>==</code>) first compares the type of its operands.
371
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diff changeset
1260 If the types are different, then the result is <b>false</b>.
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1261 Otherwise, the values of the operands are compared.
396
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diff changeset
1262 Strings, numbers, and binary values are compared in the obvious way (by value).
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diff changeset
1263
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diff changeset
1264 <p>
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diff changeset
1265 Tables
371
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diff changeset
1266 are compared by reference:
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diff changeset
1267 two objects are considered equal only if they are the same object.
396
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diff changeset
1268 Every time you create a new table,
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diff changeset
1269 it is different from any previously existing table.
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diff changeset
1270 Closures are also compared by reference.
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diff changeset
1271
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diff changeset
1272 <p>
417
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parents: 396
diff changeset
1273 You can change the way that Luan compares tables
464
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diff changeset
1274 by using the "eq" metamethod (see <a href="#meta">Metatables and Metamethods</a>).
371
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1275
396
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diff changeset
1276 <p>
562
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diff changeset
1277 Java values are compared for equality with the Java <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#equals(java.lang.Object)"><code>equals</code></a> method.
371
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diff changeset
1278
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parents:
diff changeset
1279 <p>
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parents:
diff changeset
1280 Equality comparisons do not convert strings to numbers
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diff changeset
1281 or vice versa.
562
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diff changeset
1282 Thus, <code>"0"==0</code> evaluates to <b>false</b>,
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diff changeset
1283 and <code>t[0]</code> and <code>t["0"]</code> denote different
371
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diff changeset
1284 entries in a table.
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diff changeset
1285
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parents:
diff changeset
1286
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diff changeset
1287 <p>
562
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diff changeset
1288 The operator <code>~=</code> is exactly the negation of equality (<code>==</code>).
371
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diff changeset
1289
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parents:
diff changeset
1290
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1291 <p>
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diff changeset
1292 The order operators work as follows.
396
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diff changeset
1293
371
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1294 If both arguments are numbers,
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diff changeset
1295 then they are compared following
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diff changeset
1296 the usual rule for binary operations.
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diff changeset
1297 Otherwise, if both arguments are strings,
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diff changeset
1298 then their values are compared according to the current locale.
396
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diff changeset
1299 Otherwise, Luan tries to call the "lt" or the "le"
464
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diff changeset
1300 metamethod (see <a href="#meta">Metatables and Metamethods</a>).
562
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diff changeset
1301 A comparison <code>a &gt; b</code> is translated to <code>b &lt; a</code>
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1302 and <code>a &gt;= b</code> is translated to <code>b &lt;= a</code>.
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diff changeset
1303
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diff changeset
1304
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diff changeset
1305
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diff changeset
1306
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diff changeset
1307
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diff changeset
1308 <h4 heading><a name="logical_ops">Logical Operators</a></h4>
396
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1309
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1310 <p>
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1311 The logical operators in Luan are
371
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1312 <b>and</b>, <b>or</b>, and <b>not</b>.
396
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diff changeset
1313 The <b>and</b> and <b>or</b> operators consider both <b>false</b> and <b>nil</b> as false
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diff changeset
1314 and anything else as true.
464
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diff changeset
1315 Like the control structures (see <a href="#control">Control Structures</a>),
396
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1316 the <b>not</b> operator requires a boolean value.
371
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diff changeset
1317
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diff changeset
1318 <p>
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diff changeset
1319 The negation operator <b>not</b> always returns <b>false</b> or <b>true</b>.
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1320 The conjunction operator <b>and</b> returns its first argument
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diff changeset
1321 if this value is <b>false</b> or <b>nil</b>;
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1322 otherwise, <b>and</b> returns its second argument.
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diff changeset
1323 The disjunction operator <b>or</b> returns its first argument
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diff changeset
1324 if this value is different from <b>nil</b> and <b>false</b>;
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1325 otherwise, <b>or</b> returns its second argument.
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diff changeset
1326 Both <b>and</b> and <b>or</b> use short-circuit evaluation;
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diff changeset
1327 that is,
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diff changeset
1328 the second operand is evaluated only if necessary.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1329 Here are some examples:
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diff changeset
1330
562
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diff changeset
1331 <pre>
371
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diff changeset
1332 10 or 20 --&gt; 10
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1333 10 or error() --&gt; 10
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diff changeset
1334 nil or "a" --&gt; "a"
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diff changeset
1335 nil and 10 --&gt; nil
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1336 false and error() --&gt; false
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diff changeset
1337 false and nil --&gt; false
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diff changeset
1338 false or nil --&gt; nil
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1339 10 and 20 --&gt; 20
562
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diff changeset
1340 </pre>
396
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diff changeset
1341
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diff changeset
1342 <p>
371
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diff changeset
1343 (In this manual,
562
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diff changeset
1344 <code>--&gt;</code> indicates the result of the preceding expression.)
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diff changeset
1345
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diff changeset
1346
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diff changeset
1347
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diff changeset
1348 <h4 heading><a name="concatenation">Concatenation</a></h4>
396
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1349
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diff changeset
1350 <p>
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diff changeset
1351 The string concatenation operator in Luan is
562
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diff changeset
1352 denoted by two dots ('<code>..</code>').
396
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1353 All operands are converted to strings.
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diff changeset
1354
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diff changeset
1355
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diff changeset
1356
562
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diff changeset
1357 <h4 heading><a name="length">The Length Operator</a></h4>
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diff changeset
1358
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diff changeset
1359 <p>
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diff changeset
1360 The length operator is denoted by the unary prefix operator <code>#</code>.
396
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diff changeset
1361 The length of a string is its number of characters.
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diff changeset
1362 The length of a binary is its number of bytes.
371
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1363
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diff changeset
1364
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diff changeset
1365 <p>
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1366 A program can modify the behavior of the length operator for
562
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diff changeset
1367 any table through the <code>__len</code> metamethod (see <a href="#meta">Metatables and Metamethods</a>).
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diff changeset
1368
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diff changeset
1369
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diff changeset
1370 <p>
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diff changeset
1371 Unless a <code>__len</code> metamethod is given,
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diff changeset
1372 the length of a table <code>t</code> is defined
396
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1373 as the number of elements in <em>sequence</em>,
371
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1374 that is,
396
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diff changeset
1375 the size of the set of its positive numeric keys is equal to <em>{1..n}</em>
371
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1376 for some non-negative integer <em>n</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1377 In that case, <em>n</em> is its length.
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diff changeset
1378 Note that a table like
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1379
562
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diff changeset
1380 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1381 {10, 20, nil, 40}
562
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diff changeset
1382 </pre>
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diff changeset
1383
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diff changeset
1384 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
1385 has a length of <code>2</code>, because that is the last key in sequence.
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diff changeset
1386
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parents: 556
diff changeset
1387
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parents: 556
diff changeset
1388
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parents: 556
diff changeset
1389
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diff changeset
1390
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diff changeset
1391 <h4 heading><a name="precedence">Precedence</a></h4>
396
ba8b0aae6453 work on manual;
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diff changeset
1392
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diff changeset
1393 <p>
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diff changeset
1394 Operator precedence in Luan follows the table below,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1395 from lower to higher priority:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1396
562
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diff changeset
1397 <pre>
371
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diff changeset
1398 or
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parents:
diff changeset
1399 and
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parents:
diff changeset
1400 &lt; &gt; &lt;= &gt;= ~= ==
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parents:
diff changeset
1401 ..
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diff changeset
1402 + -
396
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parents: 395
diff changeset
1403 * / %
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parents: 395
diff changeset
1404 unary operators (not # -)
371
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diff changeset
1405 ^
562
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diff changeset
1406 </pre>
396
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diff changeset
1407
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diff changeset
1408 <p>
371
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diff changeset
1409 As usual,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1410 you can use parentheses to change the precedences of an expression.
562
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diff changeset
1411 The concatenation ('<code>..</code>') and exponentiation ('<code>^</code>')
371
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diff changeset
1412 operators are right associative.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1413 All other binary operators are left associative.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1414
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1415
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1416
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1417
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1418
562
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diff changeset
1419 <h4 heading><a name="constructors">Table Constructors</a></h4>
396
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diff changeset
1420
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diff changeset
1421 <p>
371
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diff changeset
1422 Table constructors are expressions that create tables.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1423 Every time a constructor is evaluated, a new table is created.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1424 A constructor can be used to create an empty table
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1425 or to create a table and initialize some of its fields.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1426 The general syntax for constructors is
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parents:
diff changeset
1427
562
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diff changeset
1428 <pre>
604
b73f005f3735 table constructor now uses end_of_line as a delimiter
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parents: 589
diff changeset
1429 tableconstructor ::= &lsquo;<b>{</b>&rsquo; fieldlist &lsquo;<b>}</b>&rsquo;
b73f005f3735 table constructor now uses end_of_line as a delimiter
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parents: 589
diff changeset
1430 fieldlist ::= [field] {fieldsep [field]}
371
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parents:
diff changeset
1431 field ::= &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo; &lsquo;<b>=</b>&rsquo; exp | Name &lsquo;<b>=</b>&rsquo; exp | exp
604
b73f005f3735 table constructor now uses end_of_line as a delimiter
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parents: 589
diff changeset
1432 fieldsep ::= &lsquo;<b>,</b>&rsquo; | &lsquo;<b>;</b>&rsquo; | <b>end_of_line</b>
562
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diff changeset
1433 </pre>
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parents: 556
diff changeset
1434
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diff changeset
1435 <p>
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parents: 556
diff changeset
1436 Each field of the form <code>[exp1] = exp2</code> adds to the new table an entry
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parents: 556
diff changeset
1437 with key <code>exp1</code> and value <code>exp2</code>.
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diff changeset
1438 A field of the form <code>name = exp</code> is equivalent to
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diff changeset
1439 <code>["name"] = exp</code>.
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diff changeset
1440 Finally, fields of the form <code>exp</code> are equivalent to
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diff changeset
1441 <code>[i] = exp</code>, where <code>i</code> are consecutive integers
371
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parents:
diff changeset
1442 starting with 1.
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parents:
diff changeset
1443 Fields in the other formats do not affect this counting.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1444 For example,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1445
562
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diff changeset
1446 <pre>
371
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parents:
diff changeset
1447 a = { [f(1)] = g; "x", "y"; x = 1, f(x), [30] = 23; 45 }
562
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diff changeset
1448 </pre>
396
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diff changeset
1449
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diff changeset
1450 <p>
371
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parents:
diff changeset
1451 is equivalent to
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parents:
diff changeset
1452
562
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diff changeset
1453 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1454 do
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parents:
diff changeset
1455 local t = {}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1456 t[f(1)] = g
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1457 t[1] = "x" -- 1st exp
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parents:
diff changeset
1458 t[2] = "y" -- 2nd exp
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parents:
diff changeset
1459 t.x = 1 -- t["x"] = 1
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parents:
diff changeset
1460 t[3] = f(x) -- 3rd exp
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parents:
diff changeset
1461 t[30] = 23
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parents:
diff changeset
1462 t[4] = 45 -- 4th exp
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parents:
diff changeset
1463 a = t
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parents:
diff changeset
1464 end
562
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diff changeset
1465 </pre>
371
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parents:
diff changeset
1466
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parents:
diff changeset
1467 <p>
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parents:
diff changeset
1468 The order of the assignments in a constructor is undefined.
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parents:
diff changeset
1469 (This order would be relevant only when there are repeated keys.)
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parents:
diff changeset
1470
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parents:
diff changeset
1471
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parents:
diff changeset
1472 <p>
562
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diff changeset
1473 If the last field in the list has the form <code>exp</code>
371
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diff changeset
1474 and the expression is a function call or a vararg expression,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1475 then all values returned by this expression enter the list consecutively
464
eddf7c73373b fix references in the manual
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parents: 429
diff changeset
1476 (see <a href="#fn_calls">Function Calls</a>).
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1477
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1478
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1479 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1480 The field list can have an optional trailing separator,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1481 as a convenience for machine-generated code.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1482
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1483
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1484
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1485
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1486
562
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diff changeset
1487 <h4 heading><a name="fn_calls">Function Calls</a></h4>
417
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diff changeset
1488
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diff changeset
1489 <p>
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diff changeset
1490 A function call in Luan has the following syntax:
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diff changeset
1491
562
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diff changeset
1492 <pre>
371
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diff changeset
1493 functioncall ::= prefixexp args
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1494 </pre>
417
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parents: 396
diff changeset
1495
a40e99cf0b0b work on manual
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diff changeset
1496 <p>
371
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diff changeset
1497 In a function call,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1498 first prefixexp and args are evaluated.
685
1e4b0bc0202d update documentation
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parents: 642
diff changeset
1499 The value of prefixexp must have type <em>function</em>.
1e4b0bc0202d update documentation
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parents: 642
diff changeset
1500 This function is called
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1501 with the given arguments.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1502
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1503
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1504 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1505 Arguments have the following syntax:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1506
562
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diff changeset
1507 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1508 args ::= &lsquo;<b>(</b>&rsquo; [explist] &lsquo;<b>)</b>&rsquo;
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parents:
diff changeset
1509 args ::= tableconstructor
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1510 args ::= LiteralString
562
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diff changeset
1511 </pre>
417
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parents: 396
diff changeset
1512
a40e99cf0b0b work on manual
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diff changeset
1513 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1514 All argument expressions are evaluated before the call.
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1515 A call of the form <code>f{<em>fields</em>}</code> is
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1516 syntactic sugar for <code>f({<em>fields</em>})</code>;
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1517 that is, the argument list is a single new table.
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1518 A call of the form <code>f'<em>string</em>'</code>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1519 (or <code>f"<em>string</em>"</code> or <code>f[[<em>string</em>]]</code>)
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1520 is syntactic sugar for <code>f('<em>string</em>')</code>;
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1521 that is, the argument list is a single literal string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1522
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1523
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1524
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1525
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1526 <h4 heading><a name="fn_def">Function Definitions</a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1527
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1528 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1529 The syntax for function definition is
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1530
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1531 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1532 functiondef ::= <b>function</b> funcbody
1092
a26fbde7ee28 documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 1090
diff changeset
1533 funcbody ::= &lsquo;<b>(</b>&rsquo; [parlist] &lsquo;<b>)</b>&rsquo; block end_function
a26fbde7ee28 documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 1090
diff changeset
1534 end_function ::= <b>end_function</b> | <b>end</b>
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1535 </pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1536
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1537 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1538 The following syntactic sugar simplifies function definitions:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1539
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1540 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1541 stat ::= <b>function</b> funcname funcbody
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1542 stat ::= <b>local</b> <b>function</b> Name funcbody
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1543 funcname ::= Name {&lsquo;<b>.</b>&rsquo; Name} [&lsquo;<b>:</b>&rsquo; Name]
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1544 </pre>
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1545
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1546 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1547 The statement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1548
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1549 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1550 function f () <em>body</em> end
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1551 </pre>
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1552
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1553 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1554 translates to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1555
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1556 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1557 f = function () <em>body</em> end
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1558 </pre>
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1559
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1560 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1561 The statement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1562
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1563 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1564 function t.a.b.c.f () <em>body</em> end
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1565 </pre>
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1566
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1567 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1568 translates to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1569
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
1570 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1571 t.a.b.c.f = function () <em>body</em> end
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1572 </pre>
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1573
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1574 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1575 The statement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1576
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1577 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1578 local function f () <em>body</em> end
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1579 </pre>
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1580
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1581 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1582 translates to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1583
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1584 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1585 local f; f = function () <em>body</em> end
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1586 </pre>
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1587
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1588 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1589 not to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1590
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1591 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1592 local f = function () <em>body</em> end
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1593 </pre>
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1594
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1595 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1596 (This only makes a difference when the body of the function
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1597 contains references to <code>f</code>.)
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1598
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1599
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1600 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1601 A function definition is an executable expression,
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1602 whose value has type <em>function</em>.
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1603 When Luan precompiles a chunk,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1604 all its function bodies are precompiled too.
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1605 Then, whenever Luan executes the function definition,
562
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
1606 the function is <em>instantiated</em> (or <em>closed</em>).
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1607 This function instance (or <em>closure</em>)
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1608 is the final value of the expression.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1609
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1610
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1611 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1612 Parameters act as local variables that are
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1613 initialized with the argument values:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1614
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1615 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1616 parlist ::= namelist [&lsquo;<b>,</b>&rsquo; &lsquo;<b>...</b>&rsquo;] | &lsquo;<b>...</b>&rsquo;
562
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
1617 </pre>
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1618
a40e99cf0b0b work on manual
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diff changeset
1619 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1620 When a function is called,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1621 the list of arguments is adjusted to
1090
616761e0b9f6 update documentation for last change
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parents: 799
diff changeset
1622 the length of the list of parameters if the list is too short,
562
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
1623 unless the function is a <em>vararg function</em>,
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diff changeset
1624 which is indicated by three dots ('<code>...</code>')
371
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1625 at the end of its parameter list.
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1626 A vararg function does not adjust its argument list;
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diff changeset
1627 instead, it collects all extra arguments and supplies them
562
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diff changeset
1628 to the function through a <em>vararg expression</em>,
371
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diff changeset
1629 which is also written as three dots.
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diff changeset
1630 The value of this expression is a list of all actual extra arguments,
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diff changeset
1631 similar to a function with multiple results.
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diff changeset
1632 If a vararg expression is used inside another expression
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1633 or in the middle of a list of expressions,
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diff changeset
1634 then its return list is adjusted to one element.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1635 If the expression is used as the last element of a list of expressions,
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1636 then no adjustment is made
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diff changeset
1637 (unless that last expression is enclosed in parentheses).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1638
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1639
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1640 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1641 As an example, consider the following definitions:
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1642
562
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diff changeset
1643 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1644 function f(a, b) end
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diff changeset
1645 function g(a, b, ...) end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1646 function r() return 1,2,3 end
562
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diff changeset
1647 </pre>
417
a40e99cf0b0b work on manual
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diff changeset
1648
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diff changeset
1649 <p>
371
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diff changeset
1650 Then, we have the following mapping from arguments to parameters and
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parents:
diff changeset
1651 to the vararg expression:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1652
562
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diff changeset
1653 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1654 CALL PARAMETERS
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parents:
diff changeset
1655
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1656 f(3) a=3, b=nil
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1657 f(3, 4) a=3, b=4
1090
616761e0b9f6 update documentation for last change
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parents: 799
diff changeset
1658 f(3, 4, 5) runtime error
616761e0b9f6 update documentation for last change
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parents: 799
diff changeset
1659 f(r(), 10) runtime error
616761e0b9f6 update documentation for last change
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parents: 799
diff changeset
1660 f(r()) runtime error
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1661
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1662 g(3) a=3, b=nil, ... --&gt; (nothing)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1663 g(3, 4) a=3, b=4, ... --&gt; (nothing)
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parents:
diff changeset
1664 g(3, 4, 5, 8) a=3, b=4, ... --&gt; 5 8
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1665 g(5, r()) a=5, b=1, ... --&gt; 2 3
562
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diff changeset
1666 </pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1667
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1668 <p>
464
eddf7c73373b fix references in the manual
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diff changeset
1669 Results are returned using the <b>return</b> statement (see <a href="#control">Control Structures</a>).
371
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diff changeset
1670 If control reaches the end of a function
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1671 without encountering a <b>return</b> statement,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1672 then the function returns with no results.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1673
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1674
562
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diff changeset
1675 <h4 heading><a name="template_expr">Template Expressions</a></h4>
465
47c7de1f2322 documentation work
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parents: 464
diff changeset
1676
47c7de1f2322 documentation work
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diff changeset
1677 <p>Luan template expression are based on <a href="http://en.wikipedia.org/wiki/JavaServer_Pages">JSP</a>. Template expressions return multiple values. Here is an example:</p>
47c7de1f2322 documentation work
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diff changeset
1678
562
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diff changeset
1679 <pre><%=Html.encode[[
465
47c7de1f2322 documentation work
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parents: 464
diff changeset
1680 local name = "Bob"
469
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diff changeset
1681 write( %>Hello <%= name %>!<% )
562
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
1682 ]]%></pre>
465
47c7de1f2322 documentation work
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diff changeset
1683
47c7de1f2322 documentation work
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diff changeset
1684 <p>This is equivalent to the code:</p>
47c7de1f2322 documentation work
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parents: 464
diff changeset
1685
562
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
1686 <pre>
465
47c7de1f2322 documentation work
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parents: 464
diff changeset
1687 local name = "Bob"
47c7de1f2322 documentation work
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parents: 464
diff changeset
1688 write( "Hello ", name, "!" )
562
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
1689 </pre>
465
47c7de1f2322 documentation work
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parents: 464
diff changeset
1690
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
1691 <p>The strings in template expressions may be multiple lines.</p>
47c7de1f2322 documentation work
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parents: 464
diff changeset
1692
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1693
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diff changeset
1694
562
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diff changeset
1695 <h3 heading><a name="visibility">Visibility Rules</a></h3>
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1696
a40e99cf0b0b work on manual
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diff changeset
1697 <p>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1698 Luan is a lexically scoped language.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1699 The scope of a local variable begins at the first statement after
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1700 its declaration and lasts until the last non-void statement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1701 of the innermost block that includes the declaration.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1702 Consider the following example:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1703
562
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parents: 556
diff changeset
1704 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1705 x = 10 -- global variable
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1706 do -- new block
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1707 local x = x -- new 'x', with value 10
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1708 print(x) --&gt; 10
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1709 x = x+1
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1710 do -- another block
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1711 local x = x+1 -- another 'x'
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1712 print(x) --&gt; 12
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1713 end
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parents:
diff changeset
1714 print(x) --&gt; 11
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1715 end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1716 print(x) --&gt; 10 (the global one)
562
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diff changeset
1717 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1718
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1719 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1720 Notice that, in a declaration like <code>local x = x</code>,
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1721 the new <code>x</code> being declared is not in scope yet,
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1722 and so the second <code>x</code> refers to the outside variable.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1723
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1724
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1725 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1726 Because of the lexical scoping rules,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1727 local variables can be freely accessed by functions
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1728 defined inside their scope.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1729 A local variable used by an inner function is called
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1730 an <em>upvalue</em>, or <em>external local variable</em>,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1731 inside the inner function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1732
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1733
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1734 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1735 Notice that each execution of a <b>local</b> statement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1736 defines new local variables.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1737 Consider the following example:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1738
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1739 <pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1740 a = {}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1741 local x = 20
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1742 for i=1,10 do
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1743 local y = 0
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1744 a[i] = function () y=y+1; return x+y end
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parents:
diff changeset
1745 end
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1746 </pre>
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1747
a40e99cf0b0b work on manual
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diff changeset
1748 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1749 The loop creates ten closures
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1750 (that is, ten instances of the anonymous function).
562
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
1751 Each of these closures uses a different <code>y</code> variable,
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diff changeset
1752 while all of them share the same <code>x</code>.
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parents: 556
diff changeset
1753
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1754
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1755
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1756
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parents: 556
diff changeset
1757
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
1758 <h2 heading><a name="libs">Standard Libraries</a></h2>
468
9b51e2413cab documentation
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parents: 465
diff changeset
1759
9b51e2413cab documentation
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parents: 465
diff changeset
1760 <p>
9b51e2413cab documentation
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parents: 465
diff changeset
1761 The standard Luan libraries provide useful functions
9b51e2413cab documentation
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parents: 465
diff changeset
1762 that are implemented both in Java and in Luan itself.
9b51e2413cab documentation
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parents: 465
diff changeset
1763 How each function is implemented shouldn't matter to the user.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1764 Some of these functions provide essential services to the language
562
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parents: 556
diff changeset
1765 (e.g., <a href="#Luan.type"><code>type</code></a> and <a href="#Luan.get_metatable"><code>get_metatable</code></a>);
468
9b51e2413cab documentation
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parents: 465
diff changeset
1766 others provide access to "outside" services (e.g., I/O).
9b51e2413cab documentation
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diff changeset
1767
9b51e2413cab documentation
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parents: 465
diff changeset
1768
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
1769 <h3 heading><a name="default_lib">Default Environment</a></h3>
468
9b51e2413cab documentation
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parents: 465
diff changeset
1770
9b51e2413cab documentation
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parents: 465
diff changeset
1771 <p>
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diff changeset
1772 These are provided by default as local variables for any Luan code as described in <a href="#env">Environments</a>.
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1773
470
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1774
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1775 <h4 heading><a name="require"><code>java ()</code></a></h4>
470
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1776
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1777 <p>
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diff changeset
1778 This function enables Java in the current chunk if that chunk has permission to use Java. If the chunk doesn't have permission to use Java, then an error is thrown.
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diff changeset
1779
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1780
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1781 <h4 heading><a name="require"><code>require (mod_uri)</code></a></h4>
470
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1782
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1783 <p>
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1784 Example use:
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1785
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1786 <pre>
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1787 local Table = require "luan:Table.luan"
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1788 </pre>
470
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1789
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1790 <p>
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1791 Could be defined as:
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1792
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1793 <pre>
470
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1794 local function require(mod_name)
476
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diff changeset
1795 return <a href="#Package.load">Package.load</a>(mod_name) or <a href="#Luan.error">Luan.error</a>("module '"..mod_name.."' not found")
470
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1796 end
562
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1797 </pre>
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1798
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1799
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1800 <h3 heading><a name="luan_lib">Basic Functions</a></h3>
470
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1801
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1802 <p>
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diff changeset
1803 Include this library by:
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1804
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1805 <pre>
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1806 local Luan = require "luan:Luan.luan"
562
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1807 </pre>
470
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1808
476
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diff changeset
1809 <p>
470
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1810 The basic library provides basic functions to Luan that don't depend on other libaries.
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1811
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1812
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1813 <h4 heading><a name="Luan.do_file" href="#Luan.do_file"><code>Luan.do_file ([uri])</code></a></h4>
470
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1814
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1815 <p>
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1816 Could be defined as:
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1817
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1818 <pre>
470
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1819 function Luan.do_file(uri)
474
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1820 return <a href="#Luan.load_file">Luan.load_file</a>(uri)()
470
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1821 end
562
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1822 </pre>
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1823
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1824
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1825
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1826 <h4 heading><a name="Luan.error" href="#Luan.error"><code>Luan.error (message)</code></a></h4>
470
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diff changeset
1827
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1828 <p>
482
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diff changeset
1829 Throws an error containing the message.
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diff changeset
1830
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1831 <p>
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diff changeset
1832 Could be defined as:
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1833
562
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1834 <pre>
482
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diff changeset
1835 function Luan.error(message)
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diff changeset
1836 <a href="#Luan.new_error">Luan.new_error</a>(message).throw()
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1837 end
562
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1838 </pre>
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diff changeset
1839
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diff changeset
1840
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diff changeset
1841
695
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1842 <h4 heading><a name="Luan.eval" href="#Luan.eval"><code>Luan.eval (text [, source_name])</code></a></h4>
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diff changeset
1843
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diff changeset
1844 <p>
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diff changeset
1845 Evaluates <code>text</code> as a Luan expression.
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diff changeset
1846
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diff changeset
1847 <p>
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diff changeset
1848 Could be defined as:
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diff changeset
1849
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diff changeset
1850 <pre>
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diff changeset
1851 function Luan.eval(text,source_name)
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diff changeset
1852 return Luan.load( "return "..text, source_name or "eval" )()
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1853 end
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diff changeset
1854 </pre>
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diff changeset
1855
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diff changeset
1856
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diff changeset
1857
642
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diff changeset
1858 <h4 heading><a name="Luan.get_metatable" href="#Luan.get_metatable"><code>Luan.get_metatable (table)</code></a></h4>
562
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diff changeset
1859
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diff changeset
1860 <p>
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diff changeset
1861 If <code>table</code> does not have a metatable, returns <b>nil</b>.
371
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diff changeset
1862 Otherwise,
562
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diff changeset
1863 if the table's metatable has a <code>"__metatable"</code> field,
371
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1864 returns the associated value.
470
5627eb637eb4 documentation
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diff changeset
1865 Otherwise, returns the metatable of the given table.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1866
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parents:
diff changeset
1867
642
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diff changeset
1868 <h4 heading><a name="Luan.ipairs" href="#Luan.ipairs"><code>Luan.ipairs (t)</code></a></h4>
474
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diff changeset
1869
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diff changeset
1870 <p>
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diff changeset
1871 Returns an iterator function
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1872 so that the construction
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parents:
diff changeset
1873
562
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diff changeset
1874 <pre>
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diff changeset
1875 for i,v in ipairs(t) do <em>body</em> end
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diff changeset
1876 </pre>
474
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diff changeset
1877
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diff changeset
1878 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1879 will iterate over the key&ndash;value pairs
562
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diff changeset
1880 (<code>1,t[1]</code>), (<code>2,t[2]</code>), ...,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1881 up to the first nil value.
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parents:
diff changeset
1882
474
00646edc9d92 documentation
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parents: 472
diff changeset
1883 <p>
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parents: 472
diff changeset
1884 Could be defined as:
00646edc9d92 documentation
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diff changeset
1885
562
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diff changeset
1886 <pre>
474
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parents: 472
diff changeset
1887 function Luan.ipairs(t)
00646edc9d92 documentation
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parents: 472
diff changeset
1888 local i = 0
00646edc9d92 documentation
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diff changeset
1889 return function()
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diff changeset
1890 if i < #t then
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diff changeset
1891 i = i + 1
00646edc9d92 documentation
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diff changeset
1892 return i, t[i]
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diff changeset
1893 end
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diff changeset
1894 end
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diff changeset
1895 end
562
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diff changeset
1896 </pre>
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diff changeset
1897
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diff changeset
1898
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diff changeset
1899
695
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diff changeset
1900 <h4 heading><a name="Luan.load" href="#Luan.load"><code>Luan.load (text, source_name [, env])</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1901
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parents:
diff changeset
1902 <p>
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parents:
diff changeset
1903 Loads a chunk.
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parents:
diff changeset
1904
474
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diff changeset
1905 <p>
562
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diff changeset
1906 The <code>text</code> is compiled.
371
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diff changeset
1907 If there are no syntactic errors,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1908 returns the compiled chunk as a function;
474
00646edc9d92 documentation
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diff changeset
1909 otherwise, throws an error.
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diff changeset
1910
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diff changeset
1911 <p>
562
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diff changeset
1912 The <code>source_name</code> parameter is a string saying where the text came from. It is used to produce error messages.
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diff changeset
1913
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diff changeset
1914 <p>
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diff changeset
1915 If the <code>env</code> parameter is supplied, it becomes the <code>_ENV</code> of the chunk.
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diff changeset
1916
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diff changeset
1917
693
ca169567ce07 module URIs must now include ".luan"
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diff changeset
1918 <h4 heading><a name="Luan.load_file" href="#Luan.load_file"><code>Luan.load_file ([file_uri])</code></a></h4>
562
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diff changeset
1919
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diff changeset
1920 <p>
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diff changeset
1921 Similar to <a href="#Luan.load"><code>load</code></a>,
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diff changeset
1922 but gets the chunk from file <code>file_uri</code>
371
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diff changeset
1923 or from the standard input,
474
00646edc9d92 documentation
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diff changeset
1924 if no file uri is given.
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diff changeset
1925
00646edc9d92 documentation
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diff changeset
1926 <p>
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diff changeset
1927 Could be defined as:
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diff changeset
1928
562
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diff changeset
1929 <pre>
693
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diff changeset
1930 function Luan.load_file(file_uri)
474
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diff changeset
1931 file_uri = file_uri or "stdin:"
693
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diff changeset
1932 local f = Io.uri(file_uri)
474
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diff changeset
1933 f.exists() or <a href="#Luan.error">Luan.error</a>("file '"..file_uri.."' not found")
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diff changeset
1934 return <a href="#Luan.load">Luan.load</a>( f.read_text(), file_uri )
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1935 end
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1936 </pre>
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1937
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1938
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1939 <h4 heading><a name="Luan.new_error" href="#Luan.new_error"><code>Luan.new_error (message)</code></a></h4>
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1940
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1941 <p>
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1942 Creates a new error table containing the message assigned to "<code>message</code>". The error table also contains a <code>throw</code> function which throws the error. The table also contains a list of stack trace elements where each stack trace element is a table containing "<code>source</code>", "<code>line</code>", and possible "<code>call_to</code>". The table also has a metatable containing "<code>__to_string</code>" to render the error.
482
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1943
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1944 <p>
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diff changeset
1945 To print the current stack trace, you could do:
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1946
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1947 <pre>
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1948 Io.print( Luan.new_error "stack" )
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1949 </pre>
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1950
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1951
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1952 <h4 heading><a name="Luan.pairs" href="#Luan.pairs"><code>Luan.pairs (t)</code></a></h4>
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1953
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1954 <p>
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1955 If <code>t</code> has a metamethod <code>__pairs</code>,
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1956 calls it with <code>t</code> as argument and returns the
475
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1957 result from the call.
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1958
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1959
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1960 <p>
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1961 Otherwise,
475
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1962 returns a function
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1963 so that the construction
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1964
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1965 <pre>
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1966 for k,v in pairs(t) do <em>body</em> end
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1967 </pre>
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1968
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1969 <p>
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diff changeset
1970 will iterate over all key&ndash;value pairs of table <code>t</code>.
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1971
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1972
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1973
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1974 <h4 heading><a name="Luan.pcall" href="#Luan.pcall"><code>Luan.pcall (f [, arg1, &middot;&middot;&middot;])</code></a></h4>
562
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1975
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1976 <p>
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diff changeset
1977 Calls function <code>f</code> with
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1978 the given arguments in <em>protected mode</em>.
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diff changeset
1979 This means that any error inside&nbsp;<code>f</code> is not propagated;
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1980 instead, <code>pcall</code> catches the error
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1981 and returns a status code.
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1982 Its first result is the status code (a boolean),
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1983 which is true if the call succeeds without errors.
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1984 In such case, <code>pcall</code> also returns all results from the call,
371
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1985 after this first result.
562
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1986 In case of any error, <code>pcall</code> returns <b>false</b> plus the error.
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1987
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parents:
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1988
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1989
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1990
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
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1991 <p>
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diff changeset
1992 <hr><h3><a name="pdf-print"><code>print (&middot;&middot;&middot;)</code></a></h3>
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1993 Receives any number of arguments
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1994 and prints their values to <code>stdout</code>,
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parents:
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1995 using the <a href="#pdf-tostring"><code>tostring</code></a> function to convert each argument to a string.
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1996 <code>print</code> is not intended for formatted output,
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1997 but only as a quick way to show a value,
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diff changeset
1998 for instance for debugging.
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parents:
diff changeset
1999 For complete control over the output,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2000 use <a href="#pdf-string.format"><code>string.format</code></a> and <a href="#pdf-io.write"><code>io.write</code></a>.
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diff changeset
2001
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parents:
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2002
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2003
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2004 <h4 heading><a name="Luan.range" href="#Luan.range"><code>Luan.range (start, stop [, step])</code></a></h4>
476
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diff changeset
2005
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diff changeset
2006 <p>
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diff changeset
2007 Based on <a href="https://docs.python.org/2/library/functions.html#range">the Python range() function</a>, this lets one iterate through a sequence of numbers.
cd22e4694ea3 documentation
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diff changeset
2008
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diff changeset
2009 <p>
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diff changeset
2010 Example use:
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diff changeset
2011
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2012 <pre>
476
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diff changeset
2013 for i in range(1,10) do
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diff changeset
2014 Io.print("count up:",i)
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diff changeset
2015 end
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diff changeset
2016 for i in range(10,0,-1) do
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2017 Io.print("count down:",i)
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2018 end
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diff changeset
2019 </pre>
476
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diff changeset
2020
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diff changeset
2021 <p>
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diff changeset
2022 Could be defined as:
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diff changeset
2023
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diff changeset
2024 <pre>
476
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diff changeset
2025 function Luan.range(start, stop, step)
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diff changeset
2026 step = step or 1
478
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parents: 476
diff changeset
2027 step == 0 and <a href="#Luan.error">Luan.error</a> "bad argument #3 (step may not be zero)"
476
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diff changeset
2028 local i = start
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diff changeset
2029 return function()
cd22e4694ea3 documentation
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diff changeset
2030 if step > 0 and i <= stop or step < 0 and i >= stop then
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diff changeset
2031 local rtn = i
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diff changeset
2032 i = i + step
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diff changeset
2033 return rtn
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diff changeset
2034 end
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2035 end
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2036 end
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diff changeset
2037 </pre>
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diff changeset
2038
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2039
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diff changeset
2040
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diff changeset
2041 <h4 heading><a name="Luan.raw_equal" href="#Luan.raw_equal"><code>Luan.raw_equal (v1, v2)</code></a></h4>
562
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diff changeset
2042
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diff changeset
2043 <p>
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diff changeset
2044 Checks whether <code>v1</code> is equal to <code>v2</code>,
371
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diff changeset
2045 without invoking any metamethod.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2046 Returns a boolean.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2047
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2048
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parents:
diff changeset
2049
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diff changeset
2050 <h4 heading><a name="Luan.raw_get" href="#Luan.raw_get"><code>Luan.raw_get (table, index)</code></a></h4>
562
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diff changeset
2051
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diff changeset
2052 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2053 Gets the real value of <code>table[index]</code>,
371
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2054 without invoking any metamethod.
562
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diff changeset
2055 <code>table</code> must be a table;
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diff changeset
2056 <code>index</code> may be any value.
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diff changeset
2057
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diff changeset
2058
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2059
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diff changeset
2060 <h4 heading><a name="Luan.raw_len" href="#Luan.raw_len"><code>Luan.raw_len (v)</code></a></h4>
562
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diff changeset
2061
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diff changeset
2062 <p>
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diff changeset
2063 Returns the length of the object <code>v</code>,
371
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diff changeset
2064 which must be a table or a string,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2065 without invoking any metamethod.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2066 Returns an integer.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2067
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2068
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2069
642
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diff changeset
2070 <h4 heading><a name="Luan.raw_set" href="#Luan.raw_set"><code>Luan.raw_set (table, index, value)</code></a></h4>
562
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diff changeset
2071
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diff changeset
2072 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2073 Sets the real value of <code>table[index]</code> to <code>value</code>,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
2074 without invoking any metamethod.
562
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diff changeset
2075 <code>table</code> must be a table,
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diff changeset
2076 <code>index</code> any value different from <b>nil</b>,
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2077 and <code>value</code> any Lua value.
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2078
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2079
642
c4216a583de4 add links to functions in manual
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diff changeset
2080 <h4 heading><a name="Luan.set_metatable" href="#Luan.set_metatable"><code>Luan.set_metatable (table, metatable)</code></a></h4>
371
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parents:
diff changeset
2081
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parents:
diff changeset
2082 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2083 Sets the metatable for the given table.
562
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diff changeset
2084 If <code>metatable</code> is <b>nil</b>,
371
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2085 removes the metatable of the given table.
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diff changeset
2086 If the original metatable has a <code>"__metatable"</code> field,
371
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diff changeset
2087 raises an error.
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diff changeset
2088
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2089
1189
73d754b1889f add stringify
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diff changeset
2090 <h4 heading><a name="Luan.stringify" href="#Luan.stringify"><code>Luan.stringify (v [,strict])</code></a></h4>
73d754b1889f add stringify
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parents: 1164
diff changeset
2091
73d754b1889f add stringify
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diff changeset
2092 <p>
73d754b1889f add stringify
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diff changeset
2093 Receives a value of any type and converts it to a string that is a Luan expression. <code>strict</code> is a boolean. If <code>strict</code> is true then invalid types throw an error. If <code>strict</code> is false then invalid types are represented but the resulting expression is invalid. <code>strict</code> defaults to <b>true</b>.
73d754b1889f add stringify
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diff changeset
2094
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diff changeset
2095
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diff changeset
2096 <h4 heading><a name="Luan.to_string" href="#Luan.to_string"><code>Luan.to_string (v)</code></a></h4>
475
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diff changeset
2097
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diff changeset
2098 <p>
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diff changeset
2099 Receives a value of any type and
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diff changeset
2100 converts it to a string in a human-readable format.
475
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diff changeset
2101
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diff changeset
2102 <p>
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diff changeset
2103 If the metatable of <code>v</code> has a <code>"__to_string"</code> field,
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diff changeset
2104 then <code>to_string</code> calls the corresponding value
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diff changeset
2105 with <code>v</code> as argument,
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2106 and uses the result of the call as its result.
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diff changeset
2107
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diff changeset
2108
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diff changeset
2109
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2110 <h4 heading><a name="Luan.try" href="#Luan.try"><code>Luan.try (t, &middot;&middot;&middot;)</code></a></h4>
589
97c8ae330efe add varargs to Luan.try;
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2111
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2112 <p>
97c8ae330efe add varargs to Luan.try;
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diff changeset
2113 Implements try-catch as found in other languages where each block is in table <code>t</code>. <code>t[1]</code> is the "try" block. The <code>t.catch</code> and <code>t.finally</code> blocks are optional. Any extra arguments are passed to the "try" function. Returns the result of the "try" block or the "catch" block.
476
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diff changeset
2114
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diff changeset
2115 <p>
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diff changeset
2116 Example use:
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diff changeset
2117
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2118 <pre>
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diff changeset
2119 try {
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diff changeset
2120 function()
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diff changeset
2121 a_dangerous_fn()
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2122 end
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diff changeset
2123 catch = function(e)
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diff changeset
2124 -- handle error
702
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diff changeset
2125 end
476
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diff changeset
2126 finally = function()
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diff changeset
2127 -- clean up
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2128 end
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diff changeset
2129 }
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diff changeset
2130 </pre>
476
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diff changeset
2131
482
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diff changeset
2132 <p>
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parents: 479
diff changeset
2133 Could be defined as:
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diff changeset
2134
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diff changeset
2135 <pre>
482
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parents: 479
diff changeset
2136 function Luan.try(t)
7e9fcfbf22ec documentation
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parents: 479
diff changeset
2137 local r = { <a href="#Luan.pcall">Luan.pcall</a>(t[1]) }
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parents: 479
diff changeset
2138 if r[1] then
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parents: 479
diff changeset
2139 Table.remove(r,1)
7e9fcfbf22ec documentation
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parents: 479
diff changeset
2140 elseif t.catch ~= nil then
7e9fcfbf22ec documentation
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diff changeset
2141 r = { t.catch(r[2]) }
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diff changeset
2142 else
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diff changeset
2143 t.finally and t.finally()
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parents: 479
diff changeset
2144 r[2].throw()
7e9fcfbf22ec documentation
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diff changeset
2145 end
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diff changeset
2146 t.finally and t.finally()
7e9fcfbf22ec documentation
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diff changeset
2147 return Table.unpack(r)
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diff changeset
2148 end
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diff changeset
2149 </pre>
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diff changeset
2150
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diff changeset
2151
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diff changeset
2152 <h4 heading><a name="Luan.type" href="#Luan.type"><code>Luan.type (v)</code></a></h4>
475
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diff changeset
2153
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diff changeset
2154 <p>
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2155 Returns the type of its only argument, coded as a string.
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diff changeset
2156 The possible results of this function are
562
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diff changeset
2157 "<code>nil</code>" (a string, not the value <b>nil</b>),
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diff changeset
2158 "<code>number</code>",
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diff changeset
2159 "<code>string</code>",
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diff changeset
2160 "<code>binary</code>",
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diff changeset
2161 "<code>boolean</code>",
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diff changeset
2162 "<code>table</code>",
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diff changeset
2163 "<code>function</code>",
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diff changeset
2164 and "<code>java</code>".
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2165
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parents: 556
diff changeset
2166
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diff changeset
2167 <h4 heading><a name="Luan.values" href="#Luan.values"><code>Luan.values (&middot;&middot;&middot;)</code></a></h4>
476
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diff changeset
2168
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diff changeset
2169 <p>
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diff changeset
2170 Returns a function so that the construction
cd22e4694ea3 documentation
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parents: 475
diff changeset
2171
562
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diff changeset
2172 <pre>
1276
623dfe0e2e73 change Luan.values
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parents: 1272
diff changeset
2173 for i, v in Luan.values(&middot;&middot;&middot;) do <em>body</em> end
562
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diff changeset
2174 </pre>
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parents: 556
diff changeset
2175
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diff changeset
2176 <p>
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diff changeset
2177 will iterate over all values of <code>&middot;&middot;&middot;</code>.
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diff changeset
2178
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2179
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diff changeset
2180
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parents: 629
diff changeset
2181 <h4 heading><a name="Luan.VERSION" href="#Luan.VERSION"><code>Luan.VERSION</code></a></h4>
475
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diff changeset
2182
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parents: 474
diff changeset
2183 <p>
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parents:
diff changeset
2184 A global variable (not a function) that
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2185 holds a string containing the current interpreter version.
562
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diff changeset
2186 The current value of this variable is "<code><%=Luan.VERSION%></code>".
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diff changeset
2187
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2188
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2189
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2190
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2191
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diff changeset
2192
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2193 <h3 heading><a name="package_lib">Modules</a></h3>
476
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parents: 475
diff changeset
2194
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parents: 475
diff changeset
2195 <p>
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parents: 475
diff changeset
2196 Include this library by:
cd22e4694ea3 documentation
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parents: 475
diff changeset
2197
562
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diff changeset
2198 <pre>
693
ca169567ce07 module URIs must now include ".luan"
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parents: 685
diff changeset
2199 local Package = require "luan:Package.luan"
562
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diff changeset
2200 </pre>
371
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parents:
diff changeset
2201
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2202 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2203 The package library provides basic
476
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parents: 475
diff changeset
2204 facilities for loading modules in Luan.
cd22e4694ea3 documentation
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parents: 475
diff changeset
2205
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parents: 475
diff changeset
2206
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diff changeset
2207 <h4 heading><a name="Package.load" href="#Package.load"><code>Package.load (mod_uri)</code></a></h4>
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parents:
diff changeset
2208
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parents:
diff changeset
2209 <p>
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parents:
diff changeset
2210 Loads the given module.
562
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diff changeset
2211 The function starts by looking into the <a href="#Package.loaded"><code>Package.loaded</code></a> table
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diff changeset
2212 to determine whether <code>mod_uri</code> is already loaded.
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diff changeset
2213 If it is, then <code>Package.load</code> returns the value stored
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2214 at <code>Package.loaded[mod_uri]</code>.
476
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diff changeset
2215 Otherwise, it tries to load a new value for the module.
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diff changeset
2216
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diff changeset
2217 <p>
562
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diff changeset
2218 To load a new value, <code>Package.load</code> first checks if <code>mod_uri</code> starts with "<b>java:</b>". If yes, then this is a Java class which is loaded by special Java code.
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diff changeset
2219
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diff changeset
2220 <p>
799
9c13a15a4002 Package.load() now returns false instead of null, and caches the result. This cleans up the luan.isLocked issues.
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parents: 793
diff changeset
2221 Otherwise <code>Package.load</code> tries to read the text of the file referred to by <code>mod_uri</code>. If the file doesn't exist, then <code>Package.load</code> returns <b>false</b>. If the file exists, then its content is compiled into a chunk by calling <a href="#Luan.load"><code>Luan.load</code></a>. This chunk is run passing in <code>mod_uri</code> as an argument. The value returned by the chunk must not be <b>nil</b> and is loaded.
562
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diff changeset
2222
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diff changeset
2223 <p>
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diff changeset
2224 If a new value for the module successful loaded, then it is stored in <code>Package.loaded[mod_uri]</code>. The value is returned.
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diff changeset
2225
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parents: 556
diff changeset
2226
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diff changeset
2227
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diff changeset
2228
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diff changeset
2229 <h4 heading><a name="Package.loaded" href="#Package.loaded"><code>Package.loaded</code></a></h4>
562
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diff changeset
2230
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diff changeset
2231
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diff changeset
2232 <p>
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diff changeset
2233 A table used by <a href="#Package.load"><code>Package.load</code></a> to control which
371
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parents:
diff changeset
2234 modules are already loaded.
562
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diff changeset
2235 When you load a module <code>mod_uri</code> and
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diff changeset
2236 <code>Package.loaded[mod_uri]</code> is not <b>nil</b>,
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diff changeset
2237 <a href="#Package.load"><code>Package.load</code></a> simply returns the value stored there.
371
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diff changeset
2238
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2239
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2240 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
2241 This variable is only a reference to the real table;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
2242 assignments to this variable do not change the
562
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diff changeset
2243 table used by <a href="#Package.load"><code>Package.load</code></a>.
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diff changeset
2244
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diff changeset
2245
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diff changeset
2246
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diff changeset
2247
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diff changeset
2248
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diff changeset
2249
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diff changeset
2250 <h3 heading><a name="string_lib">String Manipulation</a></h3>
555
e25ba7a2e816 some String documentation and fixes
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diff changeset
2251
e25ba7a2e816 some String documentation and fixes
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diff changeset
2252 <p>
e25ba7a2e816 some String documentation and fixes
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diff changeset
2253 Include this library by:
e25ba7a2e816 some String documentation and fixes
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diff changeset
2254
562
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diff changeset
2255 <pre>
693
ca169567ce07 module URIs must now include ".luan"
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parents: 685
diff changeset
2256 local String = require "luan:String.luan"
562
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diff changeset
2257 </pre>
371
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diff changeset
2258
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2259 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2260 This library provides generic functions for string manipulation,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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2261 such as finding and extracting substrings, and pattern matching.
555
e25ba7a2e816 some String documentation and fixes
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diff changeset
2262 When indexing a string in Luan, the first character is at position&nbsp;1
e25ba7a2e816 some String documentation and fixes
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diff changeset
2263 (not at&nbsp;0, as in Java).
371
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diff changeset
2264 Indices are allowed to be negative and are interpreted as indexing backwards,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2265 from the end of the string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
2266 Thus, the last character is at position -1, and so on.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
2267
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
2268
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2269
642
c4216a583de4 add links to functions in manual
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diff changeset
2270 <h4 heading><a name="String.char" href="#String.char"><code>String.char (&middot;&middot;&middot;)</code></a></h4>
555
e25ba7a2e816 some String documentation and fixes
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diff changeset
2271
e25ba7a2e816 some String documentation and fixes
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diff changeset
2272 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
2273 Receives zero or more integers.
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diff changeset
2274 Returns a string with length equal to the number of arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2275 in which each character has the internal numerical code equal
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2276 to its corresponding argument.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2277
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2278
642
c4216a583de4 add links to functions in manual
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diff changeset
2279 <h4 heading><a name="String.concat" href="#String.concat"><code>String.concat (&middot;&middot;&middot;)</code></a></h4>
562
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diff changeset
2280
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diff changeset
2281 <p>
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diff changeset
2282 Concatenates the <a href="#Luan.to_string"><code>to_string</code></a> value of all arguments.
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diff changeset
2283
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diff changeset
2284
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2285
642
c4216a583de4 add links to functions in manual
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diff changeset
2286 <h4 heading><a name="String.encode" href="#String.encode"><code>String.encode (s)</code></a></h4>
562
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diff changeset
2287
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diff changeset
2288 <p>
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diff changeset
2289 Encodes argument <code>s</code> into a string that can be placed in quotes so as to return the original value of the string.
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diff changeset
2290
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parents: 556
diff changeset
2291
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2292
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2293
642
c4216a583de4 add links to functions in manual
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diff changeset
2294 <h4 heading><a name="String.find" href="#String.find"><code>String.find (s, pattern [, init [, plain]])</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
2295
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2296 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2297 Looks for the first match of
562
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2298 <code>pattern</code> (see <a href="http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html">Pattern</a>) in the string <code>s</code>.
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2299 If it finds a match, then <code>find</code> returns the indices of&nbsp;<code>s</code>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2300 where this occurrence starts and ends;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2301 otherwise, it returns <b>nil</b>.
562
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diff changeset
2302 A third, optional numerical argument <code>init</code> specifies
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2303 where to start the search;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2304 its default value is&nbsp;1 and can be negative.
562
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diff changeset
2305 A value of <b>true</b> as a fourth, optional argument <code>plain</code>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2306 turns off the pattern matching facilities,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2307 so the function does a plain "find substring" operation,
562
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diff changeset
2308 with no characters in <code>pattern</code> being considered magic.
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2309 Note that if <code>plain</code> is given, then <code>init</code> must be given as well.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2310
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2311 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2312 If the pattern has captures,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2313 then in a successful match
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2314 the captured values are also returned,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2315 after the two indices.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2316
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2317
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2318
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2319
642
c4216a583de4 add links to functions in manual
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parents: 629
diff changeset
2320 <h4 heading><a name="String.format" href="#String.format"><code>String.format (formatstring, &middot;&middot;&middot;)</code></a></h4>
371
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parents:
diff changeset
2321
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2322
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2323 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2324 Returns a formatted version of its variable number of arguments
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2325 following the description given in its first argument (which must be a string).
562
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parents: 556
diff changeset
2326 The format string follows the same rules as the Java function <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#format(java.lang.String,%20java.lang.Object...)"><code>String.format</code></a> because Luan calls this internally.
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2327
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2328 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2329 Note that Java's <code>String.format</code> is too stupid to convert between ints and floats, so you must provide the right kind of number.
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2330
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2331
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2332
642
c4216a583de4 add links to functions in manual
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parents: 629
diff changeset
2333 <h4 heading><a name="String.gmatch" href="#String.gmatch"><code>String.gmatch (s, pattern)</code></a></h4>
555
e25ba7a2e816 some String documentation and fixes
Franklin Schmidt <fschmidt@gmail.com>
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diff changeset
2334
e25ba7a2e816 some String documentation and fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 553
diff changeset
2335 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2336 Returns an iterator function that,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2337 each time it is called,
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2338 returns the next captures from <code>pattern</code> (see <a href="http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html">Pattern</a>)
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2339 over the string <code>s</code>.
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2340 If <code>pattern</code> specifies no captures,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2341 then the whole match is produced in each call.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2342
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2343
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2344 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2345 As an example, the following loop
562
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parents: 556
diff changeset
2346 will iterate over all the words from string <code>s</code>,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2347 printing one per line:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2348
562
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parents: 556
diff changeset
2349 <pre>
555
e25ba7a2e816 some String documentation and fixes
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parents: 553
diff changeset
2350 local s = "hello world from Lua"
e25ba7a2e816 some String documentation and fixes
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diff changeset
2351 for w in String.gmatch(s, [[\w+]]) do
e25ba7a2e816 some String documentation and fixes
Franklin Schmidt <fschmidt@gmail.com>
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diff changeset
2352 print(w)
e25ba7a2e816 some String documentation and fixes
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diff changeset
2353 end
562
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diff changeset
2354 </pre>
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parents: 556
diff changeset
2355
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2356 <p>
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parents: 556
diff changeset
2357 The next example collects all pairs <code>key=value</code> from the
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2358 given string into a table:
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parents:
diff changeset
2359
562
7cc9d4a53d3b remove SimplyHTML from documentation
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diff changeset
2360 <pre>
555
e25ba7a2e816 some String documentation and fixes
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parents: 553
diff changeset
2361 local t = {}
e25ba7a2e816 some String documentation and fixes
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parents: 553
diff changeset
2362 local s = "from=world, to=Lua"
e25ba7a2e816 some String documentation and fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 553
diff changeset
2363 for k, v in String.gmatch(s, [[(\w+)=(\w+)]]) do
e25ba7a2e816 some String documentation and fixes
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diff changeset
2364 t[k] = v
e25ba7a2e816 some String documentation and fixes
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diff changeset
2365 end
562
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diff changeset
2366 </pre>
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parents: 556
diff changeset
2367
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2368 <p>
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diff changeset
2369 For this function, a caret '<code>^</code>' at the start of a pattern does not
371
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parents:
diff changeset
2370 work as an anchor, as this would prevent the iteration.
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parents:
diff changeset
2371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2372
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2373
642
c4216a583de4 add links to functions in manual
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parents: 629
diff changeset
2374 <h4 heading><a name="String.gsub" href="#String.gsub"><code>String.gsub (s, pattern, repl [, n])</code></a></h4>
562
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diff changeset
2375
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diff changeset
2376 <p>
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diff changeset
2377 Returns a copy of <code>s</code>
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diff changeset
2378 in which all (or the first <code>n</code>, if given)
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2379 occurrences of the <code>pattern</code> (see <a href="http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html">Pattern</a>) have been
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2380 replaced by a replacement string specified by <code>repl</code>,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2381 which can be a string, a table, or a function.
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2382 <code>gsub</code> also returns, as its second value,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2383 the total number of matches that occurred.
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2384 The name <code>gsub</code> comes from <em>Global SUBstitution</em>.
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2385
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2386
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2387 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2388 If <code>repl</code> is a string, then its value is used for replacement.
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2389 The character&nbsp;<code>\</code> works as an escape character.
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2390 Any sequence in <code>repl</code> of the form <code>$<em>d</em></code>,
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2391 with <em>d</em> between 1 and 9,
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2392 stands for the value of the <em>d</em>-th captured substring.
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2393 The sequence <code>$0</code> stands for the whole match.
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2394
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2395
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2396 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2397 If <code>repl</code> is a table, then the table is queried for every match,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2398 using the first capture as the key.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2399
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2400
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2401 <p>
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2402 If <code>repl</code> is a function, then this function is called every time a
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2403 match occurs, with all captured substrings passed as arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2404 in order.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2405
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2406
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2407 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2408 In any case,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2409 if the pattern specifies no captures,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2410 then it behaves as if the whole pattern was inside a capture.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2411
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2412
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2413 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2414 If the value returned by the table query or by the function call
555
e25ba7a2e816 some String documentation and fixes
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parents: 553
diff changeset
2415 is not <b>nil</b>,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2416 then it is used as the replacement string;
555
e25ba7a2e816 some String documentation and fixes
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parents: 553
diff changeset
2417 otherwise, if it is <b>nil</b>,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2418 then there is no replacement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2419 (that is, the original match is kept in the string).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2420
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2421
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2422 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2423 Here are some examples:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2424
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2425 <pre>
555
e25ba7a2e816 some String documentation and fixes
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parents: 553
diff changeset
2426 x = String.gsub("hello world", [[(\w+)]], "$1 $1")
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2427 --&gt; x="hello hello world world"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2428
555
e25ba7a2e816 some String documentation and fixes
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parents: 553
diff changeset
2429 x = String.gsub("hello world", [[\w+]], "$0 $0", 1)
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2430 --&gt; x="hello hello world"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2431
555
e25ba7a2e816 some String documentation and fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 553
diff changeset
2432 x = String.gsub("hello world from Luan", [[(\w+)\s*(\w+)]], "$2 $1")
e25ba7a2e816 some String documentation and fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 553
diff changeset
2433 --&gt; x="world hello Luan from"
e25ba7a2e816 some String documentation and fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 553
diff changeset
2434
e25ba7a2e816 some String documentation and fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 553
diff changeset
2435 x = String.gsub("4+5 = $return 4+5$", [[\$(.*?)\$]], function (s)
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2436 return load(s)()
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2437 end)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2438 --&gt; x="4+5 = 9"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2439
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2440 local t = {name="lua", version="5.3"}
555
e25ba7a2e816 some String documentation and fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 553
diff changeset
2441 x = String.gsub("$name-$version.tar.gz", [[\$(\w+)]], t)
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2442 --&gt; x="lua-5.3.tar.gz"
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2443 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2444
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2445
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2446
642
c4216a583de4 add links to functions in manual
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parents: 629
diff changeset
2447 <h4 heading><a name="String.literal" href="#String.literal"><code>String.literal (s)</code></a></h4>
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2448 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2449 Returns a string which matches the literal string <code>s</code> in a regular expression. This function is simply the Java method <a href="http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html#quote(java.lang.String)"><code>Pattern.quote</code></a>.
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2450
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2451
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2452 <h4 heading><a name="String.lower" href="#String.lower"><code>String.lower (s)</code></a></h4>
555
e25ba7a2e816 some String documentation and fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 553
diff changeset
2453 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2454 Receives a string and returns a copy of this string with all
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2455 uppercase letters changed to lowercase.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2456 All other characters are left unchanged.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2457
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2458
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2459
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2460
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2461 <h4 heading><a name="String.match" href="#String.match"><code>String.match (s, pattern [, init])</code></a></h4>
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2462
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2463 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2464 Looks for the first <em>match</em> of
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2465 <code>pattern</code> (see <a href="http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html">Pattern</a>) in the string <code>s</code>.
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2466 If it finds one, then <code>match</code> returns
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2467 the captures from the pattern;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2468 otherwise it returns <b>nil</b>.
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2469 If <code>pattern</code> specifies no captures,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2470 then the whole match is returned.
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2471 A third, optional numerical argument <code>init</code> specifies
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2472 where to start the search;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2473 its default value is&nbsp;1 and can be negative.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2474
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2475
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2476 <h4 heading><a name="String.matches" href="#String.matches"><code>String.matches (s, pattern)</code></a></h4>
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2477 <p>
629
35dde32c02ab change String.matches()
Franklin Schmidt <fschmidt@gmail.com>
parents: 626
diff changeset
2478 Returns a boolean indicating whether the <code>pattern</code> can be found in string <code>s</code>.
35dde32c02ab change String.matches()
Franklin Schmidt <fschmidt@gmail.com>
parents: 626
diff changeset
2479 This function is equivalent to
35dde32c02ab change String.matches()
Franklin Schmidt <fschmidt@gmail.com>
parents: 626
diff changeset
2480
35dde32c02ab change String.matches()
Franklin Schmidt <fschmidt@gmail.com>
parents: 626
diff changeset
2481 <pre>
35dde32c02ab change String.matches()
Franklin Schmidt <fschmidt@gmail.com>
parents: 626
diff changeset
2482 return String.match(s,pattern) ~= nil
35dde32c02ab change String.matches()
Franklin Schmidt <fschmidt@gmail.com>
parents: 626
diff changeset
2483 </pre>
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2484
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2485
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2486 <h4 heading><a name="String.rep" href="#String.rep"><code>String.rep (s, n [, sep])</code></a></h4>
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2487 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2488 Returns a string that is the concatenation of <code>n</code> copies of
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2489 the string <code>s</code> separated by the string <code>sep</code>.
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2490 The default value for <code>sep</code> is the empty string
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2491 (that is, no separator).
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2492 Returns the empty string if <code>n</code> is not positive.
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2493
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2494
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2495
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2496
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2497 <h4 heading><a name="String.reverse" href="#String.reverse"><code>String.reverse (s)</code></a></h4>
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2498 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2499 Returns a string that is the string <code>s</code> reversed.
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2500
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2501
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2502
1195
9a57f0b16c2b better String.split
Franklin Schmidt <fschmidt@gmail.com>
parents: 1189
diff changeset
2503 <h4 heading><a name="String.split" href="#String.match"><code>String.split (s, pattern [, limit])</code></a></h4>
9a57f0b16c2b better String.split
Franklin Schmidt <fschmidt@gmail.com>
parents: 1189
diff changeset
2504
9a57f0b16c2b better String.split
Franklin Schmidt <fschmidt@gmail.com>
parents: 1189
diff changeset
2505 <p>
9a57f0b16c2b better String.split
Franklin Schmidt <fschmidt@gmail.com>
parents: 1189
diff changeset
2506 Splits <code>s</code> using regex <code>pattern</code> and returns the results. If <code>limit</code> is positive, then only returns at most that many results. If <code>limit</code> is zero, then remove trailing empty results.
9a57f0b16c2b better String.split
Franklin Schmidt <fschmidt@gmail.com>
parents: 1189
diff changeset
2507
9a57f0b16c2b better String.split
Franklin Schmidt <fschmidt@gmail.com>
parents: 1189
diff changeset
2508
562
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2509
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2510 <h4 heading><a name="String.sub" href="#String.sub"><code>String.sub (s, i [, j])</code></a></h4>
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2511
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2512 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2513 Returns the substring of <code>s</code> that
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2514 starts at <code>i</code> and continues until <code>j</code>;
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2515 <code>i</code> and <code>j</code> can be negative.
7cc9d4a53d3b remove SimplyHTML from documentation
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parents: 556
diff changeset
2516 If <code>j</code> is absent, then it is assumed to be equal to -1
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2517 (which is the same as the string length).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
2518 In particular,
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2519 the call <code>string.sub(s,1,j)</code> returns a prefix of <code>s</code>
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2520 with length <code>j</code>,
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2521 and <code>string.sub(s, -i)</code> returns a suffix of <code>s</code>
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2522 with length <code>i</code>.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2523
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2524
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2525 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2526 If, after the translation of negative indices,
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2527 <code>i</code> is less than 1,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2528 it is corrected to 1.
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2529 If <code>j</code> is greater than the string length,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2530 it is corrected to that length.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2531 If, after these corrections,
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2532 <code>i</code> is greater than <code>j</code>,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2533 the function returns the empty string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2534
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2535
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2536
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2537 <h4 heading><a name="String.to_binary" href="#String.to_binary"><code>String.to_binary (s)</code></a></h4>
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2538
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2539 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2540 Converts a string to a binary by calling the Java method <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#getBytes()"><code>String.getBytes</code></a>.
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2541
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2542
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2543
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2544 <h4 heading><a name="String.to_number" href="#String.to_number"><code>String.to_number (s [, base])</code></a></h4>
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2545
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2546 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2547 When called with no <code>base</code>,
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2548 <code>to_number</code> tries to convert its argument to a number.
556
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2549 If the argument is
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2550 a string convertible to a number,
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2551 then <code>to_number</code> returns this number;
556
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2552 otherwise, it returns <b>nil</b>.
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2553
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2554 The conversion of strings can result in integers or floats.
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2555
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2556
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2557 <p>
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2558 When called with <code>base</code>,
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2559 then <code>s</code> must be a string to be interpreted as
556
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2560 an integer numeral in that base.
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2561 In bases above&nbsp;10, the letter '<code>A</code>' (in either upper or lower case)
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2562 represents&nbsp;10, '<code>B</code>' represents&nbsp;11, and so forth,
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2563 with '<code>Z</code>' representing 35.
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2564 If the string <code>s</code> is not a valid numeral in the given base,
556
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2565 the function returns <b>nil</b>.
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2566
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2567
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2568
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2569 <h4 heading><a name="String.trim" href="#String.trim"><code>String.trim (s)</code></a></h4>
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2570
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2571 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2572 Removes the leading and trailing whitespace by calling the Java method <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#trim()"><code>String.trim</code></a>.
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2573
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2574
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2575
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2576
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2577 <h4 heading><a name="String.unicode" href="#String.unicode"><code>String.unicode (s [, i [, j]])</code></a></h4>
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2578
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2579 <p>
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2580 Returns the internal numerical codes of the characters <code>s[i]</code>,
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2581 <code>s[i+1]</code>, ..., <code>s[j]</code>.
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2582 The default value for <code>i</code> is&nbsp;1;
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2583 the default value for <code>j</code> is&nbsp;<code>i</code>.
556
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2584 These indices are corrected
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2585 following the same rules of function <a href="#String.sub"><code>String.sub</code></a>.
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2586
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2587
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2588
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2589
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 556
diff changeset
2590
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2591 <h4 heading><a name="String.upper" href="#String.upper"><code>String.upper (s)</code></a></h4>
556
d02f43598ba3 finish String documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 555
diff changeset
2592 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2593 Receives a string and returns a copy of this string with all
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2594 lowercase letters changed to uppercase.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2595 All other characters are left unchanged.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2596 The definition of what a lowercase letter is depends on the current locale.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2597
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2598
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2599
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2600
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2601
567
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2602 <h3 heading><a name="binary_lib">Binary Manipulation</a></h3>
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2603
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2604 <p>
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2605 Include this library by:
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2606
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2607 <pre>
693
ca169567ce07 module URIs must now include ".luan"
Franklin Schmidt <fschmidt@gmail.com>
parents: 685
diff changeset
2608 local Binary = require "luan:Binary.luan"
567
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2609 </pre>
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2610
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2611
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2612 <h4 heading><a name="Binary.binary" href="#Binary.binary"><code>Binary.binary (&middot;&middot;&middot;)</code></a></h4>
567
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2613
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2614 <p>
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2615 Receives zero or more bytes (as integers).
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2616 Returns a binary with length equal to the number of arguments,
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2617 in which each byte has the internal numerical code equal
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2618 to its corresponding argument.
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2619
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2620
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2621 <h4 heading><a name="Binary.byte" href="#Binary.byte"><code>Binary.byte (b [, i [, j]])</code></a></h4>
567
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2622
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2623 <p>
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2624 Returns the internal numerical codes of the bytes <code>b[i]</code>,
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2625 <code>b[i+1]</code>, ..., <code>b[j]</code>.
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2626 The default value for <code>i</code> is&nbsp;1;
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2627 the default value for <code>j</code> is&nbsp;<code>i</code>.
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2628 These indices are corrected
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2629 following the same rules of function <a href="#String.sub"><code>String.sub</code></a>.
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2630
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2631
1257
e38f5869e9df don't reset in send_redirect and other improvements
Franklin Schmidt <fschmidt@gmail.com>
parents: 1216
diff changeset
2632 <h4 heading><a name="Binary.to_string" href="#Binary.to_string"><code>Binary.to_string (b [,charset])</code></a></h4>
e38f5869e9df don't reset in send_redirect and other improvements
Franklin Schmidt <fschmidt@gmail.com>
parents: 1216
diff changeset
2633 <p>
e38f5869e9df don't reset in send_redirect and other improvements
Franklin Schmidt <fschmidt@gmail.com>
parents: 1216
diff changeset
2634 If <code>charset</code> is not nil then converts the binary <code>b</code> to a string using the Java <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#String(byte[],%20java.lang.String)">String constructor</a>, else makes each byte a char.
567
6c00b8a59240 document Binary
Franklin Schmidt <fschmidt@gmail.com>
parents: 566
diff changeset
2635
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2636
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2637
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2638
565
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2639 <h3 heading><a name="table_lib">Table Manipulation</a></h3>
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2640
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2641 <p>
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2642 Include this library by:
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2643
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2644 <pre>
693
ca169567ce07 module URIs must now include ".luan"
Franklin Schmidt <fschmidt@gmail.com>
parents: 685
diff changeset
2645 local Table = require "luan:Table.luan"
565
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2646 </pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2647
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2648 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2649 This library provides generic functions for table manipulation.
565
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2650 It provides all its functions inside the table <code>Table</code>.
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2651
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2652
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2653
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2654 <h4 heading><a name="Table.clear" href="#Table.clear"><code>Table.clear (tbl)</code></a></h4>
580
1e69d9c21461 add Table.clear();
Franklin Schmidt <fschmidt@gmail.com>
parents: 567
diff changeset
2655
1e69d9c21461 add Table.clear();
Franklin Schmidt <fschmidt@gmail.com>
parents: 567
diff changeset
2656 <p>
1e69d9c21461 add Table.clear();
Franklin Schmidt <fschmidt@gmail.com>
parents: 567
diff changeset
2657 Clears the table.
1e69d9c21461 add Table.clear();
Franklin Schmidt <fschmidt@gmail.com>
parents: 567
diff changeset
2658
1e69d9c21461 add Table.clear();
Franklin Schmidt <fschmidt@gmail.com>
parents: 567
diff changeset
2659
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2660 <h4 heading><a name="Table.concat" href="#Table.concat"><code>Table.concat (list [, sep [, i [, j]]])</code></a></h4>
565
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2661
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2662 <p>
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2663 Given a list,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2664 returns the string <code>list[i]..sep..list[i+1] &middot;&middot;&middot; sep..list[j]</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2665 The default value for <code>sep</code> is the empty string,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2666 the default for <code>i</code> is 1,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2667 and the default for <code>j</code> is <code>#list</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2668 If <code>i</code> is greater than <code>j</code>, returns the empty string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2669
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2670
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2671 <h4 heading><a name="Table.copy" href="#Table.copy"><code>Table.copy (tbl [, i [, j]])</code></a></h4>
565
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2672
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2673 <p>
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2674 If <code>i</code> is <code>nil</code>, returns a shallow copy of <code>tbl</code>.
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2675 Otherwise returns a new table which is a list of the elements <code>tbl[i] &middot;&middot;&middot; tbl[j]</code>.
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2676 By default, <code>j</code> is <code>#tbl</code>.
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2677
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2678
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2679
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2680 <h4 heading><a name="Table.insert" href="#Table.insert"><code>Table.insert (list, pos, value)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2681
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2682 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2683 Inserts element <code>value</code> at position <code>pos</code> in <code>list</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2684 shifting up the elements
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2685 <code>list[pos], list[pos+1], &middot;&middot;&middot;, list[#list]</code>.
565
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2686
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2687
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2688
1100
ad6b3b9fef40 add Table.is_empty() and Table.size()
Franklin Schmidt <fschmidt@gmail.com>
parents: 1092
diff changeset
2689 <h4 heading><a name="Table.is_empty" href="#Table.is_empty"><code>Table.is_empty (tbl)</code></a></h4>
ad6b3b9fef40 add Table.is_empty() and Table.size()
Franklin Schmidt <fschmidt@gmail.com>
parents: 1092
diff changeset
2690
ad6b3b9fef40 add Table.is_empty() and Table.size()
Franklin Schmidt <fschmidt@gmail.com>
parents: 1092
diff changeset
2691
ad6b3b9fef40 add Table.is_empty() and Table.size()
Franklin Schmidt <fschmidt@gmail.com>
parents: 1092
diff changeset
2692
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2693 <h4 heading><a name="Table.pack" href="#Table.pack"><code>Table.pack (&middot;&middot;&middot;)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2694
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2695 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2696 Returns a new table with all parameters stored into keys 1, 2, etc.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2697 and with a field "<code>n</code>" with the total number of parameters.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2698 Note that the resulting table may not be a sequence.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2699
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2700
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2701
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2702
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2703 <h4 heading><a name="Table.remove" href="#Table.remove"><code>Table.remove (list, pos)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2704
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2705
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2706 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2707 Removes from <code>list</code> the element at position <code>pos</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2708 returning the value of the removed element.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2709 When <code>pos</code> is an integer between 1 and <code>#list</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2710 it shifts down the elements
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2711 <code>list[pos+1], list[pos+2], &middot;&middot;&middot;, list[#list]</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2712 and erases element <code>list[#list]</code>;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2713 The index <code>pos</code> can also be 0 when <code>#list</code> is 0,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2714 or <code>#list + 1</code>;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2715 in those cases, the function erases the element <code>list[pos]</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2716
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2717
565
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2718
1100
ad6b3b9fef40 add Table.is_empty() and Table.size()
Franklin Schmidt <fschmidt@gmail.com>
parents: 1092
diff changeset
2719 <h4 heading><a name="Table.size" href="#Table.size"><code>Table.size (tbl)</code></a></h4>
ad6b3b9fef40 add Table.is_empty() and Table.size()
Franklin Schmidt <fschmidt@gmail.com>
parents: 1092
diff changeset
2720
ad6b3b9fef40 add Table.is_empty() and Table.size()
Franklin Schmidt <fschmidt@gmail.com>
parents: 1092
diff changeset
2721
565
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2722
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2723 <h4 heading><a name="Table.sort" href="#Table.sort"><code>Table.sort (list [, comp])</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2724
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2725 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2726 Sorts list elements in a given order, <em>in-place</em>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2727 from <code>list[1]</code> to <code>list[#list]</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2728 If <code>comp</code> is given,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2729 then it must be a function that receives two list elements
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2730 and returns true when the first element must come
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2731 before the second in the final order
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2732 (so that <code>not comp(list[i+1],list[i])</code> will be true after the sort).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2733 If <code>comp</code> is not given,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2734 then the standard Lua operator <code>&lt;</code> is used instead.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2735
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2736 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2737 The sort algorithm is not stable;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2738 that is, elements considered equal by the given order
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2739 may have their relative positions changed by the sort.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2740
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2741
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2742
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2743 <h4 heading><a name="Table.unpack" href="#Table.unpack"><code>Table.unpack (list [, i [, j]])</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2744
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2745 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2746 Returns the elements from the given list.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2747 This function is equivalent to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2748
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2749 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2750 return list[i], list[i+1], &middot;&middot;&middot;, list[j]
565
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2751 </pre>
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2752
22bfd8a2eaee do Table documentation;
Franklin Schmidt <fschmidt@gmail.com>
parents: 562
diff changeset
2753 <p>
1277
5ba660381bd5 fix Io.print()
Franklin Schmidt <fschmidt@gmail.com>
parents: 1276
diff changeset
2754 By default, <code>i</code> is 1 and <code>j</code> is <code>list.n or #list</code>.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2755
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2756
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2757
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2758
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2759 <h3 heading><a name="number_lib">Number Manipulation</a></h3>
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2760
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2761 <p>
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2762 Include this library by:
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2763
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2764 <pre>
693
ca169567ce07 module URIs must now include ".luan"
Franklin Schmidt <fschmidt@gmail.com>
parents: 685
diff changeset
2765 local Number = require "luan:Number.luan"
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2766 </pre>
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2767
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2768
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2769 <h4 heading><a name="Number.double" href="#Number.double"><code>Number.double (x)</code></a></h4>
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2770 <p>
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2771 Returns <code>x</code> as a double.
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2772
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2773
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2774 <h4 heading><a name="Number.integer" href="#Number.integer"><code>Number.integer (x)</code></a></h4>
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2775 <p>
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2776 If the value <code>x</code> is convertible to an integer,
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2777 returns that integer.
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2778 Otherwise throws an error.
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2779
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2780
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2781 <h4 heading><a name="Number.long" href="#Number.long"><code>Number.long (x)</code></a></h4>
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2782 <p>
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2783 If the value <code>x</code> is convertible to an long,
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2784 returns that long.
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2785 Otherwise throws an error.
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2786
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2787
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2788 <h4 heading><a name="Number.long_to_string" href="#Number.long_to_string"><code>Number.long_to_string (i, radix)</code></a></h4>
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2789 <p>
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2790 Converts long value <code>i</code> to a string by calling <code><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Long.html#toString(long,%20int)">Long.toString</a></code>.
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2791
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2792
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2793 <h4 heading><a name="Number.type" href="#Number.type"><code>Number.type (x)</code></a></h4>
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2794 <p>
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2795 Returns a string for the numeric type of <code>x</code>. Possible return values include "<code>integer</code>", "<code>long</code>", "<code>double</code>", and "<code>float</code>".
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2796
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2797
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2798
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2799
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2800 <h3 heading><a name="math_lib">Mathematical Functions</a></h3>
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2801
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2802 <p>
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2803 Include this library by:
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2804
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2805 <pre>
693
ca169567ce07 module URIs must now include ".luan"
Franklin Schmidt <fschmidt@gmail.com>
parents: 685
diff changeset
2806 local Math = require "luan:Math.luan"
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2807 </pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2808
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2809 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2810 This library provides basic mathematical functions.
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2811 It provides all its functions and constants inside the table <code>Math</code>.
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2812
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2813
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2814 <h4 heading><a name="Math.abs" href="#Math.abs"><code>Math.abs (x)</code></a></h4>
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2815
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2816 <p>
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2817 Returns the absolute value of <code>x</code>.
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2818
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2819
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2820
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2821 <h4 heading><a name="Math.acos" href="#Math.acos"><code>Math.acos (x)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2822
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2823 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2824 Returns the arc cosine of <code>x</code> (in radians).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2825
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2826
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2827
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2828
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2829 <h4 heading><a name="Math.asin" href="#Math.asin"><code>Math.asin (x)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2830
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2831 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2832 Returns the arc sine of <code>x</code> (in radians).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2833
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2834
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2835
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2836
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2837 <h4 heading><a name="Math.atan" href="#Math.atan"><code>Math.atan (y, x)</code></a></h4>
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2838
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2839 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2840 Returns the arc tangent of <code>y/x</code> (in radians),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2841 but uses the signs of both parameters to find the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2842 quadrant of the result.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2843 (It also handles correctly the case of <code>x</code> being zero.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2844
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2845
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2846
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2847
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2848 <h4 heading><a name="Math.ceil" href="#Math.ceil"><code>Math.ceil (x)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2849
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2850 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2851 Returns the smallest integral value larger than or equal to <code>x</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2852
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2853
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2854
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2855
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2856 <h4 heading><a name="Math.cos" href="#Math.cos"><code>Math.cos (x)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2857
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2858 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2859 Returns the cosine of <code>x</code> (assumed to be in radians).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2860
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2861
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2862
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2863
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2864 <h4 heading><a name="Math.deg" href="#Math.deg"><code>Math.deg (x)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2865
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2866 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2867 Converts the angle <code>x</code> from radians to degrees.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2868
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2869
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2870
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2871
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2872 <h4 heading><a name="Math.exp" href="#Math.exp"><code>Math.exp (x)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2873
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2874 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2875 Returns the value <em>e<sup>x</sup></em>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2876 (where <code>e</code> is the base of natural logarithms).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2877
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2878
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2879
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2880
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2881 <h4 heading><a name="Math.floor" href="#Math.floor"><code>Math.floor (x)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2882
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2883 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2884 Returns the largest integral value smaller than or equal to <code>x</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2885
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2886
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2887
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2888
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2889 <h4 heading><a name="Math.fmod" href="#Math.fmod"><code>Math.fmod (x, y)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2890
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2891 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2892 Returns the remainder of the division of <code>x</code> by <code>y</code>
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2893 that rounds the quotient towards zero.
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2894
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2895
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2896
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2897
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2898 <h4 heading><a name="Math.huge" href="#Math.huge"><code>Math.huge</code></a></h4>
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2899
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2900 <p>
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2901 A value larger than any other numerical value.
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2902
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2903
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2904
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2905
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2906 <h4 heading><a name="Math.log" href="#Math.log"><code>Math.log (x [, base])</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2907
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2908 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2909 Returns the logarithm of <code>x</code> in the given base.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2910 The default for <code>base</code> is <em>e</em>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2911 (so that the function returns the natural logarithm of <code>x</code>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2912
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2913
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2914
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2915
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2916 <h4 heading><a name="Math.max" href="#Math.max"><code>Math.max (x, &middot;&middot;&middot;)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2917
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2918 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2919 Returns the argument with the maximum value,
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2920 according to the Lua operator <code>&lt;</code>.
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2921
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2922
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2923
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2924
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2925 <h4 heading><a name="Math.max_integer" href="#Math.max_integer"><code>Math.max_integer</code></a></h4>
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2926 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2927 An integer with the maximum value for an integer.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2928
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2929
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2930
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2931
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2932 <h4 heading><a name="Math.min" href="#Math.min"><code>Math.min (x, &middot;&middot;&middot;)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2933
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2934 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2935 Returns the argument with the minimum value,
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2936 according to the Lua operator <code>&lt;</code>.
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2937
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2938
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2939
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2940
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2941 <h4 heading><a name="Math.min_integer" href="#Math.min_integer"><code>Math.min_integer</code></a></h4>
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2942 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2943 An integer with the minimum value for an integer.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2944
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2945
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2946
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2947
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2948 <h4 heading><a name="Math.modf" href="#Math.modf"><code>Math.modf (x)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2949
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2950 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2951 Returns the integral part of <code>x</code> and the fractional part of <code>x</code>.
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2952
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2953
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2954
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2955
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2956 <h4 heading><a name="Math.pi" href="#Math.pi"><code>Math.pi</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2957
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2958 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2959 The value of <em>&pi;</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2960
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2961
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2962
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2963
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2964 <h4 heading><a name="Math.rad" href="#Math.rad"><code>Math.rad (x)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2965
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2966 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2967 Converts the angle <code>x</code> from degrees to radians.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2968
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2969
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2970
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2971
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2972 <h4 heading><a name="Math.random" href="#Math.random"><code>Math.random ([m [, n])</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2973
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2974
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2975 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2976 When called without arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2977 returns a pseudo-random float with uniform distribution
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2978 in the range <em>[0,1)</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2979 When called with two integers <code>m</code> and <code>n</code>,
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2980 <code>Math.random</code> returns a pseudo-random integer
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2981 with uniform distribution in the range <em>[m, n]</em>.
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2982 (The value <em>m-n</em> cannot be negative and must fit in a Luan integer.)
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2983 The call <code>Math.random(n)</code> is equivalent to <code>Math.random(1,n)</code>.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2984
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2985
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2986 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2987 This function is an interface to the underling
566
90b93790c544 Number and Math documentation and minor changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 565
diff changeset
2988 pseudo-random generator function provided by Java.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2989 No guarantees can be given for its statistical properties.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2990
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2991
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2992
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2993
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
2994 <h4 heading><a name="Math.sin" href="#Math.sin"><code>Math.sin (x)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2995
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2996 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2997 Returns the sine of <code>x</code> (assumed to be in radians).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2998
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2999
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3000
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3001
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
3002 <h4 heading><a name="Math.sqrt" href="#Math.sqrt"><code>Math.sqrt (x)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3003
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3004 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3005 Returns the square root of <code>x</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3006 (You can also use the expression <code>x^0.5</code> to compute this value.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3007
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3008
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3009
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3010
642
c4216a583de4 add links to functions in manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 629
diff changeset
3011 <h4 heading><a name="Math.tan" href="#Math.tan"><code>Math.tan (x)</code></a></h4>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3012
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3013 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3014 Returns the tangent of <code>x</code> (assumed to be in radians).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3015
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3016
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3017
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3018
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3019
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3020
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3021
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3022
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3023 <h2>6.8 &ndash; <a name="6.8">Input and Output Facilities</a></h2>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3024
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3025 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3026 The I/O library provides two different styles for file manipulation.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3027 The first one uses implicit file handles;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3028 that is, there are operations to set a default input file and a
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3029 default output file,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3030 and all input/output operations are over these default files.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3031 The second style uses explicit file handles.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3032
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3033
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3034 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3035 When using implicit file handles,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3036 all operations are supplied by table <a name="pdf-io"><code>io</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3037 When using explicit file handles,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3038 the operation <a href="#pdf-io.open"><code>io.open</code></a> returns a file handle
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3039 and then all operations are supplied as methods of the file handle.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3040
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3041
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3042 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3043 The table <code>io</code> also provides
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3044 three predefined file handles with their usual meanings from C:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3045 <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>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3046 The I/O library never closes these files.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3047
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3048
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3049 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3050 Unless otherwise stated,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3051 all I/O functions return <b>nil</b> on failure
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3052 (plus an error message as a second result and
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3053 a system-dependent error code as a third result)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3054 and some value different from <b>nil</b> on success.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3055 On non-POSIX systems,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3056 the computation of the error message and error code
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3057 in case of errors
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3058 may be not thread safe,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3059 because they rely on the global C variable <code>errno</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3060
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3061
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3062 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3063 <hr><h3><a name="pdf-io.close"><code>io.close ([file])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3064
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3065
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3066 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3067 Equivalent to <code>file:close()</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3068 Without a <code>file</code>, closes the default output file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3069
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3070
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3071
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3072
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3073 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3074 <hr><h3><a name="pdf-io.flush"><code>io.flush ()</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3075
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3076
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3077 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3078 Equivalent to <code>io.output():flush()</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3079
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3080
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3081
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3082
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3083 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3084 <hr><h3><a name="pdf-io.input"><code>io.input ([file])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3085
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3086
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3087 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3088 When called with a file name, it opens the named file (in text mode),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3089 and sets its handle as the default input file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3090 When called with a file handle,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3091 it simply sets this file handle as the default input file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3092 When called without parameters,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3093 it returns the current default input file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3094
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3095
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3096 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3097 In case of errors this function raises the error,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3098 instead of returning an error code.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3099
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3100
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3101
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3102
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3103 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3104 <hr><h3><a name="pdf-io.lines"><code>io.lines ([filename &middot;&middot;&middot;])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3105
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3106
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3107 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3108 Opens the given file name in read mode
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3109 and returns an iterator function that
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3110 works like <code>file:lines(&middot;&middot;&middot;)</code> over the opened file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3111 When the iterator function detects the end of file,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3112 it returns no values (to finish the loop) and automatically closes the file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3113
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3114
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3115 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3116 The call <code>io.lines()</code> (with no file name) is equivalent
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3117 to <code>io.input():lines("*l")</code>;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3118 that is, it iterates over the lines of the default input file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3119 In this case it does not close the file when the loop ends.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3120
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3121
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3122 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3123 In case of errors this function raises the error,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3124 instead of returning an error code.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3125
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3126
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3127
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3128
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3129 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3130 <hr><h3><a name="pdf-io.open"><code>io.open (filename [, mode])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3131
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3132
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3133 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3134 This function opens a file,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3135 in the mode specified in the string <code>mode</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3136 It returns a new file handle,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3137 or, in case of errors, <b>nil</b> plus an error message.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3138
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3139
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3140 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3141 The <code>mode</code> string can be any of the following:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3142
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3143 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3144 <li><b>"<code>r</code>": </b> read mode (the default);</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3145 <li><b>"<code>w</code>": </b> write mode;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3146 <li><b>"<code>a</code>": </b> append mode;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3147 <li><b>"<code>r+</code>": </b> update mode, all previous data is preserved;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3148 <li><b>"<code>w+</code>": </b> update mode, all previous data is erased;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3149 <li><b>"<code>a+</code>": </b> append update mode, previous data is preserved,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3150 writing is only allowed at the end of file.</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3151 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3152 The <code>mode</code> string can also have a '<code>b</code>' at the end,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3153 which is needed in some systems to open the file in binary mode.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3154
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3155
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3156
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3157
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3158 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3159 <hr><h3><a name="pdf-io.output"><code>io.output ([file])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3160
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3161
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3162 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3163 Similar to <a href="#pdf-io.input"><code>io.input</code></a>, but operates over the default output file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3164
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3165
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3166
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3167
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3168 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3169 <hr><h3><a name="pdf-io.popen"><code>io.popen (prog [, mode])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3170
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3171
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3172 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3173 This function is system dependent and is not available
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3174 on all platforms.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3175
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3176
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3177 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3178 Starts program <code>prog</code> in a separated process and returns
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3179 a file handle that you can use to read data from this program
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3180 (if <code>mode</code> is <code>"r"</code>, the default)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3181 or to write data to this program
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3182 (if <code>mode</code> is <code>"w"</code>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3183
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3184
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3185
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3186
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3187 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3188 <hr><h3><a name="pdf-io.read"><code>io.read (&middot;&middot;&middot;)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3189
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3190
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3191 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3192 Equivalent to <code>io.input():read(&middot;&middot;&middot;)</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3193
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3194
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3195
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3196
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3197 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3198 <hr><h3><a name="pdf-io.tmpfile"><code>io.tmpfile ()</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3199
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3200
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3201 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3202 Returns a handle for a temporary file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3203 This file is opened in update mode
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3204 and it is automatically removed when the program ends.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3205
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3206
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3207
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3208
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3209 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3210 <hr><h3><a name="pdf-io.type"><code>io.type (obj)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3211
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3212
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3213 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3214 Checks whether <code>obj</code> is a valid file handle.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3215 Returns the string <code>"file"</code> if <code>obj</code> is an open file handle,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3216 <code>"closed file"</code> if <code>obj</code> is a closed file handle,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3217 or <b>nil</b> if <code>obj</code> is not a file handle.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3218
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3219
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3220
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3221
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3222 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3223 <hr><h3><a name="pdf-io.write"><code>io.write (&middot;&middot;&middot;)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3224
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3225
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3226 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3227 Equivalent to <code>io.output():write(&middot;&middot;&middot;)</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3228
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3229
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3230
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3231
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3232 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3233 <hr><h3><a name="pdf-file:close"><code>file:close ()</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3234
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3235
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3236 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3237 Closes <code>file</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3238 Note that files are automatically closed when
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3239 their handles are garbage collected,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3240 but that takes an unpredictable amount of time to happen.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3241
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3242
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3243 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3244 When closing a file handle created with <a href="#pdf-io.popen"><code>io.popen</code></a>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3245 <a href="#pdf-file:close"><code>file:close</code></a> returns the same values
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3246 returned by <a href="#pdf-os.execute"><code>os.execute</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3247
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3248
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3249
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3250
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3251 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3252 <hr><h3><a name="pdf-file:flush"><code>file:flush ()</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3253
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3254
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3255 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3256 Saves any written data to <code>file</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3257
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3258
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3259
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3260
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3261 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3262 <hr><h3><a name="pdf-file:lines"><code>file:lines (&middot;&middot;&middot;)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3263
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3264
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3265 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3266 Returns an iterator function that,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3267 each time it is called,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3268 reads the file according to the given formats.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3269 When no format is given,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3270 uses "<code>l</code>" as a default.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3271 As an example, the construction
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3272
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3273 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3274 for c in file:lines(1) do <em>body</em> end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3275 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3276 will iterate over all characters of the file,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3277 starting at the current position.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3278 Unlike <a href="#pdf-io.lines"><code>io.lines</code></a>, this function does not close the file
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3279 when the loop ends.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3280
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3281
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3282 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3283 In case of errors this function raises the error,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3284 instead of returning an error code.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3285
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3286
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3287
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3288
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3289 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3290 <hr><h3><a name="pdf-file:read"><code>file:read (&middot;&middot;&middot;)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3291
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3292
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3293 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3294 Reads the file <code>file</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3295 according to the given formats, which specify what to read.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3296 For each format,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3297 the function returns a string or a number with the characters read,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3298 or <b>nil</b> if it cannot read data with the specified format.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3299 (In this latter case,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3300 the function does not read subsequent formats.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3301 When called without formats,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3302 it uses a default format that reads the next line
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3303 (see below).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3304
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3305
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3306 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3307 The available formats are
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3308
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3309 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3310
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3311 <li><b>"<code>n</code>": </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3312 reads a numeral and returns it as a float or an integer,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3313 following the lexical conventions of Lua.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3314 (The numeral may have leading spaces and a sign.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3315 This format always reads the longest input sequence that
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3316 is a valid prefix for a number;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3317 if that prefix does not form a valid number
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3318 (e.g., an empty string, "<code>0x</code>", or "<code>3.4e-</code>"),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3319 it is discarded and the function returns <b>nil</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3320 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3321
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3322 <li><b>"<code>i</code>": </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3323 reads an integral number and returns it as an integer.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3324 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3325
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3326 <li><b>"<code>a</code>": </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3327 reads the whole file, starting at the current position.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3328 On end of file, it returns the empty string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3329 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3330
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3331 <li><b>"<code>l</code>": </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3332 reads the next line skipping the end of line,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3333 returning <b>nil</b> on end of file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3334 This is the default format.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3335 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3336
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3337 <li><b>"<code>L</code>": </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3338 reads the next line keeping the end-of-line character (if present),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3339 returning <b>nil</b> on end of file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3340 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3341
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3342 <li><b><em>number</em>: </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3343 reads a string with up to this number of bytes,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3344 returning <b>nil</b> on end of file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3345 If <code>number</code> is zero,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3346 it reads nothing and returns an empty string,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3347 or <b>nil</b> on end of file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3348 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3349
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3350 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3351 The formats "<code>l</code>" and "<code>L</code>" should be used only for text files.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3352
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3353
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3354
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3355
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3356 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3357 <hr><h3><a name="pdf-file:seek"><code>file:seek ([whence [, offset]])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3358
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3359
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3360 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3361 Sets and gets the file position,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3362 measured from the beginning of the file,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3363 to the position given by <code>offset</code> plus a base
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3364 specified by the string <code>whence</code>, as follows:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3365
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3366 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3367 <li><b>"<code>set</code>": </b> base is position 0 (beginning of the file);</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3368 <li><b>"<code>cur</code>": </b> base is current position;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3369 <li><b>"<code>end</code>": </b> base is end of file;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3370 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3371 In case of success, <code>seek</code> returns the final file position,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3372 measured in bytes from the beginning of the file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3373 If <code>seek</code> fails, it returns <b>nil</b>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3374 plus a string describing the error.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3375
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3376
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3377 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3378 The default value for <code>whence</code> is <code>"cur"</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3379 and for <code>offset</code> is 0.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3380 Therefore, the call <code>file:seek()</code> returns the current
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3381 file position, without changing it;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3382 the call <code>file:seek("set")</code> sets the position to the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3383 beginning of the file (and returns 0);
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3384 and the call <code>file:seek("end")</code> sets the position to the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3385 end of the file, and returns its size.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3386
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3387
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3388
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3389
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3390 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3391 <hr><h3><a name="pdf-file:setvbuf"><code>file:setvbuf (mode [, size])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3392
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3393
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3394 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3395 Sets the buffering mode for an output file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3396 There are three available modes:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3397
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3398 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3399
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3400 <li><b>"<code>no</code>": </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3401 no buffering; the result of any output operation appears immediately.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3402 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3403
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3404 <li><b>"<code>full</code>": </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3405 full buffering; output operation is performed only
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3406 when the buffer is full or when
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3407 you explicitly <code>flush</code> the file (see <a href="#pdf-io.flush"><code>io.flush</code></a>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3408 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3409
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3410 <li><b>"<code>line</code>": </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3411 line buffering; output is buffered until a newline is output
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3412 or there is any input from some special files
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3413 (such as a terminal device).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3414 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3415
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3416 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3417 For the last two cases, <code>size</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3418 specifies the size of the buffer, in bytes.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3419 The default is an appropriate size.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3420
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3421
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3422
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3423
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3424 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3425 <hr><h3><a name="pdf-file:write"><code>file:write (&middot;&middot;&middot;)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3426
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3427
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3428 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3429 Writes the value of each of its arguments to <code>file</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3430 The arguments must be strings or numbers.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3431
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3432
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3433 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3434 In case of success, this function returns <code>file</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3435 Otherwise it returns <b>nil</b> plus a string describing the error.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3436
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3437
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3438
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3439
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3440
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3441
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3442
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3443 <h2>6.9 &ndash; <a name="6.9">Operating System Facilities</a></h2>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3444
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3445 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3446 This library is implemented through table <a name="pdf-os"><code>os</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3447
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3448
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3449 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3450 <hr><h3><a name="pdf-os.clock"><code>os.clock ()</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3451
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3452
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3453 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3454 Returns an approximation of the amount in seconds of CPU time
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3455 used by the program.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3456
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3457
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3458
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3459
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3460 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3461 <hr><h3><a name="pdf-os.date"><code>os.date ([format [, time]])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3462
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3463
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3464 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3465 Returns a string or a table containing date and time,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3466 formatted according to the given string <code>format</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3467
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3468
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3469 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3470 If the <code>time</code> argument is present,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3471 this is the time to be formatted
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3472 (see the <a href="#pdf-os.time"><code>os.time</code></a> function for a description of this value).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3473 Otherwise, <code>date</code> formats the current time.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3474
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3475
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3476 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3477 If <code>format</code> starts with '<code>!</code>',
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3478 then the date is formatted in Coordinated Universal Time.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3479 After this optional character,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3480 if <code>format</code> is the string "<code>*t</code>",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3481 then <code>date</code> returns a table with the following fields:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3482 <code>year</code> (four digits), <code>month</code> (1&ndash;12), <code>day</code> (1&ndash;31),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3483 <code>hour</code> (0&ndash;23), <code>min</code> (0&ndash;59), <code>sec</code> (0&ndash;61),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3484 <code>wday</code> (weekday, Sunday is&nbsp;1),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3485 <code>yday</code> (day of the year),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3486 and <code>isdst</code> (daylight saving flag, a boolean).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3487 This last field may be absent
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3488 if the information is not available.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3489
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3490
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3491 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3492 If <code>format</code> is not "<code>*t</code>",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3493 then <code>date</code> returns the date as a string,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3494 formatted according to the same rules as the ISO&nbsp;C function <code>strftime</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3495
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3496
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3497 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3498 When called without arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3499 <code>date</code> returns a reasonable date and time representation that depends on
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3500 the host system and on the current locale
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3501 (that is, <code>os.date()</code> is equivalent to <code>os.date("%c")</code>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3502
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3503
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3504 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3505 On non-POSIX systems,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3506 this function may be not thread safe
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3507 because of its reliance on C&nbsp;function <code>gmtime</code> and C&nbsp;function <code>localtime</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3508
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3509
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3510
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3511
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3512 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3513 <hr><h3><a name="pdf-os.difftime"><code>os.difftime (t2, t1)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3514
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3515
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3516 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3517 Returns the difference, in seconds,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3518 from time <code>t1</code> to time <code>t2</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3519 (where the times are values returned by <a href="#pdf-os.time"><code>os.time</code></a>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3520 In POSIX, Windows, and some other systems,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3521 this value is exactly <code>t2</code><em>-</em><code>t1</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3522
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3523
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3524
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3525
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3526 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3527 <hr><h3><a name="pdf-os.execute"><code>os.execute ([command])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3528
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3529
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3530 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3531 This function is equivalent to the ISO&nbsp;C function <code>system</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3532 It passes <code>command</code> to be executed by an operating system shell.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3533 Its first result is <b>true</b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3534 if the command terminated successfully,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3535 or <b>nil</b> otherwise.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3536 After this first result
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3537 the function returns a string plus a number,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3538 as follows:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3539
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3540 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3541
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3542 <li><b>"<code>exit</code>": </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3543 the command terminated normally;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3544 the following number is the exit status of the command.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3545 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3546
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3547 <li><b>"<code>signal</code>": </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3548 the command was terminated by a signal;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3549 the following number is the signal that terminated the command.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3550 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3551
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3552 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3553
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3554 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3555 When called without a <code>command</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3556 <code>os.execute</code> returns a boolean that is true if a shell is available.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3557
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3558
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3559
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3560
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3561 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3562 <hr><h3><a name="pdf-os.exit"><code>os.exit ([code [, close]])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3563
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3564
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3565 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3566 Calls the ISO&nbsp;C function <code>exit</code> to terminate the host program.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3567 If <code>code</code> is <b>true</b>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3568 the returned status is <code>EXIT_SUCCESS</code>;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3569 if <code>code</code> is <b>false</b>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3570 the returned status is <code>EXIT_FAILURE</code>;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3571 if <code>code</code> is a number,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3572 the returned status is this number.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3573 The default value for <code>code</code> is <b>true</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3574
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3575
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3576 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3577 If the optional second argument <code>close</code> is true,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3578 closes the Lua state before exiting.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3579
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3580
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3581
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3582
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3583 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3584 <hr><h3><a name="pdf-os.getenv"><code>os.getenv (varname)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3585
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3586
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3587 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3588 Returns the value of the process environment variable <code>varname</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3589 or <b>nil</b> if the variable is not defined.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3590
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3591
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3592
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3593
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3594 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3595 <hr><h3><a name="pdf-os.remove"><code>os.remove (filename)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3596
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3597
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3598 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3599 Deletes the file (or empty directory, on POSIX systems)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3600 with the given name.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3601 If this function fails, it returns <b>nil</b>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3602 plus a string describing the error and the error code.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3603
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3604
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3605
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3606
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3607 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3608 <hr><h3><a name="pdf-os.rename"><code>os.rename (oldname, newname)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3609
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3610
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3611 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3612 Renames file or directory named <code>oldname</code> to <code>newname</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3613 If this function fails, it returns <b>nil</b>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3614 plus a string describing the error and the error code.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3615
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3616
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3617
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3618
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3619 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3620 <hr><h3><a name="pdf-os.setlocale"><code>os.setlocale (locale [, category])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3621
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3622
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3623 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3624 Sets the current locale of the program.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3625 <code>locale</code> is a system-dependent string specifying a locale;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3626 <code>category</code> is an optional string describing which category to change:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3627 <code>"all"</code>, <code>"collate"</code>, <code>"ctype"</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3628 <code>"monetary"</code>, <code>"numeric"</code>, or <code>"time"</code>;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3629 the default category is <code>"all"</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3630 The function returns the name of the new locale,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3631 or <b>nil</b> if the request cannot be honored.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3632
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3633
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3634 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3635 If <code>locale</code> is the empty string,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3636 the current locale is set to an implementation-defined native locale.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3637 If <code>locale</code> is the string "<code>C</code>",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3638 the current locale is set to the standard C locale.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3639
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3640
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3641 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3642 When called with <b>nil</b> as the first argument,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3643 this function only returns the name of the current locale
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3644 for the given category.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3645
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3646
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3647 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3648 This function may be not thread safe
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3649 because of its reliance on C&nbsp;function <code>setlocale</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3650
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3651
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3652
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3653
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3654 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3655 <hr><h3><a name="pdf-os.time"><code>os.time ([table])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3656
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3657
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3658 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3659 Returns the current time when called without arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3660 or a time representing the date and time specified by the given table.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3661 This table must have fields <code>year</code>, <code>month</code>, and <code>day</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3662 and may have fields
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3663 <code>hour</code> (default is 12),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3664 <code>min</code> (default is 0),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3665 <code>sec</code> (default is 0),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3666 and <code>isdst</code> (default is <b>nil</b>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3667 For a description of these fields, see the <a href="#pdf-os.date"><code>os.date</code></a> function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3668
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3669
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3670 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3671 The returned value is a number, whose meaning depends on your system.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3672 In POSIX, Windows, and some other systems,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3673 this number counts the number
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3674 of seconds since some given start time (the "epoch").
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3675 In other systems, the meaning is not specified,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3676 and the number returned by <code>time</code> can be used only as an argument to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3677 <a href="#pdf-os.date"><code>os.date</code></a> and <a href="#pdf-os.difftime"><code>os.difftime</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3678
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3679
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3680
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3681
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3682 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3683 <hr><h3><a name="pdf-os.tmpname"><code>os.tmpname ()</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3684
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3685
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3686 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3687 Returns a string with a file name that can
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3688 be used for a temporary file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3689 The file must be explicitly opened before its use
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3690 and explicitly removed when no longer needed.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3691
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3692
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3693 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3694 On POSIX systems,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3695 this function also creates a file with that name,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3696 to avoid security risks.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3697 (Someone else might create the file with wrong permissions
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3698 in the time between getting the name and creating the file.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3699 You still have to open the file to use it
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3700 and to remove it (even if you do not use it).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3701
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3702
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3703 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3704 When possible,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3705 you may prefer to use <a href="#pdf-io.tmpfile"><code>io.tmpfile</code></a>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3706 which automatically removes the file when the program ends.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3707
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3708
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3709
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3710
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3711
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3712
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3713
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3714 <h2>6.10 &ndash; <a name="6.10">The Debug Library</a></h2>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3715
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3716 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3717 This library provides
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3718 the functionality of the debug interface (<a href="#4.9">&sect;4.9</a>) to Lua programs.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3719 You should exert care when using this library.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3720 Several of its functions
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3721 violate basic assumptions about Lua code
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3722 (e.g., that variables local to a function
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3723 cannot be accessed from outside;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3724 that userdata metatables cannot be changed by Lua code;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3725 that Lua programs do not crash)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3726 and therefore can compromise otherwise secure code.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3727 Moreover, some functions in this library may be slow.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3728
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3729
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3730 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3731 All functions in this library are provided
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3732 inside the <a name="pdf-debug"><code>debug</code></a> table.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3733 All functions that operate over a thread
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3734 have an optional first argument which is the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3735 thread to operate over.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3736 The default is always the current thread.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3737
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3738
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3739 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3740 <hr><h3><a name="pdf-debug.debug"><code>debug.debug ()</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3741
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3742
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3743 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3744 Enters an interactive mode with the user,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3745 running each string that the user enters.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3746 Using simple commands and other debug facilities,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3747 the user can inspect global and local variables,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3748 change their values, evaluate expressions, and so on.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3749 A line containing only the word <code>cont</code> finishes this function,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3750 so that the caller continues its execution.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3751
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3752
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3753 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3754 Note that commands for <code>debug.debug</code> are not lexically nested
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3755 within any function and so have no direct access to local variables.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3756
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3757
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3758
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3759
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3760 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3761 <hr><h3><a name="pdf-debug.gethook"><code>debug.gethook ([thread])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3762
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3763
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3764 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3765 Returns the current hook settings of the thread, as three values:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3766 the current hook function, the current hook mask,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3767 and the current hook count
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3768 (as set by the <a href="#pdf-debug.sethook"><code>debug.sethook</code></a> function).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3769
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3770
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3771
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3772
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3773 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3774 <hr><h3><a name="pdf-debug.getinfo"><code>debug.getinfo ([thread,] f [, what])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3775
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3776
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3777 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3778 Returns a table with information about a function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3779 You can give the function directly
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3780 or you can give a number as the value of <code>f</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3781 which means the function running at level <code>f</code> of the call stack
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3782 of the given thread:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3783 level&nbsp;0 is the current function (<code>getinfo</code> itself);
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3784 level&nbsp;1 is the function that called <code>getinfo</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3785 (except for tail calls, which do not count on the stack);
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3786 and so on.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3787 If <code>f</code> is a number larger than the number of active functions,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3788 then <code>getinfo</code> returns <b>nil</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3789
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3790
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3791 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3792 The returned table can contain all the fields returned by <a href="#lua_getinfo"><code>lua_getinfo</code></a>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3793 with the string <code>what</code> describing which fields to fill in.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3794 The default for <code>what</code> is to get all information available,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3795 except the table of valid lines.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3796 If present,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3797 the option '<code>f</code>'
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3798 adds a field named <code>func</code> with the function itself.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3799 If present,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3800 the option '<code>L</code>'
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3801 adds a field named <code>activelines</code> with the table of
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3802 valid lines.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3803
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3804
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3805 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3806 For instance, the expression <code>debug.getinfo(1,"n").name</code> returns
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3807 a table with a name for the current function,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3808 if a reasonable name can be found,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3809 and the expression <code>debug.getinfo(print)</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3810 returns a table with all available information
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3811 about the <a href="#pdf-print"><code>print</code></a> function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3812
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3813
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3814
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3815
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3816 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3817 <hr><h3><a name="pdf-debug.getlocal"><code>debug.getlocal ([thread,] f, local)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3818
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3819
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3820 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3821 This function returns the name and the value of the local variable
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3822 with index <code>local</code> of the function at level <code>f</code> of the stack.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3823 This function accesses not only explicit local variables,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3824 but also parameters, temporaries, etc.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3825
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3826
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3827 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3828 The first parameter or local variable has index&nbsp;1, and so on,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3829 following the order that they are declared in the code,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3830 counting only the variables that are active
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3831 in the current scope of the function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3832 Negative indices refer to vararg parameters;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3833 -1 is the first vararg parameter.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3834 The function returns <b>nil</b> if there is no variable with the given index,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3835 and raises an error when called with a level out of range.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3836 (You can call <a href="#pdf-debug.getinfo"><code>debug.getinfo</code></a> to check whether the level is valid.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3837
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3838
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3839 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3840 Variable names starting with '<code>(</code>' (open parenthesis)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3841 represent variables with no known names
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3842 (internal variables such as loop control variables,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3843 and variables from chunks saved without debug information).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3844
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3845
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3846 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3847 The parameter <code>f</code> may also be a function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3848 In that case, <code>getlocal</code> returns only the name of function parameters.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3849
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3850
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3851
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3852
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3853 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3854 <hr><h3><a name="pdf-debug.getmetatable"><code>debug.getmetatable (value)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3855
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3856
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3857 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3858 Returns the metatable of the given <code>value</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3859 or <b>nil</b> if it does not have a metatable.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3860
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3861
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3862
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3863
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3864 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3865 <hr><h3><a name="pdf-debug.getregistry"><code>debug.getregistry ()</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3866
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3867
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3868 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3869 Returns the registry table (see <a href="#4.5">&sect;4.5</a>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3870
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3871
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3872
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3873
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3874 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3875 <hr><h3><a name="pdf-debug.getupvalue"><code>debug.getupvalue (f, up)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3876
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3877
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3878 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3879 This function returns the name and the value of the upvalue
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3880 with index <code>up</code> of the function <code>f</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3881 The function returns <b>nil</b> if there is no upvalue with the given index.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3882
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3883
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3884 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3885 Variable names starting with '<code>(</code>' (open parenthesis)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3886 represent variables with no known names
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3887 (variables from chunks saved without debug information).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3888
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3889
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3890
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3891
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3892 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3893 <hr><h3><a name="pdf-debug.getuservalue"><code>debug.getuservalue (u)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3894
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3895
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3896 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3897 Returns the Lua value associated to <code>u</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3898 If <code>u</code> is not a userdata,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3899 returns <b>nil</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3900
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3901
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3902
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3903
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3904 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3905 <hr><h3><a name="pdf-debug.sethook"><code>debug.sethook ([thread,] hook, mask [, count])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3906
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3907
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3908 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3909 Sets the given function as a hook.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3910 The string <code>mask</code> and the number <code>count</code> describe
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3911 when the hook will be called.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3912 The string mask may have any combination of the following characters,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3913 with the given meaning:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3914
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3915 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3916 <li><b>'<code>c</code>': </b> the hook is called every time Lua calls a function;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3917 <li><b>'<code>r</code>': </b> the hook is called every time Lua returns from a function;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3918 <li><b>'<code>l</code>': </b> the hook is called every time Lua enters a new line of code.</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3919 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3920 Moreover,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3921 with a <code>count</code> different from zero,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3922 the hook is called also after every <code>count</code> instructions.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3923
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3924
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3925 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3926 When called without arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3927 <a href="#pdf-debug.sethook"><code>debug.sethook</code></a> turns off the hook.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3928
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3929
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3930 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3931 When the hook is called, its first parameter is a string
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3932 describing the event that has triggered its call:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3933 <code>"call"</code> (or <code>"tail call"</code>),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3934 <code>"return"</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3935 <code>"line"</code>, and <code>"count"</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3936 For line events,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3937 the hook also gets the new line number as its second parameter.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3938 Inside a hook,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3939 you can call <code>getinfo</code> with level&nbsp;2 to get more information about
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3940 the running function
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3941 (level&nbsp;0 is the <code>getinfo</code> function,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3942 and level&nbsp;1 is the hook function).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3943
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3944
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3945
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3946
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3947 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3948 <hr><h3><a name="pdf-debug.setlocal"><code>debug.setlocal ([thread,] level, local, value)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3949
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3950
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3951 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3952 This function assigns the value <code>value</code> to the local variable
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3953 with index <code>local</code> of the function at level <code>level</code> of the stack.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3954 The function returns <b>nil</b> if there is no local
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3955 variable with the given index,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3956 and raises an error when called with a <code>level</code> out of range.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3957 (You can call <code>getinfo</code> to check whether the level is valid.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3958 Otherwise, it returns the name of the local variable.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3959
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3960
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3961 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3962 See <a href="#pdf-debug.getlocal"><code>debug.getlocal</code></a> for more information about
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3963 variable indices and names.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3964
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3965
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3966
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3967
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3968 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3969 <hr><h3><a name="pdf-debug.setmetatable"><code>debug.setmetatable (value, table)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3970
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3971
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3972 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3973 Sets the metatable for the given <code>value</code> to the given <code>table</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3974 (which can be <b>nil</b>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3975 Returns <code>value</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3976
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3977
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3978
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3979
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3980 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3981 <hr><h3><a name="pdf-debug.setupvalue"><code>debug.setupvalue (f, up, value)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3982
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3983
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3984 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3985 This function assigns the value <code>value</code> to the upvalue
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3986 with index <code>up</code> of the function <code>f</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3987 The function returns <b>nil</b> if there is no upvalue
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3988 with the given index.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3989 Otherwise, it returns the name of the upvalue.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3990
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3991
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3992
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3993
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3994 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3995 <hr><h3><a name="pdf-debug.setuservalue"><code>debug.setuservalue (udata, value)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3996
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3997
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3998 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3999 Sets the given <code>value</code> as
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4000 the Lua value associated to the given <code>udata</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4001 <code>udata</code> must be a full userdata.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4002
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4003
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4004 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4005 Returns <code>udata</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4006
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4007
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4008
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4009
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4010 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4011 <hr><h3><a name="pdf-debug.traceback"><code>debug.traceback ([thread,] [message [, level]])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4012
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4013
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4014 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4015 If <code>message</code> is present but is neither a string nor <b>nil</b>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4016 this function returns <code>message</code> without further processing.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4017 Otherwise,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4018 it returns a string with a traceback of the call stack.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4019 The optional <code>message</code> string is appended
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4020 at the beginning of the traceback.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4021 An optional <code>level</code> number tells at which level
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4022 to start the traceback
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4023 (default is 1, the function calling <code>traceback</code>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4024
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4025
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4026
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4027
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4028 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4029 <hr><h3><a name="pdf-debug.upvalueid"><code>debug.upvalueid (f, n)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4030
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4031
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4032 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4033 Returns a unique identifier (as a light userdata)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4034 for the upvalue numbered <code>n</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4035 from the given function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4036
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4037
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4038 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4039 These unique identifiers allow a program to check whether different
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4040 closures share upvalues.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4041 Lua closures that share an upvalue
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4042 (that is, that access a same external local variable)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4043 will return identical ids for those upvalue indices.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4044
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4045
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4046
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4047
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4048 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4049 <hr><h3><a name="pdf-debug.upvaluejoin"><code>debug.upvaluejoin (f1, n1, f2, n2)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4050
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4051
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4052 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4053 Make the <code>n1</code>-th upvalue of the Lua closure <code>f1</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4054 refer to the <code>n2</code>-th upvalue of the Lua closure <code>f2</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4055
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4056
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4057
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4058
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4059
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4060
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4061
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4062 <h1>7 &ndash; <a name="7">Lua Standalone</a></h1>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4063
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4064 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4065 Although Lua has been designed as an extension language,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4066 to be embedded in a host C&nbsp;program,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4067 it is also frequently used as a standalone language.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4068 An interpreter for Lua as a standalone language,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4069 called simply <code>lua</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4070 is provided with the standard distribution.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4071 The standalone interpreter includes
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4072 all standard libraries, including the debug library.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4073 Its usage is:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4074
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4075 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4076 lua [options] [script [args]]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4077 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4078 The options are:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4079
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4080 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4081 <li><b><code>-e <em>stat</em></code>: </b> executes string <em>stat</em>;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4082 <li><b><code>-l <em>mod</em></code>: </b> "requires" <em>mod</em>;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4083 <li><b><code>-i</code>: </b> enters interactive mode after running <em>script</em>;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4084 <li><b><code>-v</code>: </b> prints version information;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4085 <li><b><code>-E</code>: </b> ignores environment variables;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4086 <li><b><code>--</code>: </b> stops handling options;</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4087 <li><b><code>-</code>: </b> executes <code>stdin</code> as a file and stops handling options.</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4088 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4089 After handling its options, <code>lua</code> runs the given <em>script</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4090 When called without arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4091 <code>lua</code> behaves as <code>lua -v -i</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4092 when the standard input (<code>stdin</code>) is a terminal,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4093 and as <code>lua -</code> otherwise.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4094
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4095
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4096 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4097 When called without option <code>-E</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4098 the interpreter checks for an environment variable <a name="pdf-LUA_INIT_5_3"><code>LUA_INIT_5_3</code></a>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4099 (or <a name="pdf-LUA_INIT"><code>LUA_INIT</code></a> if the versioned name is not defined)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4100 before running any argument.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4101 If the variable content has the format <code>@<em>filename</em></code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4102 then <code>lua</code> executes the file.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4103 Otherwise, <code>lua</code> executes the string itself.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4104
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4105
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4106 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4107 When called with option <code>-E</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4108 besides ignoring <code>LUA_INIT</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4109 Lua also ignores
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4110 the values of <code>LUA_PATH</code> and <code>LUA_CPATH</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4111 setting the values of
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4112 <a href="#pdf-package.path"><code>package.path</code></a> and <a href="#pdf-package.cpath"><code>package.cpath</code></a>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4113 with the default paths defined in <code>luaconf.h</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4114
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4115
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4116 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4117 All options are handled in order, except <code>-i</code> and <code>-E</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4118 For instance, an invocation like
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4119
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4120 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4121 $ lua -e'a=1' -e 'print(a)' script.lua
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4122 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4123 will first set <code>a</code> to 1, then print the value of <code>a</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4124 and finally run the file <code>script.lua</code> with no arguments.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4125 (Here <code>$</code> is the shell prompt. Your prompt may be different.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4126
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4127
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4128 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4129 Before running any code,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4130 <code>lua</code> collects all command-line arguments
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4131 in a global table called <code>arg</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4132 The script name goes to index 0,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4133 the first argument after the script name goes to index 1,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4134 and so on.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4135 Any arguments before the script name
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4136 (that is, the interpreter name plus its options)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4137 go to negative indices.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4138 For instance, in the call
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4139
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4140 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4141 $ lua -la b.lua t1 t2
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4142 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4143 the table is like this:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4144
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4145 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4146 arg = { [-2] = "lua", [-1] = "-la",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4147 [0] = "b.lua",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4148 [1] = "t1", [2] = "t2" }
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4149 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4150 If there is no script in the call,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4151 the interpreter name goes to index 0,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4152 followed by the other arguments.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4153 For instance, the call
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4154
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4155 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4156 $ lua -e "print(arg[1])"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4157 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4158 will print "<code>-e</code>".
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4159 If there is a script,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4160 the script is called with parameters
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4161 <code>arg[1]</code>, &middot;&middot;&middot;, <code>arg[#arg]</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4162 (Like all chunks in Lua,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4163 the script is compiled as a vararg function.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4164
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4165
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4166 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4167 In interactive mode,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4168 Lua repeatedly prompts and waits for a line.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4169 After reading a line,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4170 Lua first try to interpret the line as an expression.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4171 If it succeeds, it prints its value.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4172 Otherwise, it interprets the line as a statement.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4173 If you write an incomplete statement,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4174 the interpreter waits for its completion
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4175 by issuing a different prompt.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4176
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4177
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4178 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4179 In case of unprotected errors in the script,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4180 the interpreter reports the error to the standard error stream.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4181 If the error object is not a string but
429
e3a6d9dbd694 rename __tostring to __to_string
Franklin Schmidt <fschmidt@gmail.com>
parents: 428
diff changeset
4182 has a metamethod <code>__to_string</code>,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4183 the interpreter calls this metamethod to produce the final message.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4184 Otherwise, the interpreter converts the error object to a string
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4185 and adds a stack traceback to it.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4186
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4187
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4188 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4189 When finishing normally,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4190 the interpreter closes its main Lua state
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4191 (see <a href="#lua_close"><code>lua_close</code></a>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4192 The script can avoid this step by
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4193 calling <a href="#pdf-os.exit"><code>os.exit</code></a> to terminate.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4194
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4195
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4196 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4197 To allow the use of Lua as a
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4198 script interpreter in Unix systems,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4199 the standalone interpreter skips
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4200 the first line of a chunk if it starts with <code>#</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4201 Therefore, Lua scripts can be made into executable programs
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4202 by using <code>chmod +x</code> and the&nbsp;<code>#!</code> form,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4203 as in
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4204
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4205 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4206 #!/usr/local/bin/lua
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4207 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4208 (Of course,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4209 the location of the Lua interpreter may be different in your machine.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4210 If <code>lua</code> is in your <code>PATH</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4211 then
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4212
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4213 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4214 #!/usr/bin/env lua
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4215 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4216 is a more portable solution.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4217
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4218
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4219
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4220 <h1>8 &ndash; <a name="8">Incompatibilities with the Previous Version</a></h1>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4221
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4222 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4223 Here we list the incompatibilities that you may find when moving a program
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4224 from Lua&nbsp;5.2 to Lua&nbsp;5.3.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4225 You can avoid some incompatibilities by compiling Lua with
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4226 appropriate options (see file <code>luaconf.h</code>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4227 However,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4228 all these compatibility options will be removed in the future.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4229
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4230
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4231 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4232 Lua versions can always change the C API in ways that
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4233 do not imply source-code changes in a program,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4234 such as the numeric values for constants
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4235 or the implementation of functions as macros.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4236 Therefore,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4237 you should not assume that binaries are compatible between
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4238 different Lua versions.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4239 Always recompile clients of the Lua API when
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4240 using a new version.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4241
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4242
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4243 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4244 Similarly, Lua versions can always change the internal representation
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4245 of precompiled chunks;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4246 precompiled chunks are not compatible between different Lua versions.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4247
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4248
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4249 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4250 The standard paths in the official distribution may
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4251 change between versions.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4252
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4253
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4254
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4255 <h2>8.1 &ndash; <a name="8.1">Changes in the Language</a></h2>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4256 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4257
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4258 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4259 The main difference between Lua&nbsp;5.2 and Lua&nbsp;5.3 is the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4260 introduction of an integer subtype for numbers.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4261 Although this change should not affect "normal" computations,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4262 some computations
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4263 (mainly those that involve some kind of overflow)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4264 can give different results.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4265
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4266
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4267 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4268 You can fix these differences by forcing a number to be a float
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4269 (in Lua&nbsp;5.2 all numbers were float),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4270 in particular writing constants with an ending <code>.0</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4271 or using <code>x = x + 0.0</code> to convert a variable.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4272 (This recommendation is only for a quick fix
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4273 for an occasional incompatibility;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4274 it is not a general guideline for good programming.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4275 For good programming,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4276 use floats where you need floats
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4277 and integers where you need integers.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4278 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4279
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4280 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4281 The conversion of a float to a string now adds a <code>.0</code> suffix
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4282 to the result if it looks like an integer.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4283 (For instance, the float 2.0 will be printed as <code>2.0</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4284 not as <code>2</code>.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4285 You should always use an explicit format
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4286 when you need a specific format for numbers.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4287
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4288
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4289 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4290 (Formally this is not an incompatibility,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4291 because Lua does not specify how numbers are formatted as strings,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4292 but some programs assumed a specific format.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4293 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4294
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4295 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4296 The generational mode for the garbage collector was removed.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4297 (It was an experimental feature in Lua&nbsp;5.2.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4298 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4299
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4300 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4301
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4302
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4303
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4304
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4305 <h2>8.2 &ndash; <a name="8.2">Changes in the Libraries</a></h2>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4306 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4307
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4308 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4309 The <code>bit32</code> library has been deprecated.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4310 It is easy to require a compatible external library or,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4311 better yet, to replace its functions with appropriate bitwise operations.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4312 (Keep in mind that <code>bit32</code> operates on 32-bit integers,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4313 while the bitwise operators in standard Lua operate on 64-bit integers.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4314 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4315
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4316 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4317 The Table library now respects metamethods
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4318 for setting and getting elements.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4319 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4320
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4321 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4322 The <a href="#pdf-ipairs"><code>ipairs</code></a> iterator now respects metamethods and
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4323 its <code>__ipairs</code> metamethod has been deprecated.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4324 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4325
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4326 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4327 Option names in <a href="#pdf-io.read"><code>io.read</code></a> do not have a starting '<code>*</code>' anymore.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4328 For compatibility, Lua will continue to ignore this character.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4329 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4330
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4331 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4332 The following functions were deprecated in the mathematical library:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4333 <code>atan2</code>, <code>cosh</code>, <code>sinh</code>, <code>tanh</code>, <code>pow</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4334 <code>frexp</code>, and <code>ldexp</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4335 You can replace <code>math.pow(x,y)</code> with <code>x^y</code>;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4336 you can replace <code>math.atan2</code> with <code>math.atan</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4337 which now accepts one or two parameters;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4338 you can replace <code>math.ldexp(x,exp)</code> with <code>x * 2.0^exp</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4339 For the other operations,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4340 you can either use an external library or
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4341 implement them in Lua.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4342 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4343
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4344 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4345 The searcher for C loaders used by <a href="#pdf-require"><code>require</code></a>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4346 changed the way it handles versioned names.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4347 Now, the version should come after the module name
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4348 (as is usual in most other tools).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4349 For compatibility, that searcher still tries the old format
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4350 if it cannot find an open function according to the new style.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4351 (Lua&nbsp;5.2 already worked that way,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4352 but it did not document the change.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4353 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4354
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4355 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4356
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4357
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4358
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4359
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4360 <h2>8.3 &ndash; <a name="8.3">Changes in the API</a></h2>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4361
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4362
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4363 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4364
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4365 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4366 Continuation functions now receive as parameters what they needed
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4367 to get through <code>lua_getctx</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4368 so <code>lua_getctx</code> has been removed.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4369 Adapt your code accordingly.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4370 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4372 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4373 Function <a href="#lua_dump"><code>lua_dump</code></a> has an extra parameter, <code>strip</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4374 Use 0 as the value of this parameter to get the old behavior.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4375 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4376
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4377 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4378 Functions to inject/project unsigned integers
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4379 (<code>lua_pushunsigned</code>, <code>lua_tounsigned</code>, <code>lua_tounsignedx</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4380 <code>luaL_checkunsigned</code>, <code>luaL_optunsigned</code>)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4381 were deprecated.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4382 Use their signed equivalents with a type cast.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4383 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4384
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4385 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4386 Macros to project non-default integer types
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4387 (<code>luaL_checkint</code>, <code>luaL_optint</code>, <code>luaL_checklong</code>, <code>luaL_optlong</code>)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4388 were deprecated.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4389 Use their equivalent over <a href="#lua_Integer"><code>lua_Integer</code></a> with a type cast
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4390 (or, when possible, use <a href="#lua_Integer"><code>lua_Integer</code></a> in your code).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4391 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4392
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4393 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4394
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4395
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4396
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4397
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4398 <h1>9 &ndash; <a name="9">The Complete Syntax of Lua</a></h1>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4399
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4400 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4401 Here is the complete syntax of Lua in extended BNF.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4402 As usual in extended BNF,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4403 {A} means 0 or more As,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4404 and [A] means an optional A.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4405 (For operator precedences, see <a href="#3.4.8">&sect;3.4.8</a>;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4406 for a description of the terminals
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4407 Name, Numeral,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4408 and LiteralString, see <a href="#3.1">&sect;3.1</a>.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4409
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4410
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4411
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4412
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4413 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4414
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4415 chunk ::= block
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4416
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4417 block ::= {stat} [retstat]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4418
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4419 stat ::= &lsquo;<b>;</b>&rsquo; |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4420 varlist &lsquo;<b>=</b>&rsquo; explist |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4421 functioncall |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4422 label |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4423 <b>break</b> |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4424 <b>goto</b> Name |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4425 <b>do</b> block <b>end</b> |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4426 <b>while</b> exp <b>do</b> block <b>end</b> |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4427 <b>repeat</b> block <b>until</b> exp |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4428 <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] <b>end</b> |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4429 <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> |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4430 <b>for</b> namelist <b>in</b> explist <b>do</b> block <b>end</b> |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4431 <b>function</b> funcname funcbody |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4432 <b>local</b> <b>function</b> Name funcbody |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4433 <b>local</b> namelist [&lsquo;<b>=</b>&rsquo; explist]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4434
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4435 retstat ::= <b>return</b> [explist] [&lsquo;<b>;</b>&rsquo;]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4436
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4437 label ::= &lsquo;<b>::</b>&rsquo; Name &lsquo;<b>::</b>&rsquo;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4438
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4439 funcname ::= Name {&lsquo;<b>.</b>&rsquo; Name} [&lsquo;<b>:</b>&rsquo; Name]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4440
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4441 varlist ::= var {&lsquo;<b>,</b>&rsquo; var}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4442
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4443 var ::= Name | prefixexp &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo; | prefixexp &lsquo;<b>.</b>&rsquo; Name
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4444
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4445 namelist ::= Name {&lsquo;<b>,</b>&rsquo; Name}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4446
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4447 explist ::= exp {&lsquo;<b>,</b>&rsquo; exp}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4448
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4449 exp ::= <b>nil</b> | <b>false</b> | <b>true</b> | Numeral | LiteralString | &lsquo;<b>...</b>&rsquo; | functiondef |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4450 prefixexp | tableconstructor | exp binop exp | unop exp
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4451
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4452 prefixexp ::= var | functioncall | &lsquo;<b>(</b>&rsquo; exp &lsquo;<b>)</b>&rsquo;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4453
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4454 functioncall ::= prefixexp args | prefixexp &lsquo;<b>:</b>&rsquo; Name args
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4455
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4456 args ::= &lsquo;<b>(</b>&rsquo; [explist] &lsquo;<b>)</b>&rsquo; | tableconstructor | LiteralString
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4457
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4458 functiondef ::= <b>function</b> funcbody
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4459
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4460 funcbody ::= &lsquo;<b>(</b>&rsquo; [parlist] &lsquo;<b>)</b>&rsquo; block <b>end</b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4461
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4462 parlist ::= namelist [&lsquo;<b>,</b>&rsquo; &lsquo;<b>...</b>&rsquo;] | &lsquo;<b>...</b>&rsquo;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4463
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4464 tableconstructor ::= &lsquo;<b>{</b>&rsquo; [fieldlist] &lsquo;<b>}</b>&rsquo;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4465
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4466 fieldlist ::= field {fieldsep field} [fieldsep]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4467
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4468 field ::= &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo; &lsquo;<b>=</b>&rsquo; exp | Name &lsquo;<b>=</b>&rsquo; exp | exp
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4469
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4470 fieldsep ::= &lsquo;<b>,</b>&rsquo; | &lsquo;<b>;</b>&rsquo;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4471
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4472 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; |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4473 &lsquo;<b>&amp;</b>&rsquo; | &lsquo;<b>~</b>&rsquo; | &lsquo;<b>|</b>&rsquo; | &lsquo;<b>&gt;&gt;</b>&rsquo; | &lsquo;<b>&lt;&lt;</b>&rsquo; | &lsquo;<b>..</b>&rsquo; |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4474 &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; |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4475 <b>and</b> | <b>or</b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4476
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4477 unop ::= &lsquo;<b>-</b>&rsquo; | <b>not</b> | &lsquo;<b>#</b>&rsquo; | &lsquo;<b>~</b>&rsquo;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4478
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4479 </pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4480
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4481 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4482
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4483
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4484
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4485
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4486
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4487
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4488
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4489
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4490 <HR>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4491 <SMALL CLASS="footer">
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4492 Last update:
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4493 Fri Jan 16 00:58:20 BRST 2015
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4494 </SMALL>
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f08cefa4594c start editing manual
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4499 </div>
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4501 </body>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom
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4502 </html>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom
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4503 <%
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