annotate website/src/manual.html.luan @ 470:5627eb637eb4

documentation
author Franklin Schmidt <fschmidt@gmail.com>
date Sat, 09 May 2015 23:54:22 -0600
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1 local Io = require "luan:Io"
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2 local Html = require "luan:Html"
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3 local Http = require "luan:web/Http"
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4 local Shared = require "site:/Shared"
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7 function service()
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8 Io.stdout = Http.response.text_writer()
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9 %>
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10 <html>
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11 <head>
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12 <% Html.simply_html_head() %>
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13 <title>Luan Reference Manual</title>
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14 </head>
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15 <body>
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17 <div container>
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18 <% Shared.header() %>
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19
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20 <h1>Luan Reference Manual</h1>
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21
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22 <p>
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23 <small>
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24 Original copyright &copy; 2015 Lua.org, PUC-Rio.
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25 Freely available under the terms of the
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26 <a href="http://www.lua.org/license.html">Lua license</a>.
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27 Modified for Luan.
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28 </small>
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29 </p>
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30
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31 <hr/>
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32
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33 <h2>Contents</h2>
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34
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35 <div margin-bottom="1em"><a href="#intro">Introduction</a></div>
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37 <div margin-bottom="1em">
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38 <a href="#basic">Basic Concepts</a>
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39 <ul>
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40 <li><a href="#types">Values and Types</a></li>
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41 <li><a href="#env">Environments</a></li>
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42 <li><a href="#error">Error Handling</a></li>
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43 <li><a href="#meta">Metatables and Metamethods</a></li>
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44 <li><a href="#gc">Garbage Collection</a></li>
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45 </ul>
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46 </div>
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47
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48 <div margin-bottom="1em">
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49 <a href="#lang">The Language</a>
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50 <ul>
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51 <li><a href="#lex">Lexical Conventions</a></li>
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52 <li><a href="#vars">Variables</a></li>
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53 <li>
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54 <a href="#stmts">Statements</a>
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55 <ul>
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56 <li><a href="#blocks">Blocks</a></li>
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57 <li><a href="#chunks">Chunks</a></li>
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58 <li><a href="#assignment">Assignment</a></li>
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59 <li><a href="#control">Control Structures</a></li>
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60 <li><a href="#for">For Statement</a></li>
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61 <li><a href="#fn_stmt">Function Calls as Statements</a></li>
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62 <li><a href="#local_stmt">Local Declarations</a></li>
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63 <li><a href="#template_stmt">Template Statements</a></li>
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64 </ul>
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65 </li>
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66 <li>
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67 <a href="#expressions">Expressions</a>
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68 <ul>
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69 <li><a href="#arithmetic">Arithmetic Operators</a></li>
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70 <li><a href="#conversions">Coercions and Conversions</a></li>
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71 <li><a href="#relational">Relational Operators</a></li>
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72 <li><a href="#logical_ops">Logical Operators</a></li>
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73 <li><a href="#concatenation">Concatenation</a></li>
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74 <li><a href="#length">The Length Operator</a></li>
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75 <li><a href="#precedence">Precedence</a></li>
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76 <li><a href="#constructors">Table Constructors</a></li>
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77 <li><a href="#fn_calls">Function Calls</a></li>
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78 <li><a href="#fn_def">Function Definitions</a></li>
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79 <li><a href="#template_expr">Template Expressions</a></li>
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80 </ul>
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81 </li>
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82 <li><a href="#visibility">Visibility Rules</a></li>
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83 </ul>
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84 </div>
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85
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86 <div margin-bottom="1em">
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87 <a href="#libs">Standard Libraries</a>
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88 <ul>
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89 <li><a href="#default_lib">Default Environment</a></li>
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90 <li><a href="#luan_lib">Basic Functions</a></li>
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91 </ul>
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92 </div>
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93
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94 <hr/>
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95
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96
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97 <h2 margin-top="1em"><a name="intro">Introduction</a></h2>
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98
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99 <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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100
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101 <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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102
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103 <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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105
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106 <h2 margin-top="1em"><a name="basic">Basic Concepts</a></h2>
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107
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108 <p>This section describes the basic concepts of the language.</p>
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109
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110 <h3 margin-top="1em"><a name="types">Values and Types</a></h3>
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111
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112 <p>
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113 Luan is a <i>dynamically typed language</i>.
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114 This means that
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115 variables do not have types; only values do.
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116 There are no type definitions in the language.
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117 All values carry their own type.
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120 <p>
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121 All values in Luan are <i>first-class values</i>.
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122 This means that all values can be stored in variables,
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123 passed as arguments to other functions, and returned as results.
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126 <p>
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127 There are eight basic types in Luan:
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128 <i>nil</i>, <i>boolean</i>, <i>number</i>,
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129 <i>string</i>, <i>binary</i>, <i>function</i>, <i>userdata</i>,
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130 and <i>table</i>.
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131 <i>Nil</i> is the type of the value <b>nil</b>,
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132 whose main property is to be different from any other value;
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133 it usually represents the absence of a useful value.
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134 <i>Nil</i> is implemented as the Java value <i>null</i>.
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135 <i>Boolean</i> is the type of the values <b>false</b> and <b>true</b>.
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136 <i>Boolean</i> is implemented as the Java class <i>Boolean</i>.
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137 <i>Number</i> represents both
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138 integer numbers and real (floating-point) numbers.
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139 <i>Number</i> is implemented as the Java class <i>Number</i>. Any Java subclass of <i>Number</i> is allowed and this is invisible to the Luan user. Operations on numbers follow the same rules of
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140 the underlying Java implementation.
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141
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142 <i>String</i> is implemented as the Java class <i>String</i>.
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143 <i>Binary</i> is implemented as the Java type <i>byte[]</i>.
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144
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145
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146 <p>
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147 Luan can call (and manipulate) functions written in Luan and
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148 functions written in Java (see <a href="#fn_calls">Function Calls</a>).
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149 Both are represented by the type <i>function</i>.
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150
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151
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152 <p>
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153 The type <i>userdata</i> is provided to allow arbitrary Java objects to
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154 be stored in Luan variables.
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155 A userdata value is a Java object that isn't one of the standard Luan types.
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156 Userdata has no predefined operations in Luan,
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157 except assignment and identity test.
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158 Userdata is useful then Java access is enabled in Luan
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159
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160
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161
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162 <p>
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163 The type <i>table</i> implements associative arrays,
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164 that is, arrays that can be indexed not only with numbers,
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165 but with any Luan value except <b>nil</b>.
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166 Tables can be <i>heterogeneous</i>;
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167 that is, they can contain values of all types (except <b>nil</b>).
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168 Any key with value <b>nil</b> is not considered part of the table.
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169 Conversely, any key that is not part of a table has
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170 an associated value <b>nil</b>.
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171
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172
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173 <p>
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174 Tables are the sole data-structuring mechanism in Luan;
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175 they can be used to represent ordinary arrays, sequences,
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176 symbol tables, sets, records, graphs, trees, etc.
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177 To represent records, Luan uses the field name as an index.
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178 The language supports this representation by
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179 providing <tt>a.name</tt> as syntactic sugar for <tt>a["name"]</tt>.
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180 There are several convenient ways to create tables in Luan
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181 (see <a href="#constructors">Table Constructors</a>).
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182
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183
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184 <p>
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185 We use the term <i>sequence</i> to denote a table where
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186 the set of all positive numeric keys is equal to {1..<i>n</i>}
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187 for some non-negative integer <i>n</i>,
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188 which is called the length of the sequence (see <a href="#length">The Length Operator</a>).
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189
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190
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191 <p>
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192 Like indices,
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193 the values of table fields can be of any type.
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194 In particular,
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195 because functions are first-class values,
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196 table fields can contain functions.
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197 Thus tables can also carry <i>methods</i> (see <a href="#fn_def">Function Definitions</a>).
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198
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199
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200 <p>
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201 The indexing of tables follows
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202 the definition of raw equality in the language.
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203 The expressions <tt>a[i]</tt> and <tt>a[j]</tt>
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204 denote the same table element
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205 if and only if <tt>i</tt> and <tt>j</tt> are raw equal
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206 (that is, equal without metamethods).
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207 In particular, floats with integral values
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208 are equal to their respective integers
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209 (e.g., <tt>1.0 == 1</tt>).
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210
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211
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212 <p>
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213 Luan values are <i>objects</i>:
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214 variables do not actually <i>contain</i> values,
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215 only <i>references</i> to them.
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216 Assignment, parameter passing, and function returns
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217 always manipulate references to values;
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218 these operations do not imply any kind of copy.
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219
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220
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221 <p>
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222 The library function <a href="#pdf-type"><tt>Luan.type</tt></a> returns a string describing the type
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223 of a given value (see <a href="#6.1">&sect;6.1</a>).
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224
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225
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226
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227
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228
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229 <h3 margin-top="1em"><a name="env">Environments</a></h3>
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230
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231 <p>
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232 As will be discussed in <a href="#vars">Variables</a> and <a href=#assignment">Assignment</a>,
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233 any reference to a free name
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234 (that is, a name not bound to any declaration) <tt>var</tt>
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235 is syntactically translated to <tt>_ENV.var</tt>.
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236 Moreover, every chunk is compiled in the scope of
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237 an external local variable named <tt>_ENV</tt> (see <a href="#chunks">Chunks</a>),
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238 so <tt>_ENV</tt> itself is never a free name in a chunk.
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239
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240
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241 <p>
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242 Despite the existence of this external <tt>_ENV</tt> variable and
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243 the translation of free names,
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244 <tt>_ENV</tt> is a completely regular name.
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245 In particular,
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246 you can define new variables and parameters with that name.
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247 Each reference to a free name uses the <tt>_ENV</tt> that is
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248 visible at that point in the program,
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249 following the usual visibility rules of Luan (see <a href="#visibility">Visibility Rules</a>).
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250
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251
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252 <p>
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253 Any table used as the value of <tt>_ENV</tt> is called an <i>environment</i>.
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254
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255
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256 <p>
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257 When Luan loads a chunk,
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258 the default value for its <tt>_ENV</tt> is an empty table.
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259
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260 <p>
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261 Luan also provides all chunks with two other local values: <tt>require</tt> and <tt>java</tt>. These are functions used to load and access libraries and other modules.
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262
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263
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264
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265
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266 <h3 margin-top="1em"><a name="error">Error Handling</a></h3>
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267
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268 <p>
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269 Luan code can explicitly generate an error by calling the
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270 <a href="#pdf-error"><tt>error</tt></a> function.
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271 If you need to catch errors in Luan,
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272 you can use <a href="#pdf-pcall"><tt>pcall</tt></a> or <a href="#pdf-xpcall"><tt>try</tt></a>
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273 to call a given function in <i>protected mode</i>.
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274
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275
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276 <p>
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277 Whenever there is an error,
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278 an <i>error object</i> (also called an <i>error message</i>)
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279 is propagated with information about the error.
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280 Luan itself only generates errors whose error object is a string,
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281 but programs may generate errors with
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282 any value as the error object.
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283 It is up to the Luan program or its host to handle such error objects.
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284
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285
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286
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287
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288
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289 <h3 margin-top="1em"><a name="meta">Metatables and Metamethods</a></h3>
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290
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291 <p>
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292 Every table in Luan can have a <i>metatable</i>.
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293 This <i>metatable</i> is an ordinary Luan table
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294 that defines the behavior of the original value
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295 under certain special operations.
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296 You can change several aspects of the behavior
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297 of operations over a value by setting specific fields in its metatable.
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298 For instance, when a table is the operand of an addition,
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299 Luan checks for a function in the field "<tt>__add</tt>" of the table's metatable.
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300 If it finds one,
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301 Luan calls this function to perform the addition.
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302
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303
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304 <p>
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305 The keys in a metatable are derived from the <i>event</i> names;
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306 the corresponding values are called <ii>metamethods</i>.
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307 In the previous example, the event is <tt>"add"</tt>
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308 and the metamethod is the function that performs the addition.
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309
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310
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311 <p>
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312 You can query the metatable of any table
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313 using the <a href="#pdf-getmetatable"><tt>get_metatable</tt></a> function.
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314
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315
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316 <p>
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317 You can replace the metatable of tables
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318 using the <a href="#pdf-setmetatable"><tt>set_metatable</tt></a> function.
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319
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320
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321 <p>
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322 A metatable controls how a table behaves in
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323 arithmetic operations, bitwise operations,
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324 order comparisons, concatenation, length operation, calls, and indexing.
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325
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326
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327 <p>
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328 A detailed list of events controlled by metatables is given next.
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329 Each operation is identified by its corresponding event name.
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330 The key for each event is a string with its name prefixed by
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331 two underscores, '<tt>__</tt>';
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332 for instance, the key for operation "add" is the
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333 string "<tt>__add</tt>".
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334 Note that queries for metamethods are always raw;
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335 the access to a metamethod does not invoke other metamethods.
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336 You can emulate how Luan queries a metamethod for an object <tt>obj</tt>
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337 with the following code:
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338
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339 <p><tt><pre>
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340 raw_get(get_metatable(obj) or {}, "__" .. event_name)
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341 </pre></tt></p>
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342
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343 <p>
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344 Here are the events:
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345
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346 <ul>
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347
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348 <li><b>"add": </b>
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349 the <tt>+</tt> operation.
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350
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351 If any operand for an addition is a table,
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352 Luan will try to call a metamethod.
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353 First, Luan will check the first operand (even if it is valid).
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354 If that operand does not define a metamethod for the "<tt>__add</tt>" event,
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355 then Luan will check the second operand.
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356 If Luan can find a metamethod,
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357 it calls the metamethod with the two operands as arguments,
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358 and the result of the call
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359 (adjusted to one value)
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360 is the result of the operation.
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361 Otherwise,
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362 it raises an error.
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363 </li>
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364
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365 <li><b>"sub": </b>
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366 the <tt>-</tt> operation.
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367
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368 Behavior similar to the "add" operation.
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369 </li>
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370
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371 <li><b>"mul": </b>
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372 the <tt>*</tt> operation.
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373
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374 Behavior similar to the "add" operation.
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375 </li>
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376
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377 <li><b>"div": </b>
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378 the <tt>/</tt> operation.
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379
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380 Behavior similar to the "add" operation.
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381 </li>
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382
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383 <li><b>"mod": </b>
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384 the <tt>%</tt> operation.
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385
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386 Behavior similar to the "add" operation.
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387 </li>
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388
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389 <li><b>"pow": </b>
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390 the <tt>^</tt> (exponentiation) operation.
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391
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392 Behavior similar to the "add" operation.
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393 </li>
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394
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395 <li><b>"unm": </b>
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396 the <tt>-</tt> (unary minus) operation.
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397
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398 Behavior similar to the "add" operation.
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399 </li>
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400
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401 <li><b>"concat": </b>
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402 the <tt>..</tt> (concatenation) operation.
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403
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404 Behavior similar to the "add" operation.
371
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405 </li>
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406
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407 <li><b>"len": </b>
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408 the <tt>#</tt> (length) operation.
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409
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410 If there is a metamethod,
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411 Luan calls it with the object as argument,
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412 and the result of the call
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413 (always adjusted to one value)
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414 is the result of the operation.
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415 If there is no metamethod but the object is a table,
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416 then Luan uses the table length operation (see <a href="#length">The Length Operator</a>).
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417 Otherwise, Luan raises an error.
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418 </li>
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419
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420 <li><b>"eq": </b>
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421 the <tt>==</tt> (equal) operation.
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422
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423 Behavior similar to the "add" operation,
373
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424 except that Luan will try a metamethod only when the values
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425 being compared are both tables
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426 and they are not primitively equal.
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427 The result of the call is always converted to a boolean.
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428 </li>
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429
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430 <li><b>"lt": </b>
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431 the <tt>&lt;</tt> (less than) operation.
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432
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433 Behavior similar to the "add" operation.
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434 The result of the call is always converted to a boolean.
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435 </li>
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436
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437 <li><b>"le": </b>
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438 the <tt>&lt;=</tt> (less equal) operation.
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439
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440 Unlike other operations,
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441 The less-equal operation can use two different events.
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442 First, Luan looks for the "<tt>__le</tt>" metamethod in both operands,
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443 like in the "lt" operation.
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444 If it cannot find such a metamethod,
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445 then it will try the "<tt>__lt</tt>" event,
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446 assuming that <tt>a &lt;= b</tt> is equivalent to <tt>not (b &lt; a)</tt>.
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447 As with the other comparison operators,
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448 the result is always a boolean.
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449 </li>
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450
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451 <li><b>"index": </b>
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452 The indexing access <tt>table[key]</tt>.
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453
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454 This event happens
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455 when <tt>key</tt> is not present in <tt>table</tt>.
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456 The metamethod is looked up in <tt>table</tt>.
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457
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458
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459 <p>
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460 Despite the name,
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461 the metamethod for this event can be either a function or a table.
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462 If it is a function,
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463 it is called with <tt>table</tt> and <tt>key</tt> as arguments.
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464 If it is a table,
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465 the final result is the result of indexing this table with <tt>key</tt>.
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466 (This indexing is regular, not raw,
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467 and therefore can trigger another metamethod.)
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468 </li>
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469
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470 <li><b>"new_index": </b>
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471 The indexing assignment <tt>table[key] = value</tt>.
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472
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473 Like the index event,
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474 this event happens when
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475 when <tt>key</tt> is not present in <tt>table</tt>.
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476 The metamethod is looked up in <tt>table</tt>.
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477
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478
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479 <p>
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480 Like with indexing,
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481 the metamethod for this event can be either a function or a table.
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482 If it is a function,
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483 it is called with <tt>table</tt>, <tt>key</tt>, and <tt>value</tt> as arguments.
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484 If it is a table,
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485 Luan does an indexing assignment to this table with the same key and value.
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486 (This assignment is regular, not raw,
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487 and therefore can trigger another metamethod.)
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488
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489
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490 <p>
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491 Whenever there is a "new_index" metamethod,
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492 Luan does not perform the primitive assignment.
371
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493 (If necessary,
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494 the metamethod itself can call <a href="#pdf-rawset"><tt>raw_set</tt></a>
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495 to do the assignment.)
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496 </li>
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497
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498 <li><b>"call": </b>
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499 The call operation <tt>func(args)</tt>.
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500
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501 This event happens when Luan tries to call a table.
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502 The metamethod is looked up in <tt>func</tt>.
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503 If present,
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504 the metamethod is called with <tt>func</tt> as its first argument,
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505 followed by the arguments of the original call (<tt>args</tt>).
371
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506 </li>
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507
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508 </ul>
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509
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510
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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511
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512
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513 <h3 margin-top="1em"><a name="gc">Garbage Collection</a></h3>
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514
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515 <p>
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516 Luan uses Java's garbage collection.
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517
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diff changeset
518
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diff changeset
519
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diff changeset
520
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521
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522 <h2 margin-top="1em"><a name="lang">The Language</a></h2>
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523
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524 <p>
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525 This section describes the lexis, the syntax, and the semantics of Luan.
371
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526 In other words,
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527 this section describes
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528 which tokens are valid,
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529 how they can be combined,
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530 and what their combinations mean.
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531
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532
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533 <p>
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534 Language constructs will be explained using the usual extended BNF notation,
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535 in which
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536 {<i>a</i>}&nbsp;means&nbsp;0 or more <i>a</i>'s, and
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537 [<i>a</i>]&nbsp;means an optional <i>a</i>.
371
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538 Non-terminals are shown like non-terminal,
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539 keywords are shown like <b>kword</b>,
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540 and other terminal symbols are shown like &lsquo;<b>=</b>&rsquo;.
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541 The complete syntax of Luan can be found in <a href="#9">&sect;9</a>
371
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542 at the end of this manual.
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543
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544
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545
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546 <h3 margin-top="1em"><a name="lex">Lexical Conventions</a></h3>
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547
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548 <p>
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549 Luan ignores spaces and comments
371
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550 between lexical elements (tokens),
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551 except as delimiters between names and keywords.
380
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552 Luan generally considers the end of a line to be the end of a statement. This catches errors and encourages readability. The exception to this is in paranthesis ( <i>(...)</i>, <i>[...]</i>, and <i>{...}</i> ) where the end of line is treated as white space.
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553
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554 <p>
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555 <i>Names</i>
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556 (also called <i>identifiers</i>)
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557 in Luan can be any string of letters,
371
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558 digits, and underscores,
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559 not beginning with a digit.
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560 Identifiers are used to name variables, table fields, and labels.
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diff changeset
561
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562
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563 <p>
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564 The following <i>keywords</i> are reserved
371
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565 and cannot be used as names:
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566
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567
389
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568 <p><tt><pre>
371
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569 and break do else elseif end
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570 false for function goto if in
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571 local nil not or repeat return
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572 then true until while
389
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573 </pre></tt></p>
371
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574
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575 <p>
380
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576 Luan is a case-sensitive language:
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577 <tt>and</tt> is a reserved word, but <tt>And</tt> and <tt>AND</tt>
371
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578 are two different, valid names.
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diff changeset
579
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parents:
diff changeset
580
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parents:
diff changeset
581 <p>
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582 The following strings denote other tokens:
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583
389
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584 <p><tt><pre>
371
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585 + - * / % ^ #
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586 &amp; ~ | &lt;&lt; &gt;&gt; //
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587 == ~= &lt;= &gt;= &lt; &gt; =
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588 ( ) { } [ ] ::
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589 ; : , . .. ...
389
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diff changeset
590 </pre></tt></p>
371
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591
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592 <p>
380
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593 <i>Literal strings</i>
371
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594 can be delimited by matching single or double quotes,
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595 and can contain the following C-like escape sequences:
380
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596 '<tt>\a</tt>' (bell),
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597 '<tt>\b</tt>' (backspace),
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598 '<tt>\f</tt>' (form feed),
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599 '<tt>\n</tt>' (newline),
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600 '<tt>\r</tt>' (carriage return),
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601 '<tt>\t</tt>' (horizontal tab),
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602 '<tt>\v</tt>' (vertical tab),
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603 '<tt>\\</tt>' (backslash),
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604 '<tt>\"</tt>' (quotation mark [double quote]),
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605 and '<tt>\'</tt>' (apostrophe [single quote]).
371
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606 A backslash followed by a real newline
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607 results in a newline in the string.
380
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diff changeset
608 The escape sequence '<tt>\z</tt>' skips the following span
371
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609 of white-space characters,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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610 including line breaks;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
611 it is particularly useful to break and indent a long literal string
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
612 into multiple lines without adding the newlines and spaces
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
613 into the string contents.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
614
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
615
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diff changeset
616 <p>
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617 Luan can specify any character in a literal string by its numerical value.
371
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618 This can be done
380
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diff changeset
619 with the escape sequence <tt>\x<i>XX</i></tt>,
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diff changeset
620 where <i>XX</i> is a sequence of exactly two hexadecimal digits,
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diff changeset
621 or with the escape sequence <tt>\<i>ddd</i></tt>,
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622 where <i>ddd</i> is a sequence of up to three decimal digits.
371
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623 (Note that if a decimal escape sequence is to be followed by a digit,
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624 it must be expressed using exactly three digits.)
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parents:
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625
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
626
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
627 <p>
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628 Literal strings can also be defined using a long format
380
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629 enclosed by <i>long brackets</i>.
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630 We define an <i>opening long bracket of level <i>n</i></i> as an opening
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631 square bracket followed by <i>n</i> equal signs followed by another
371
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632 opening square bracket.
380
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diff changeset
633 So, an opening long bracket of level 0 is written as <tt>[[</tt>,
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634 an opening long bracket of level 1 is written as <tt>[=[</tt>,
371
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635 and so on.
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636 A <i>closing long bracket</i> is defined similarly;
371
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637 for instance,
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638 a closing long bracket of level 4 is written as <tt>]====]</tt>.
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639 A <i>long literal</i> starts with an opening long bracket of any level and
371
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640 ends at the first closing long bracket of the same level.
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parents:
diff changeset
641 It can contain any text except a closing bracket of the same level.
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parents:
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642 Literals in this bracketed form can run for several lines,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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643 do not interpret any escape sequences,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
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644 and ignore long brackets of any other level.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
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645 Any kind of end-of-line sequence
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
646 (carriage return, newline, carriage return followed by newline,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
647 or newline followed by carriage return)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
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648 is converted to a simple newline.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
649
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
650
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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651 <p>
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diff changeset
652 Any character in a literal string not
371
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653 explicitly affected by the previous rules represents itself.
380
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diff changeset
654 However, Luan opens files for parsing in text mode,
371
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655 and the system file functions may have problems with
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
656 some control characters.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
657 So, it is safer to represent
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
658 non-text data as a quoted literal with
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
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659 explicit escape sequences for non-text characters.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
660
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
661
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
662 <p>
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parents:
diff changeset
663 For convenience,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
664 when the opening long bracket is immediately followed by a newline,
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665 the newline is not included in the string.
380
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diff changeset
666 As an example
371
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667 the five literal strings below denote the same string:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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668
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669 <p><tt><pre>
371
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670 a = 'alo\n123"'
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parents:
diff changeset
671 a = "alo\n123\""
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
672 a = '\97lo\10\04923"'
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
673 a = [[alo
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
674 123"]]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
675 a = [==[
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
676 alo
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diff changeset
677 123"]==]
389
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diff changeset
678 </pre></tt></p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
679
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parents:
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680 <p>
380
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diff changeset
681 A <i>numerical constant</i> (or <i>numeral</i>)
371
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682 can be written with an optional fractional part
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683 and an optional decimal exponent,
380
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684 marked by a letter '<tt>e</tt>' or '<tt>E</tt>'.
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685 Luan also accepts hexadecimal constants,
6c6c3537035e work on manual
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686 which start with <tt>0x</tt> or <tt>0X</tt>.
371
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687 Hexadecimal constants also accept an optional fractional part
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688 plus an optional binary exponent,
380
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689 marked by a letter '<tt>p</tt>' or '<tt>P</tt>'.
371
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690 A numeric constant with a fractional dot or an exponent
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
691 denotes a float;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
692 otherwise it denotes an integer.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
693 Examples of valid integer constants are
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
694
389
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diff changeset
695 <p><tt><pre>
371
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parents:
diff changeset
696 3 345 0xff 0xBEBADA
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diff changeset
697 </pre></tt></p>
382
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diff changeset
698
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diff changeset
699 <p>
371
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diff changeset
700 Examples of valid float constants are
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
701
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diff changeset
702 <p><tt><pre>
371
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parents:
diff changeset
703 3.0 3.1416 314.16e-2 0.31416E1 34e1
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
704 0x0.1E 0xA23p-4 0X1.921FB54442D18P+1
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diff changeset
705 </pre></tt></p>
371
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parents:
diff changeset
706
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
707 <p>
380
6c6c3537035e work on manual
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diff changeset
708 A <i>comment</i> starts with a double hyphen (<tt>--</tt>)
371
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709 anywhere outside a string.
380
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diff changeset
710 If the text immediately after <tt>--</tt> is not an opening long bracket,
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diff changeset
711 the comment is a <i>short comment</i>,
371
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712 which runs until the end of the line.
380
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diff changeset
713 Otherwise, it is a <i>long comment</i>,
371
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diff changeset
714 which runs until the corresponding closing long bracket.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
715 Long comments are frequently used to disable code temporarily.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
716
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
717
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
718
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
719
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
720
380
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diff changeset
721 <h3 margin-top="1em"><a name="vars">Variables</a></h3>
371
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diff changeset
722
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
723 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
724 Variables are places that store values.
380
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diff changeset
725 There are three kinds of variables in Luan:
371
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diff changeset
726 global variables, local variables, and table fields.
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parents:
diff changeset
727
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
728
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
729 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
730 A single name can denote a global variable or a local variable
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
731 (or a function's formal parameter,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
732 which is a particular kind of local variable):
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parents:
diff changeset
733
389
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diff changeset
734 <p><tt><pre>
371
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diff changeset
735 var ::= Name
389
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diff changeset
736 </pre></tt></p>
382
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diff changeset
737
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diff changeset
738 <p>
464
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diff changeset
739 Name denotes identifiers, as defined in <a href="#lex">Lexical Conventions</a>.
371
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diff changeset
740
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
741
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
742 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
743 Any variable name is assumed to be global unless explicitly declared
464
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parents: 429
diff changeset
744 as a local (see <a href="#local_stmt">Local Declarations</a>).
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diff changeset
745 Local variables are <i>lexically scoped</i>:
371
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diff changeset
746 local variables can be freely accessed by functions
464
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parents: 429
diff changeset
747 defined inside their scope (see <a href="#visibility">Visibility Rules</a>).
371
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diff changeset
748
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parents:
diff changeset
749
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
750 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
751 Before the first assignment to a variable, its value is <b>nil</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
752
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
753
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
754 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
755 Square brackets are used to index a table:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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756
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757 <p><tt><pre>
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758 var ::= prefixexp &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo;
389
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diff changeset
759 </pre></tt></p>
382
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diff changeset
760
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diff changeset
761 <p>
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762 The meaning of accesses to table fields can be changed via metatables.
380
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763 An access to an indexed variable <tt>t[i]</tt> is equivalent to
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764 a call <tt>gettable_event(t,i)</tt>.
464
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765 (See <a href="#meta">Metatables and Metamethods</a> for a complete description of the
380
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diff changeset
766 <tt>gettable_event</tt> function.
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767 This function is not defined or callable in Luan.
371
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768 We use it here only for explanatory purposes.)
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diff changeset
769
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parents:
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770
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771 <p>
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diff changeset
772 The syntax <tt>var.Name</tt> is just syntactic sugar for
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773 <tt>var["Name"]</tt>:
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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774
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775 <p><tt><pre>
371
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776 var ::= prefixexp &lsquo;<b>.</b>&rsquo; Name
389
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diff changeset
777 </pre></tt></p>
371
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parents:
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778
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779 <p>
380
6c6c3537035e work on manual
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diff changeset
780 An access to a global variable <tt>x</tt>
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781 is equivalent to <tt>_ENV.x</tt>.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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782 Due to the way that chunks are compiled,
464
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783 <tt>_ENV</tt> is never a global name (see <a href="#env">Environments</a>).
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
784
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parents:
diff changeset
785
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parents:
diff changeset
786
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
787
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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788
389
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diff changeset
789 <h3 margin-top="1em"><a name="stmts">Statements</a></h3>
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diff changeset
790
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791 <p>
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diff changeset
792 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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793 similar to those in Pascal or C.
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794 This set includes
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795 assignments, control structures, function calls,
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796 and variable declarations.
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797
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parents:
diff changeset
798
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
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799
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800 <h4 margin-top="1em"><a name="blocks">Blocks</a></h4>
371
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801
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802 <p>
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803 A block is a list of statements,
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804 which are executed sequentially:
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805
389
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806 <p><tt><pre>
371
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807 block ::= {stat}
389
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diff changeset
808 </pre></tt></p>
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diff changeset
809
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810 <p>
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diff changeset
811 Luan has <i>empty statements</i>
371
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812 that allow you to separate statements with semicolons,
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813 start a block with a semicolon
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814 or write two semicolons in sequence:
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815
389
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816 <p><tt><pre>
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817 stat ::= &lsquo;<b>;</b>&rsquo;
389
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diff changeset
818 </pre></tt></p>
371
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819
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820 <p>
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821 A block can be explicitly delimited to produce a single statement:
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822
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diff changeset
823 <p><tt><pre>
371
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824 stat ::= <b>do</b> block <b>end</b>
389
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825 </pre></tt></p>
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diff changeset
826
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diff changeset
827 <p>
371
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828 Explicit blocks are useful
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829 to control the scope of variable declarations.
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830 Explicit blocks are also sometimes used to
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831 add a <b>return</b> statement in the middle
464
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832 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
833
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parents:
diff changeset
834
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
835
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
836
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
837
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diff changeset
838 <h4 margin-top="1em"><a name="chunks">Chunks</a></h4>
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diff changeset
839
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840 <p>
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diff changeset
841 The unit of compilation of Luan is called a <i>chunk</i>.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
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842 Syntactically,
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parents:
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843 a chunk is simply a block:
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parents:
diff changeset
844
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diff changeset
845 <p><tt><pre>
371
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846 chunk ::= block
395
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parents: 391
diff changeset
847 </pre></tt></p>
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parents: 391
diff changeset
848
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diff changeset
849 <p>
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diff changeset
850 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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851 with a variable number of arguments
464
eddf7c73373b fix references in the manual
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diff changeset
852 (see <a href="#fn_def">Function Definitions</a>).
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
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853 As such, chunks can define local variables,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
854 receive arguments, and return values.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
855
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
856
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
857 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
858 A chunk can be stored in a file or in a string inside the host program.
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parents:
diff changeset
859 To execute a chunk,
395
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diff changeset
860 Luan first <i>loads</i> it,
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861 compiling the chunk's code,
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862 and then Luan executes the compiled code.
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diff changeset
863
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diff changeset
864
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parents: 391
diff changeset
865
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diff changeset
866
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diff changeset
867
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diff changeset
868 <h4 margin-top="1em"><a name="assignment">Assignment</a></h4>
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parents: 391
diff changeset
869
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870 <p>
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diff changeset
871 Luan allows multiple assignments.
371
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872 Therefore, the syntax for assignment
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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873 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:
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874 and a list of expressions on the right side.
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parents:
diff changeset
875 The elements in both lists are separated by commas:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
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876
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diff changeset
877 <p><tt><pre>
371
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parents:
diff changeset
878 stat ::= varlist &lsquo;<b>=</b>&rsquo; explist
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parents:
diff changeset
879 varlist ::= var {&lsquo;<b>,</b>&rsquo; var}
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parents:
diff changeset
880 explist ::= exp {&lsquo;<b>,</b>&rsquo; exp}
395
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diff changeset
881 </pre></tt></p>
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parents: 391
diff changeset
882
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diff changeset
883 <p>
464
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diff changeset
884 Expressions are discussed in <a href="#expressions">Expressions</a>.
371
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parents:
diff changeset
885
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parents:
diff changeset
886
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
887 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
888 Before the assignment,
395
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diff changeset
889 the list of values is <i>adjusted</i> to the length of
371
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diff changeset
890 the list of variables.
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parents:
diff changeset
891 If there are more values than needed,
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892 the excess values are thrown away.
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diff changeset
893 If there are fewer values than needed,
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parents:
diff changeset
894 the list is extended with as many <b>nil</b>'s as needed.
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diff changeset
895 If the list of expressions ends with a function call,
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896 then all values returned by that call enter the list of values,
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897 before the adjustment
464
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diff changeset
898 (except when the call is enclosed in parentheses; see <a href="#expressions">Expressions</a>).
371
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diff changeset
899
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
900
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
901 <p>
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parents:
diff changeset
902 The assignment statement first evaluates all its expressions
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parents:
diff changeset
903 and only then the assignments are performed.
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parents:
diff changeset
904 Thus the code
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diff changeset
905
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diff changeset
906 <p><tt><pre>
371
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diff changeset
907 i = 3
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diff changeset
908 i, a[i] = i+1, 20
395
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diff changeset
909 </pre></tt></p>
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diff changeset
910
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diff changeset
911 <p>
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diff changeset
912 sets <tt>a[3]</tt> to 20, without affecting <tt>a[4]</tt>
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913 because the <tt>i</tt> in <tt>a[i]</tt> is evaluated (to 3)
371
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914 before it is assigned&nbsp;4.
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diff changeset
915 Similarly, the line
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diff changeset
916
395
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917 <p><tt><pre>
371
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918 x, y = y, x
395
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diff changeset
919 </pre></tt></p>
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diff changeset
920
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diff changeset
921 <p>
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diff changeset
922 exchanges the values of <tt>x</tt> and <tt>y</tt>,
371
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diff changeset
923 and
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diff changeset
924
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diff changeset
925 <p><tt><pre>
371
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diff changeset
926 x, y, z = y, z, x
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diff changeset
927 </pre></tt></p>
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diff changeset
928
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diff changeset
929 <p>
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diff changeset
930 cyclically permutes the values of <tt>x</tt>, <tt>y</tt>, and <tt>z</tt>.
371
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diff changeset
931
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diff changeset
932
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933 <p>
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934 The meaning of assignments to global variables
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935 and table fields can be changed via metatables.
395
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936 An assignment to an indexed variable <tt>t[i] = val</tt> is equivalent to
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937 <tt>settable_event(t,i,val)</tt>.
464
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938 (See <a href="#meta">Metatables and Metamethods</a> for a complete description of the
395
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939 <tt>settable_event</tt> function.
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940 This function is not defined or callable in Luan.
371
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941 We use it here only for explanatory purposes.)
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942
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diff changeset
943
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944 <p>
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945 An assignment to a global name <tt>x = val</tt>
371
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946 is equivalent to the assignment
464
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947 <tt>_ENV.x = val</tt> (see <a href="#env">Environments</a>).
395
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948
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diff changeset
949
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diff changeset
950
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951
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952 <h4 margin-top="1em"><a name="control">Control Structures</a></h4>
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953
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954 <p>
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955 The control structures
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956 <b>if</b>, <b>while</b>, and <b>repeat</b> have the usual meaning and
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957 familiar syntax:
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958
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959 <p><tt><pre>
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960 stat ::= <b>while</b> exp <b>do</b> block <b>end</b>
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961 stat ::= <b>repeat</b> block <b>until</b> exp
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962 stat ::= <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] <b>end</b>
395
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963 </pre></tt></p>
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964
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965 <p>
464
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diff changeset
966 Luan also has a <b>for</b> statement (see <a href="#for">For Statement</a>).
371
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967
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diff changeset
968
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969 <p>
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970 The condition expression of a
395
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971 control structure must be a boolean.
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972 Any other value type will produce an error.
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diff changeset
973 This helps catch errors and makes code more readable.
371
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974
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parents:
diff changeset
975
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diff changeset
976 <p>
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977 In the <b>repeat</b>&ndash;<b>until</b> loop,
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978 the inner block does not end at the <b>until</b> keyword,
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979 but only after the condition.
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980 So, the condition can refer to local variables
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981 declared inside the loop block.
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982
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parents:
diff changeset
983
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diff changeset
984 <p>
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985 The <b>break</b> statement terminates the execution of a
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986 <b>while</b>, <b>repeat</b>, or <b>for</b> loop,
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987 skipping to the next statement after the loop:
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diff changeset
988
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diff changeset
989
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990 <p><tt><pre>
371
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991 stat ::= <b>break</b>
395
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diff changeset
992 </pre></tt></p>
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diff changeset
993
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diff changeset
994 <p>
371
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995 A <b>break</b> ends the innermost enclosing loop.
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diff changeset
996
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parents:
diff changeset
997
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parents:
diff changeset
998 <p>
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parents:
diff changeset
999 The <b>return</b> statement is used to return values
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diff changeset
1000 from a function or a chunk
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1001 (which is an anonymous function).
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parents:
diff changeset
1002
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diff changeset
1003 Functions can return more than one value,
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1004 so the syntax for the <b>return</b> statement is
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diff changeset
1005
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diff changeset
1006 <p><tt><pre>
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1007 stat ::= <b>return</b> [explist] [&lsquo;<b>;</b>&rsquo;]
395
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diff changeset
1008 </pre></tt></p>
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parents: 391
diff changeset
1009
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diff changeset
1010
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diff changeset
1011
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diff changeset
1012
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diff changeset
1013 <h4 margin-top="1em"><a name="for">For Statement</a></h4>
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diff changeset
1014
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diff changeset
1015 <p>
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diff changeset
1016 The <b>for</b> statement works over functions,
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diff changeset
1017 called <i>iterators</i>.
a7cb58532846 work on manual
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diff changeset
1018 On each iteration, the iterator function is called to produce a new value,
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diff changeset
1019 stopping when this new value is <b>nil</b>.
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diff changeset
1020 The <b>for</b> loop has the following syntax:
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1021
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diff changeset
1022 <p><tt><pre>
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diff changeset
1023 stat ::= <b>for</b> namelist <b>in</b> exp <b>do</b> block <b>end</b>
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diff changeset
1024 namelist ::= Name {&lsquo;<b>,</b>&rsquo; Name}
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diff changeset
1025 </pre></tt></p>
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diff changeset
1026
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diff changeset
1027 <p>
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diff changeset
1028 A <b>for</b> statement like
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diff changeset
1029
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diff changeset
1030 <p><tt><pre>
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diff changeset
1031 for <i>var_1</i>, &middot;&middot;&middot;, <i>var_n</i> in <i>exp</i> do <i>block</i> end
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diff changeset
1032 </pre></tt></p>
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diff changeset
1033
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diff changeset
1034 <p>
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1035 is equivalent to the code:
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1036
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diff changeset
1037 <p><tt><pre>
371
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1038 do
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diff changeset
1039 local <i>f</i> = <i>exp</i>
371
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1040 while true do
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1041 local <i>var_1</i>, &middot;&middot;&middot;, <i>var_n</i> = <i>f</i>()
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diff changeset
1042 if <i>var_1</i> == nil then break end
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diff changeset
1043 <i>block</i>
371
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1044 end
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diff changeset
1045 end
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diff changeset
1046 </pre></tt></p>
371
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diff changeset
1047
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parents:
diff changeset
1048 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1049 Note the following:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1050
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1051 <ul>
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parents:
diff changeset
1052
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1053 <li>
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1054 <tt><i>exp</i></tt> is evaluated only once.
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diff changeset
1055 Its result is an <i>iterator</i> function.
371
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1056 </li>
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parents:
diff changeset
1057
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1058 <li>
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diff changeset
1059 <tt><i>f</i></tt> is an invisible variable.
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diff changeset
1060 The name is here for explanatory purposes only.
371
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1061 </li>
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parents:
diff changeset
1062
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diff changeset
1063 <li>
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diff changeset
1064 You can use <b>break</b> to exit a <b>for</b> loop.
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diff changeset
1065 </li>
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diff changeset
1066
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diff changeset
1067 <li>
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1068 The loop variables <tt><i>var_i</i></tt> are local to the loop;
371
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1069 you cannot use their values after the <b>for</b> ends.
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diff changeset
1070 If you need these values,
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diff changeset
1071 then assign them to other variables before breaking or exiting the loop.
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1072 </li>
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diff changeset
1073
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diff changeset
1074 </ul>
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parents:
diff changeset
1075
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parents:
diff changeset
1076
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1077
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1078
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1079 <h4 margin-top="1em"><a name="fn_stmt">Function Calls as Statements</a></h4>
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1080
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diff changeset
1081 <p>
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1082 To allow possible side-effects,
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1083 function calls can be executed as statements:
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1084
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1085 <p><tt><pre>
371
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1086 stat ::= functioncall
395
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diff changeset
1087 </pre></tt></p>
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diff changeset
1088
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1089 <p>
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1090 In this case, all returned values are thrown away.
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1091 Function calls are explained in <a href="#fn_calls">Function Calls</a>.
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1092
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diff changeset
1093
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1094
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1095 <h4 margin-top="1em"><a name="local_stmt">Local Declarations</a></h4>
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diff changeset
1096
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diff changeset
1097 <p>
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1098 Local variables can be declared anywhere inside a block.
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1099 The declaration can include an initial assignment:
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1100
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1101 <p><tt><pre>
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1102 stat ::= <b>local</b> namelist [&lsquo;<b>=</b>&rsquo; explist]
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diff changeset
1103 </pre></tt></p>
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diff changeset
1104
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1105 <p>
371
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1106 If present, an initial assignment has the same semantics
464
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1107 of a multiple assignment (see <a href="#assignment">Assignment</a>).
371
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1108 Otherwise, all variables are initialized with <b>nil</b>.
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diff changeset
1109
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diff changeset
1110
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1111 <p>
464
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1112 A chunk is also a block (see <a href="#chunks">Chunks</a>),
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1113 and so local variables can be declared in a chunk outside any explicit block.
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1114
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1115
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1116 <p>
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1117 The visibility rules for local variables are explained in <a href="#visibility">Visibility Rules</a>.
371
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1118
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1119
465
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diff changeset
1120 <h4 margin-top="1em"><a name="template_stmt">Template Statements</a></h4>
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diff changeset
1121
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1122 <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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diff changeset
1123
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1124 <p><tt><pre><%=Html.encode[[
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diff changeset
1125 local name = "Bob"
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diff changeset
1126 %>
469
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diff changeset
1127 Hello <%= name %>!
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diff changeset
1128 Bye <%= name %>.
465
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diff changeset
1129 <%
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1130 ]]%></pre></tt></p>
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diff changeset
1131
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1132 <p>is equivalent to the code:</p>
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diff changeset
1133
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1134 <p><tt><pre><%=Html.encode[[
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diff changeset
1135 local name = "Bob"
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diff changeset
1136 require("luan:Io").stdout.write( %>
469
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parents: 468
diff changeset
1137 Hello <%= name %>!
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1138 Bye <%= name %>.
465
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diff changeset
1139 <% )
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diff changeset
1140 ]]%></pre></tt></p>
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diff changeset
1141
371
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1142
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1143
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1144 <h3 margin-top="1em"><a name="expressions">Expressions</a></h3>
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diff changeset
1145
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1146 <p>
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1147 The basic expressions in Luan are the following:
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diff changeset
1148
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1149 <p><tt><pre>
371
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1150 exp ::= prefixexp
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diff changeset
1151 exp ::= <b>nil</b> | <b>false</b> | <b>true</b>
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parents:
diff changeset
1152 exp ::= Numeral
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1153 exp ::= LiteralString
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parents:
diff changeset
1154 exp ::= functiondef
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parents:
diff changeset
1155 exp ::= tableconstructor
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1156 exp ::= &lsquo;<b>...</b>&rsquo;
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parents:
diff changeset
1157 exp ::= exp binop exp
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parents:
diff changeset
1158 exp ::= unop exp
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1159 prefixexp ::= var | functioncall | &lsquo;<b>(</b>&rsquo; exp &lsquo;<b>)</b>&rsquo;
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diff changeset
1160 </pre></tt></p>
371
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diff changeset
1161
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parents:
diff changeset
1162 <p>
464
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diff changeset
1163 Numerals and literal strings are explained in <a href="#lex">Lexical Conventions</a>;
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diff changeset
1164 variables are explained in <a href="#vars">Variables</a>;
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diff changeset
1165 function definitions are explained in <a href="#fn_def">Function Definitions</a>;
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diff changeset
1166 function calls are explained in <a href="#fn_calls">Function Calls</a>;
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diff changeset
1167 table constructors are explained in <a href="#constructors">Table Constructors</a>.
371
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1168 Vararg expressions,
395
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1169 denoted by three dots ('<tt>...</tt>'), can only be used when
371
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1170 directly inside a vararg function;
464
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diff changeset
1171 they are explained in <a href="#fn_def">Function Definitions</a>.
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diff changeset
1172
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diff changeset
1173
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diff changeset
1174 <p>
eddf7c73373b fix references in the manual
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diff changeset
1175 Binary operators comprise arithmetic operators (see <a href="#arithmetic">Arithmetic Operators</a>),
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diff changeset
1176 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
1177 and the concatenation operator (see <a href="#concatenation">Concatenation</a>).
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diff changeset
1178 Unary operators comprise the unary minus (see <a href="#arithmetic">Arithmetic Operators</a>),
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diff changeset
1179 the unary logical <b>not</b> (see <a href="#logical_ops">Logical Operators</a>),
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diff changeset
1180 and the unary <em>length operator</em> (see <a href="#length">The Length Operator</a>).
371
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1181
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parents:
diff changeset
1182
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1183 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1184 Both function calls and vararg expressions can result in multiple values.
464
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diff changeset
1185 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
1186 then its return list is adjusted to zero elements,
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diff changeset
1187 thus discarding all returned values.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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1188 If an expression is used as the last (or the only) element
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1189 of a list of expressions,
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diff changeset
1190 then no adjustment is made
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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1191 (unless the expression is enclosed in parentheses).
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1192 In all other contexts,
395
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1193 Luan adjusts the result list to one element,
371
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1194 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
1195 or adding a single <b>nil</b> if there are no values.
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diff changeset
1196
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diff changeset
1197
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diff changeset
1198 <p>
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parents:
diff changeset
1199 Here are some examples:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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1200
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1201 <p><tt><pre>
371
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diff changeset
1202 f() -- adjusted to 0 results
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diff changeset
1203 g(f(), x) -- f() is adjusted to 1 result
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diff changeset
1204 g(x, f()) -- g gets x plus all results from f()
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parents:
diff changeset
1205 a,b,c = f(), x -- f() is adjusted to 1 result (c gets nil)
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parents:
diff changeset
1206 a,b = ... -- a gets the first vararg parameter, b gets
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1207 -- the second (both a and b can get nil if there
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1208 -- is no corresponding vararg parameter)
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diff changeset
1209
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1210 a,b,c = x, f() -- f() is adjusted to 2 results
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parents:
diff changeset
1211 a,b,c = f() -- f() is adjusted to 3 results
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1212 return f() -- returns all results from f()
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1213 return ... -- returns all received vararg parameters
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1214 return x,y,f() -- returns x, y, and all results from f()
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parents:
diff changeset
1215 {f()} -- creates a list with all results from f()
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1216 {...} -- creates a list with all vararg parameters
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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1217 {f(), nil} -- f() is adjusted to 1 result
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diff changeset
1218 </pre></tt></p>
371
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1219
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1220 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1221 Any expression enclosed in parentheses always results in only one value.
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1222 Thus,
395
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diff changeset
1223 <tt>(f(x,y,z))</tt> is always a single value,
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1224 even if <tt>f</tt> returns several values.
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diff changeset
1225 (The value of <tt>(f(x,y,z))</tt> is the first value returned by <tt>f</tt>
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diff changeset
1226 or <b>nil</b> if <tt>f</tt> does not return any values.)
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diff changeset
1227
a7cb58532846 work on manual
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diff changeset
1228
a7cb58532846 work on manual
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diff changeset
1229
a7cb58532846 work on manual
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diff changeset
1230 <h4 margin-top="1em"><a name="arithmetic">Arithmetic Operators</a></h4>
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diff changeset
1231
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diff changeset
1232 <p>
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diff changeset
1233 Luan supports the following arithmetic operators:
371
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parents:
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1234
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1235 <ul>
395
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1236 <li><b><tt>+</tt>: </b>addition</li>
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1237 <li><b><tt>-</tt>: </b>subtraction</li>
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parents: 391
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1238 <li><b><tt>*</tt>: </b>multiplication</li>
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1239 <li><b><tt>/</tt>: </b>division</li>
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1240 <li><b><tt>%</tt>: </b>modulo</li>
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diff changeset
1241 <li><b><tt>^</tt>: </b>exponentiation</li>
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parents: 391
diff changeset
1242 <li><b><tt>-</tt>: </b>unary minus</li>
371
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parents:
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1243 </ul>
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parents:
diff changeset
1244
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1245 <p>
395
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diff changeset
1246 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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parents:
diff changeset
1247
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1248 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1249 Modulo is defined as the remainder of a division
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1250 that rounds the quotient towards minus infinite (floor division).
395
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diff changeset
1251 (The Java modulo operator is not used.)
371
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parents:
diff changeset
1252
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1253
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1254
396
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diff changeset
1255 <h4 margin-top="1em"><a name="conversions">Coercions and Conversions</a></h4>
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diff changeset
1256
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diff changeset
1257 <p>
465
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diff changeset
1258 Luan generally avoids automatic conversions.
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diff changeset
1259 String concatenation automatically converts all of its arguments to strings.
47c7de1f2322 documentation work
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parents: 464
diff changeset
1260
47c7de1f2322 documentation work
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parents: 464
diff changeset
1261 <p>
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parents: 464
diff changeset
1262 Luan provides library functions for explicit type conversions.
371
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1263
396
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diff changeset
1264
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diff changeset
1265
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diff changeset
1266
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diff changeset
1267 <h4 margin-top="1em"><a name="relational">Relational Operators</a></h4>
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diff changeset
1268
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diff changeset
1269 <p>
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diff changeset
1270 Luan supports the following relational operators:
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1271
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1272 <ul>
396
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1273 <li><b><tt>==</tt>: </b>equality</li>
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1274 <li><b><tt>~=</tt>: </b>inequality</li>
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1275 <li><b><tt>&lt;</tt>: </b>less than</li>
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1276 <li><b><tt>&gt;</tt>: </b>greater than</li>
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parents: 395
diff changeset
1277 <li><b><tt>&lt;=</tt>: </b>less or equal</li>
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diff changeset
1278 <li><b><tt>&gt;=</tt>: </b>greater or equal</li>
371
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parents:
diff changeset
1279 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1280 These operators always result in <b>false</b> or <b>true</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1281
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1282
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1283 <p>
396
ba8b0aae6453 work on manual;
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diff changeset
1284 Equality (<tt>==</tt>) first compares the type of its operands.
371
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parents:
diff changeset
1285 If the types are different, then the result is <b>false</b>.
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diff changeset
1286 Otherwise, the values of the operands are compared.
396
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1287 Strings, numbers, and binary values are compared in the obvious way (by value).
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parents: 395
diff changeset
1288
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1289 <p>
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parents: 395
diff changeset
1290 Tables
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1291 are compared by reference:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1292 two objects are considered equal only if they are the same object.
396
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1293 Every time you create a new table,
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1294 it is different from any previously existing table.
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1295 Closures are also compared by reference.
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1296
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diff changeset
1297 <p>
417
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parents: 396
diff changeset
1298 You can change the way that Luan compares tables
464
eddf7c73373b fix references in the manual
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parents: 429
diff changeset
1299 by using the "eq" metamethod (see <a href="#meta">Metatables and Metamethods</a>).
371
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1300
396
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diff changeset
1301 <p>
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parents: 395
diff changeset
1302 Userdata are Java objects. They 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)"><tt>equals</tt></a> method.
371
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parents:
diff changeset
1303
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Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1304 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1305 Equality comparisons do not convert strings to numbers
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1306 or vice versa.
396
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diff changeset
1307 Thus, <tt>"0"==0</tt> evaluates to <b>false</b>,
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parents: 395
diff changeset
1308 and <tt>t[0]</tt> and <tt>t["0"]</tt> denote different
371
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diff changeset
1309 entries in a table.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1310
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1311
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1312 <p>
396
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diff changeset
1313 The operator <tt>~=</tt> is exactly the negation of equality (<tt>==</tt>).
371
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diff changeset
1314
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Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1315
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1316 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1317 The order operators work as follows.
396
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diff changeset
1318
371
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diff changeset
1319 If both arguments are numbers,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1320 then they are compared following
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1321 the usual rule for binary operations.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1322 Otherwise, if both arguments are strings,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1323 then their values are compared according to the current locale.
396
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diff changeset
1324 Otherwise, Luan tries to call the "lt" or the "le"
464
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diff changeset
1325 metamethod (see <a href="#meta">Metatables and Metamethods</a>).
396
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diff changeset
1326 A comparison <tt>a &gt; b</tt> is translated to <tt>b &lt; a</tt>
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parents: 395
diff changeset
1327 and <tt>a &gt;= b</tt> is translated to <tt>b &lt;= a</tt>.
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diff changeset
1328
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diff changeset
1329
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diff changeset
1330
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diff changeset
1331
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diff changeset
1332
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diff changeset
1333 <h4 margin-top="1em"><a name="logical_ops">Logical Operators</a></h4>
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1334
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diff changeset
1335 <p>
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diff changeset
1336 The logical operators in Luan are
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1337 <b>and</b>, <b>or</b>, and <b>not</b>.
396
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diff changeset
1338 The <b>and</b> and <b>or</b> operators consider both <b>false</b> and <b>nil</b> as false
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1339 and anything else as true.
464
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diff changeset
1340 Like the control structures (see <a href="#control">Control Structures</a>),
396
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diff changeset
1341 the <b>not</b> operator requires a boolean value.
371
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diff changeset
1342
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parents:
diff changeset
1343 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1344 The negation operator <b>not</b> always returns <b>false</b> or <b>true</b>.
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parents:
diff changeset
1345 The conjunction operator <b>and</b> returns its first argument
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1346 if this value is <b>false</b> or <b>nil</b>;
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diff changeset
1347 otherwise, <b>and</b> returns its second argument.
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parents:
diff changeset
1348 The disjunction operator <b>or</b> returns its first argument
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parents:
diff changeset
1349 if this value is different from <b>nil</b> and <b>false</b>;
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diff changeset
1350 otherwise, <b>or</b> returns its second argument.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1351 Both <b>and</b> and <b>or</b> use short-circuit evaluation;
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diff changeset
1352 that is,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1353 the second operand is evaluated only if necessary.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1354 Here are some examples:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1355
396
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1356 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1357 10 or 20 --&gt; 10
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1358 10 or error() --&gt; 10
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1359 nil or "a" --&gt; "a"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1360 nil and 10 --&gt; nil
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1361 false and error() --&gt; false
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1362 false and nil --&gt; false
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1363 false or nil --&gt; nil
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1364 10 and 20 --&gt; 20
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1365 </pre></tt></p>
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1366
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1367 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1368 (In this manual,
396
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1369 <tt>--&gt;</tt> indicates the result of the preceding expression.)
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1370
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1371
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1372
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1373 <h4 margin-top="1em"><a name="concatenation">Concatenation</a></h4>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1374
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1375 <p>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1376 The string concatenation operator in Luan is
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1377 denoted by two dots ('<tt>..</tt>').
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1378 All operands are converted to strings.
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1379
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1380
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1381
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1382 <h4 margin-top="1em"><a name="length">The Length Operator</a></h4>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1383
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1384 <p>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1385 The length operator is denoted by the unary prefix operator <tt>#</tt>.
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1386 The length of a string is its number of characters.
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1387 The length of a binary is its number of bytes.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1388
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1389
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1390 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1391 A program can modify the behavior of the length operator for
464
eddf7c73373b fix references in the manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 429
diff changeset
1392 any table through the <tt>__len</tt> metamethod (see <a href="#meta">Metatables and Metamethods</a>).
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1393
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1394
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1395 <p>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1396 Unless a <tt>__len</tt> metamethod is given,
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1397 the length of a table <tt>t</tt> is defined
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1398 as the number of elements in <em>sequence</em>,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1399 that is,
396
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1400 the size of the set of its positive numeric keys is equal to <em>{1..n}</em>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1401 for some non-negative integer <em>n</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1402 In that case, <em>n</em> is its length.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1403 Note that a table like
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1404
396
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1405 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1406 {10, 20, nil, 40}
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1407 </pre></tt></p>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1408
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1409 <p>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1410 has a length of <tt>2</tt>, because that is the last key in sequence.
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1411
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1412
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1413
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1414
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1415
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1416 <h4 margin-top="1em"><a name="precedence">Precedence</a></h4>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1417
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1418 <p>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1419 Operator precedence in Luan follows the table below,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1420 from lower to higher priority:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1421
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1422 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1423 or
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1424 and
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1425 &lt; &gt; &lt;= &gt;= ~= ==
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1426 ..
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1427 + -
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1428 * / %
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1429 unary operators (not # -)
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1430 ^
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1431 </pre></tt></p>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1432
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1433 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1434 As usual,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1435 you can use parentheses to change the precedences of an expression.
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1436 The concatenation ('<tt>..</tt>') and exponentiation ('<tt>^</tt>')
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1437 operators are right associative.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1438 All other binary operators are left associative.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1439
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1440
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1441
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1442
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1443
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1444 <h4 margin-top="1em"><a name="constructors">Table Constructors</a></h4>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1445
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1446 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1447 Table constructors are expressions that create tables.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1448 Every time a constructor is evaluated, a new table is created.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1449 A constructor can be used to create an empty table
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1450 or to create a table and initialize some of its fields.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1451 The general syntax for constructors is
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1452
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1453 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1454 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
1455 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
1456 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
1457 fieldsep ::= &lsquo;<b>,</b>&rsquo; | &lsquo;<b>;</b>&rsquo;
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1458 </pre></tt></p>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1459
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1460 <p>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1461 Each field of the form <tt>[exp1] = exp2</tt> adds to the new table an entry
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1462 with key <tt>exp1</tt> and value <tt>exp2</tt>.
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1463 A field of the form <tt>name = exp</tt> is equivalent to
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1464 <tt>["name"] = exp</tt>.
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1465 Finally, fields of the form <tt>exp</tt> are equivalent to
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1466 <tt>[i] = exp</tt>, where <tt>i</tt> are consecutive integers
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1467 starting with 1.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1468 Fields in the other formats do not affect this counting.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1469 For example,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1470
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1471 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1472 a = { [f(1)] = g; "x", "y"; x = 1, f(x), [30] = 23; 45 }
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1473 </pre></tt></p>
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1474
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1475 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1476 is equivalent to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1477
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1478 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1479 do
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1480 local t = {}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1481 t[f(1)] = g
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1482 t[1] = "x" -- 1st exp
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1483 t[2] = "y" -- 2nd exp
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1484 t.x = 1 -- t["x"] = 1
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1485 t[3] = f(x) -- 3rd exp
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1486 t[30] = 23
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1487 t[4] = 45 -- 4th exp
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1488 a = t
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1489 end
396
ba8b0aae6453 work on manual;
Franklin Schmidt <fschmidt@gmail.com>
parents: 395
diff changeset
1490 </pre></tt></p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1491
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1492 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1493 The order of the assignments in a constructor is undefined.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1494 (This order would be relevant only when there are repeated keys.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1495
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1496
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1497 <p>
396
ba8b0aae6453 work on manual;
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parents: 395
diff changeset
1498 If the last field in the list has the form <tt>exp</tt>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1499 and the expression is a function call or a vararg expression,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1500 then all values returned by this expression enter the list consecutively
464
eddf7c73373b fix references in the manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 429
diff changeset
1501 (see <a href="#fn_calls">Function Calls</a>).
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
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 The field list can have an optional trailing separator,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1506 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
1507
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1508
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1509
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1510
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1511
417
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diff changeset
1512 <h4 margin-top="1em"><a name="fn_calls">Function Calls</a></h4>
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diff changeset
1513
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diff changeset
1514 <p>
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diff changeset
1515 A function call in Luan has the following syntax:
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diff changeset
1516
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diff changeset
1517 <p><tt><pre>
371
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diff changeset
1518 functioncall ::= prefixexp args
417
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diff changeset
1519 </pre></tt></p>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1520
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diff changeset
1521 <p>
371
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diff changeset
1522 In a function call,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1523 first prefixexp and args are evaluated.
417
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diff changeset
1524 If the value of prefixexp has type <i>function</i>,
371
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parents:
diff changeset
1525 then this function is called
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1526 with the given arguments.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1527 Otherwise, the prefixexp "call" metamethod is called,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1528 having as first parameter the value of prefixexp,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1529 followed by the original call arguments
464
eddf7c73373b fix references in the manual
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parents: 429
diff changeset
1530 (see <a href="#meta">Metatables and Metamethods</a>).
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1531
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1532
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1533 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1534 Arguments have the following syntax:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
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1535
417
a40e99cf0b0b work on manual
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diff changeset
1536 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1537 args ::= &lsquo;<b>(</b>&rsquo; [explist] &lsquo;<b>)</b>&rsquo;
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parents:
diff changeset
1538 args ::= tableconstructor
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1539 args ::= LiteralString
417
a40e99cf0b0b work on manual
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diff changeset
1540 </pre></tt></p>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1541
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diff changeset
1542 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1543 All argument expressions are evaluated before the call.
417
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diff changeset
1544 A call of the form <tt>f{<i>fields</i>}</tt> is
a40e99cf0b0b work on manual
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diff changeset
1545 syntactic sugar for <tt>f({<i>fields</i>})</tt>;
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1546 that is, the argument list is a single new table.
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1547 A call of the form <tt>f'<i>string</i>'</tt>
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diff changeset
1548 (or <tt>f"<i>string</i>"</tt> or <tt>f[[<i>string</i>]]</tt>)
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1549 is syntactic sugar for <tt>f('<i>string</i>')</tt>;
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1550 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
1551
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1552
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1553 <p>
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1554 A call of the form <tt>return <i>functioncall</i></tt> is called
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1555 a <i>tail call</i>.
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1556 Luan implements <i>proper tail calls</i>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1557 (or <i>proper tail recursion</i>):
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1558 in a tail call,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1559 the called function reuses the stack entry of the calling function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1560 Therefore, there is no limit on the number of nested tail calls that
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1561 a program can execute.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1562 However, a tail call erases any debug information about the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1563 calling function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1564 Note that a tail call only happens with a particular syntax,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1565 where the <b>return</b> has one single function call as argument;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1566 this syntax makes the calling function return exactly
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1567 the returns of the called function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1568 So, none of the following examples are tail calls:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1569
417
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parents: 396
diff changeset
1570 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1571 return (f(x)) -- results adjusted to 1
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1572 return 2 * f(x)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1573 return x, f(x) -- additional results
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1574 f(x); return -- results discarded
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1575 return x or f(x) -- results adjusted to 1
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1576 </pre></tt></p>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1577
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1578
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1579
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1580
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1581 <h4 margin-top="1em"><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
1582
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1583 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1584 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
1585
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1586 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1587 functiondef ::= <b>function</b> funcbody
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1588 funcbody ::= &lsquo;<b>(</b>&rsquo; [parlist] &lsquo;<b>)</b>&rsquo; block <b>end</b>
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1589 </pre></tt></p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1590
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1591 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1592 The following syntactic sugar simplifies function definitions:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1593
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1594 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1595 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
1596 stat ::= <b>local</b> <b>function</b> Name funcbody
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1597 funcname ::= Name {&lsquo;<b>.</b>&rsquo; Name} [&lsquo;<b>:</b>&rsquo; Name]
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1598 </pre></tt></p>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1599
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1600 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1601 The statement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1602
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1603 <p><tt><pre>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1604 function f () <i>body</i> end
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1605 </pre></tt></p>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1606
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1607 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1608 translates to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1609
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1610 <p><tt><pre>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1611 f = function () <i>body</i> end
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1612 </pre></tt></p>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1613
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1614 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1615 The statement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1616
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1617 <p><tt><pre>
a40e99cf0b0b work on manual
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diff changeset
1618 function t.a.b.c.f () <i>body</i> end
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1619 </pre></tt></p>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1620
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1621 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1622 translates to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1623
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1624 <p><tt><pre>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1625 t.a.b.c.f = function () <i>body</i> end
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1626 </pre></tt></p>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1627
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1628 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1629 The statement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1630
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1631 <p><tt><pre>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1632 local function f () <i>body</i> end
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1633 </pre></tt></p>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1634
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1635 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1636 translates to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1637
417
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1638 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1639 local f; f = function () <em>body</em> end
417
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1640 </pre></tt></p>
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1641
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1642 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1643 not to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1644
417
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1645 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1646 local f = function () <em>body</em> end
417
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1647 </pre></tt></p>
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1648
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1649 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1650 (This only makes a difference when the body of the function
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1651 contains references to <tt>f</tt>.)
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1652
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1653
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1654 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1655 A function definition is an executable expression,
417
a40e99cf0b0b work on manual
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diff changeset
1656 whose value has type <i>function</i>.
a40e99cf0b0b work on manual
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diff changeset
1657 When Luan precompiles a chunk,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1658 all its function bodies are precompiled too.
417
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diff changeset
1659 Then, whenever Luan executes the function definition,
a40e99cf0b0b work on manual
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diff changeset
1660 the function is <i>instantiated</i> (or <i>closed</i>).
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diff changeset
1661 This function instance (or <i>closure</i>)
371
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parents:
diff changeset
1662 is the final value of the expression.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1663
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1664
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1665 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1666 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
1667 initialized with the argument values:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1668
417
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diff changeset
1669 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
1670 parlist ::= namelist [&lsquo;<b>,</b>&rsquo; &lsquo;<b>...</b>&rsquo;] | &lsquo;<b>...</b>&rsquo;
417
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diff changeset
1671 </pre></tt></p>
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parents: 396
diff changeset
1672
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diff changeset
1673 <p>
371
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diff changeset
1674 When a function is called,
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parents:
diff changeset
1675 the list of arguments is adjusted to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1676 the length of the list of parameters,
417
a40e99cf0b0b work on manual
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diff changeset
1677 unless the function is a <i>vararg function</i>,
a40e99cf0b0b work on manual
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diff changeset
1678 which is indicated by three dots ('<tt>...</tt>')
371
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diff changeset
1679 at the end of its parameter list.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1680 A vararg function does not adjust its argument list;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1681 instead, it collects all extra arguments and supplies them
417
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diff changeset
1682 to the function through a <i>vararg expression</i>,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1683 which is also written as three dots.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1684 The value of this expression is a list of all actual extra arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1685 similar to a function with multiple results.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1686 If a vararg expression is used inside another expression
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1687 or in the middle of a list of expressions,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1688 then its return list is adjusted to one element.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1689 If the expression is used as the last element of a list of expressions,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1690 then no adjustment is made
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1691 (unless that last expression is enclosed in parentheses).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1692
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1693
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1694 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1695 As an example, consider the following definitions:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1696
417
a40e99cf0b0b work on manual
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diff changeset
1697 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1698 function f(a, b) end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1699 function g(a, b, ...) end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1700 function r() return 1,2,3 end
417
a40e99cf0b0b work on manual
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diff changeset
1701 </pre></tt></p>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1702
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diff changeset
1703 <p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1704 Then, we have the following mapping from arguments to parameters and
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1705 to the vararg expression:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1706
417
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diff changeset
1707 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1708 CALL PARAMETERS
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parents:
diff changeset
1709
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1710 f(3) a=3, b=nil
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1711 f(3, 4) a=3, b=4
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1712 f(3, 4, 5) a=3, b=4
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1713 f(r(), 10) a=1, b=10
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1714 f(r()) a=1, b=2
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1715
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1716 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
1717 g(3, 4) a=3, b=4, ... --&gt; (nothing)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1718 g(3, 4, 5, 8) a=3, b=4, ... --&gt; 5 8
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1719 g(5, r()) a=5, b=1, ... --&gt; 2 3
417
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parents: 396
diff changeset
1720 </pre></tt></p>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1721
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1722 <p>
464
eddf7c73373b fix references in the manual
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parents: 429
diff changeset
1723 Results are returned using the <b>return</b> statement (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
1724 If control reaches the end of a function
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1725 without encountering a <b>return</b> statement,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1726 then the function returns with no results.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1727
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1728
465
47c7de1f2322 documentation work
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parents: 464
diff changeset
1729 <h4 margin-top="1em"><a name="template_expr">Template Expressions</a></h4>
47c7de1f2322 documentation work
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parents: 464
diff changeset
1730
47c7de1f2322 documentation work
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parents: 464
diff changeset
1731 <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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parents: 464
diff changeset
1732
47c7de1f2322 documentation work
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parents: 464
diff changeset
1733 <p><tt><pre><%=Html.encode[[
47c7de1f2322 documentation work
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parents: 464
diff changeset
1734 local name = "Bob"
469
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parents: 468
diff changeset
1735 write( %>Hello <%= name %>!<% )
465
47c7de1f2322 documentation work
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parents: 464
diff changeset
1736 ]]%></pre></tt></p>
47c7de1f2322 documentation work
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parents: 464
diff changeset
1737
47c7de1f2322 documentation work
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parents: 464
diff changeset
1738 <p>This is equivalent to the code:</p>
47c7de1f2322 documentation work
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parents: 464
diff changeset
1739
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
1740 <p><tt><pre>
47c7de1f2322 documentation work
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parents: 464
diff changeset
1741 local name = "Bob"
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
1742 write( "Hello ", name, "!" )
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
1743 </pre></tt></p>
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
1744
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
1745 <p>The strings in template expressions may be multiple lines.</p>
47c7de1f2322 documentation work
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parents: 464
diff changeset
1746
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1747
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1748
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1749 <h3 margin-top="1em"><a name="visibility">Visibility Rules</a></h3>
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parents: 396
diff changeset
1750
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1751 <p>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1752 Luan is a lexically scoped language.
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1753 The scope of a local variable begins at the first statement after
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1754 its declaration and lasts until the last non-void statement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1755 of the innermost block that includes the declaration.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1756 Consider the following example:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1757
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1758 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1759 x = 10 -- global variable
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1760 do -- new block
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1761 local x = x -- new 'x', with value 10
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1762 print(x) --&gt; 10
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1763 x = x+1
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1764 do -- another block
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1765 local x = x+1 -- another 'x'
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1766 print(x) --&gt; 12
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1767 end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1768 print(x) --&gt; 11
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1769 end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1770 print(x) --&gt; 10 (the global one)
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1771 </pre></tt></p>
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1772
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1773 <p>
a40e99cf0b0b work on manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 396
diff changeset
1774 Notice that, in a declaration like <tt>local x = x</tt>,
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1775 the new <tt>x</tt> being declared is not in scope yet,
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1776 and so the second <tt>x</tt> 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
1777
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1778
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1779 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1780 Because of the lexical scoping rules,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1781 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
1782 defined inside their scope.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1783 A local variable used by an inner function is called
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1784 an <i>upvalue</i>, or <i>external local variable</i>,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1785 inside the inner function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1786
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1787
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1788 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1789 Notice that each execution of a <b>local</b> statement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1790 defines new local variables.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1791 Consider the following example:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1792
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1793 <p><tt><pre>
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1794 a = {}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1795 local x = 20
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1796 for i=1,10 do
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1797 local y = 0
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1798 a[i] = function () y=y+1; return x+y end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1799 end
417
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1800 </pre></tt></p>
a40e99cf0b0b work on manual
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parents: 396
diff changeset
1801
a40e99cf0b0b work on manual
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diff changeset
1802 <p>
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1803 The loop creates ten closures
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1804 (that is, ten instances of the anonymous function).
417
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diff changeset
1805 Each of these closures uses a different <tt>y</tt> variable,
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diff changeset
1806 while all of them share the same <tt>x</tt>.
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1807
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1808
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1809
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1810
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1811
468
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1812 <h2 margin-top="1em"><a name="libs">Standard Libraries</a></h2>
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diff changeset
1813
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diff changeset
1814 <p>
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diff changeset
1815 The standard Luan libraries provide useful functions
9b51e2413cab documentation
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1816 that are implemented both in Java and in Luan itself.
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1817 How each function is implemented shouldn't matter to the user.
371
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1818 Some of these functions provide essential services to the language
468
9b51e2413cab documentation
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diff changeset
1819 (e.g., <a href="#pdf-type"><tt>type</tt></a> and <a href="#pdf-getmetatable"><tt>get_metatable</tt></a>);
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diff changeset
1820 others provide access to "outside" services (e.g., I/O).
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1821
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1822
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1823 <h3 margin-top="1em"><a name="default_lib">Default Environment</a></h3>
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1824
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1825 <p>
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1826 These are provided by default as local variables for any Luan code as described in <a href="#env">Environments</a>.
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1827
470
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1828
468
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1829 <h4 margin-top="1em"><a name="_ENV"><tt>_ENV</tt></a></h4>
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diff changeset
1830
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1831 <p>
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1832 This is a table that holds the global variables of a module as described in <a href="#env">Environments</a>.
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1833
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1834
470
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diff changeset
1835 <h4 margin-top="1em"><a name="require"><tt>java ()</tt></a></h4>
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1836
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1837 <p>
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1838 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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1839
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1840
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1841 <h4 margin-top="1em"><a name="require"><tt>require (mod_uri)</tt></a></h4>
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1842
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1843 <p>
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1844 Example use:
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1845
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1846 <p><tt><pre>
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1847 local Table = require "luan:Table"
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1848 </pre></tt></p>
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1849
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1850 <p>
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1851 Could be defined as:
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1852
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1853 <p><tt><pre>
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1854 local function require(mod_name)
5627eb637eb4 documentation
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1855 return Package.load(mod_name) or Luan.error("module '"..mod_name.."' not found")
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1856 end
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diff changeset
1857 </pre></tt></p>
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diff changeset
1858
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1859
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1860 <h3 margin-top="1em"><a name="luan_lib">Basic Functions</a></h3>
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1861
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1862 <p>
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diff changeset
1863 Include this library by:
5627eb637eb4 documentation
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diff changeset
1864
5627eb637eb4 documentation
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diff changeset
1865 <p><tt><pre>
5627eb637eb4 documentation
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diff changeset
1866 local Luan = require "luan:Luan"
5627eb637eb4 documentation
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diff changeset
1867 </pre></tt></p>
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diff changeset
1868
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1869 The basic library provides basic functions to Luan that don't depend on other libaries.
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1870
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1871
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1872 <h4 margin-top="1em"><a name="Luan.assert"><tt>Luan.assert (v [, message])</tt></a></h4>
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diff changeset
1873
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1874 <p>
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1875 Could be defined as:
5627eb637eb4 documentation
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diff changeset
1876
5627eb637eb4 documentation
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1877 <p><tt><pre>
5627eb637eb4 documentation
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diff changeset
1878 function Luan.assert(v,message)
5627eb637eb4 documentation
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diff changeset
1879 return v or Luan.error(message or "assertion failed!")
5627eb637eb4 documentation
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1880 end
5627eb637eb4 documentation
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diff changeset
1881 </pre></tt></p>
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diff changeset
1882
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diff changeset
1883
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diff changeset
1884 <h4 margin-top="1em"><a name="Luan.assert_binary"><tt>Luan.assert_binary (v)</tt></a></h4>
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diff changeset
1885
5627eb637eb4 documentation
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diff changeset
1886 <p>
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diff changeset
1887 Could be defined as:
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diff changeset
1888
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diff changeset
1889 <p><tt><pre>
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diff changeset
1890 function Luan.assert_binary(v)
5627eb637eb4 documentation
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diff changeset
1891 local v_type = Luan.type(v)
5627eb637eb4 documentation
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diff changeset
1892 return v_type == "binary" and v or Luan.error("bad argument #1 (binary expected, got "..v_type..")")
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diff changeset
1893 end
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diff changeset
1894 </pre></tt></p>
5627eb637eb4 documentation
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diff changeset
1895
5627eb637eb4 documentation
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diff changeset
1896
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diff changeset
1897 <h4 margin-top="1em"><a name="Luan.assert_boolean"><tt>Luan.assert_boolean (v)</tt></a></h4>
5627eb637eb4 documentation
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diff changeset
1898
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diff changeset
1899 <p>
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diff changeset
1900 Like <a href="#Luan.assert_binary"><tt>assert_binary</tt></a> but for type <tt>boolean</tt>.
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diff changeset
1901
5627eb637eb4 documentation
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diff changeset
1902
5627eb637eb4 documentation
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diff changeset
1903 <h4 margin-top="1em"><a name="Luan.assert_integer"><tt>Luan.assert_integer (v)</tt></a></h4>
5627eb637eb4 documentation
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diff changeset
1904
5627eb637eb4 documentation
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diff changeset
1905 <p>
5627eb637eb4 documentation
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parents: 469
diff changeset
1906 Asserts that <tt>v</tt> can be converted to Java type <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Integer.html">Integer</a> and returns an Integer.
5627eb637eb4 documentation
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diff changeset
1907
5627eb637eb4 documentation
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diff changeset
1908
5627eb637eb4 documentation
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diff changeset
1909 <h4 margin-top="1em"><a name="Luan.assert_long"><tt>Luan.assert_long (v)</tt></a></h4>
5627eb637eb4 documentation
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diff changeset
1910
5627eb637eb4 documentation
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diff changeset
1911 <p>
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diff changeset
1912 Asserts that <tt>v</tt> can be converted to Java type <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Long.html">Long</a> and returns a Long.
5627eb637eb4 documentation
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diff changeset
1913
5627eb637eb4 documentation
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diff changeset
1914
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diff changeset
1915 <h4 margin-top="1em"><a name="Luan.assert_number"><tt>Luan.assert_number (v)</tt></a></h4>
5627eb637eb4 documentation
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parents: 469
diff changeset
1916
5627eb637eb4 documentation
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diff changeset
1917 <p>
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diff changeset
1918 Like <a href="#Luan.assert_binary"><tt>assert_binary</tt></a> but for type <tt>number</tt>.
5627eb637eb4 documentation
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parents: 469
diff changeset
1919
5627eb637eb4 documentation
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diff changeset
1920
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diff changeset
1921 <h4 margin-top="1em"><a name="Luan.assert_string"><tt>Luan.assert_string (v)</tt></a></h4>
5627eb637eb4 documentation
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diff changeset
1922
5627eb637eb4 documentation
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diff changeset
1923 <p>
5627eb637eb4 documentation
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parents: 469
diff changeset
1924 Like <a href="#Luan.assert_binary"><tt>assert_binary</tt></a> but for type <tt>string</tt>.
5627eb637eb4 documentation
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diff changeset
1925
5627eb637eb4 documentation
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parents: 469
diff changeset
1926
5627eb637eb4 documentation
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diff changeset
1927 <h4 margin-top="1em"><a name="Luan.assert_table"><tt>Luan.assert_table (v)</tt></a></h4>
5627eb637eb4 documentation
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diff changeset
1928
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diff changeset
1929 <p>
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diff changeset
1930 Like <a href="#Luan.assert_binary"><tt>assert_binary</tt></a> but for type <tt>table</tt>.
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diff changeset
1931
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diff changeset
1932
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diff changeset
1933 <h4 margin-top="1em"><a name="Luan.do_file"><tt>Luan.do_file ([uri])</tt></a></h4>
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diff changeset
1934
5627eb637eb4 documentation
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diff changeset
1935 <p>
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diff changeset
1936 Could be defined as:
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parents: 469
diff changeset
1937
5627eb637eb4 documentation
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diff changeset
1938 <p><tt><pre>
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parents: 469
diff changeset
1939 function Luan.do_file(uri)
5627eb637eb4 documentation
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diff changeset
1940 return load_file(uri)()
5627eb637eb4 documentation
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diff changeset
1941 end
5627eb637eb4 documentation
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parents: 469
diff changeset
1942 </pre></tt></p>
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parents: 469
diff changeset
1943
5627eb637eb4 documentation
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parents: 469
diff changeset
1944
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diff changeset
1945
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diff changeset
1946 <h4 margin-top="1em"><a name="Luan.error"><tt>Luan.error (message)</tt></a></h4>
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parents: 469
diff changeset
1947
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diff changeset
1948 <p>
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diff changeset
1949 Throws an error containing the message. This uses Java exceptions internally and the implementation is likely to change. So this documentation is likely to change.
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diff changeset
1950
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diff changeset
1951
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diff changeset
1952 <h4 margin-top="1em"><a name="Luan.get_metatable"><tt>Luan.get_metatable (table)</tt></a></h4>
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diff changeset
1953
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diff changeset
1954 <p>
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diff changeset
1955 If <tt>table</tt> does not have a metatable, returns <b>nil</b>.
371
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parents:
diff changeset
1956 Otherwise,
470
5627eb637eb4 documentation
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parents: 469
diff changeset
1957 if the table's metatable has a <tt>"__metatable"</tt> field,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
1958 returns the associated value.
470
5627eb637eb4 documentation
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parents: 469
diff changeset
1959 Otherwise, returns the metatable of the given table.
371
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parents:
diff changeset
1960
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parents:
diff changeset
1961
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parents:
diff changeset
1962
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parents:
diff changeset
1963
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parents:
diff changeset
1964 <p>
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parents:
diff changeset
1965 <hr><h3><a name="pdf-ipairs"><code>ipairs (t)</code></a></h3>
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parents:
diff changeset
1966
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parents:
diff changeset
1967
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parents:
diff changeset
1968 <p>
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parents:
diff changeset
1969 Returns three values (an iterator function, the table <code>t</code>, and 0)
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parents:
diff changeset
1970 so that the construction
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Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1971
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1972 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1973 for i,v in ipairs(t) 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
1974 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1975 will iterate over the key&ndash;value pairs
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1976 (<code>1,t[1]</code>), (<code>2,t[2]</code>), ...,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1977 up to the first nil value.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1978
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1979
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1980
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1981
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1982 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1983 <hr><h3><a name="pdf-load"><code>load (chunk [, chunkname [, mode [, env]]])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1984
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1985
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1986 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1987 Loads a chunk.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1988
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1989
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1990 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1991 If <code>chunk</code> is a string, the chunk is this string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1992 If <code>chunk</code> is a function,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1993 <code>load</code> calls it repeatedly to get the chunk pieces.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1994 Each call to <code>chunk</code> must return a string that concatenates
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1995 with previous results.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1996 A return of an empty string, <b>nil</b>, or no value signals the end of the chunk.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1997
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1998
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
1999 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2000 If there are no syntactic errors,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2001 returns the compiled chunk as a function;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2002 otherwise, returns <b>nil</b> plus the error message.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2003
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2004
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2005 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2006 If the resulting function has upvalues,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2007 the first upvalue is set to the value of <code>env</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2008 if that parameter is given,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2009 or to the value of the global environment.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2010 Other upvalues are initialized with <b>nil</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2011 (When you load a main chunk,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2012 the resulting function will always have exactly one upvalue,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2013 the <code>_ENV</code> variable (see <a href="#2.2">&sect;2.2</a>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2014 However,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2015 when you load a binary chunk created from a function (see <a href="#pdf-string.dump"><code>string.dump</code></a>),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2016 the resulting function can have an arbitrary number of upvalues.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2017 All upvalues are fresh, that is,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2018 they are not shared with any other function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2019
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2020
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2021 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2022 <code>chunkname</code> is used as the name of the chunk for error messages
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2023 and debug information (see <a href="#4.9">&sect;4.9</a>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2024 When absent,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2025 it defaults to <code>chunk</code>, if <code>chunk</code> is a string,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2026 or to "<code>=(load)</code>" otherwise.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2027
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2028
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2029 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2030 The string <code>mode</code> controls whether the chunk can be text or binary
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2031 (that is, a precompiled chunk).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2032 It may be the string "<code>b</code>" (only binary chunks),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2033 "<code>t</code>" (only text chunks),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2034 or "<code>bt</code>" (both binary and text).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2035 The default is "<code>bt</code>".
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2036
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2037
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2038 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2039 Lua does not check the consistency of binary chunks.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2040 Maliciously crafted binary chunks can crash
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2041 the interpreter.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2042
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2043
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2044
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2045
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2046 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2047 <hr><h3><a name="pdf-loadfile"><code>loadfile ([filename [, mode [, env]]])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2048
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2049
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2050 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2051 Similar to <a href="#pdf-load"><code>load</code></a>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2052 but gets the chunk from file <code>filename</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2053 or from the standard input,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2054 if no file name is given.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2055
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2056
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2057
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2058
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2059 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2060 <hr><h3><a name="pdf-next"><code>next (table [, index])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2061
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2062
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2063 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2064 Allows a program to traverse all fields of a table.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2065 Its first argument is a table and its second argument
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2066 is an index in this table.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2067 <code>next</code> returns the next index of the table
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2068 and its associated value.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2069 When called with <b>nil</b> as its second argument,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2070 <code>next</code> returns an initial index
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2071 and its associated value.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2072 When called with the last index,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2073 or with <b>nil</b> in an empty table,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2074 <code>next</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
2075 If the second argument is absent, then it is interpreted as <b>nil</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2076 In particular,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2077 you can use <code>next(t)</code> to check whether a table is empty.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2078
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2079
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2080 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2081 The order in which the indices are enumerated is not specified,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2082 <em>even for numeric indices</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2083 (To traverse a table in numeric order,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2084 use a numerical <b>for</b>.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2085
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2086
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2087 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2088 The behavior of <code>next</code> is undefined if,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2089 during the traversal,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2090 you assign any value to a non-existent field in the table.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2091 You may however modify existing fields.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2092 In particular, you may clear existing fields.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2093
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2094
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2095
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2096
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2097 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2098 <hr><h3><a name="pdf-pairs"><code>pairs (t)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2099
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2100
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2101 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2102 If <code>t</code> has a metamethod <code>__pairs</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2103 calls it with <code>t</code> as argument and returns the first three
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2104 results from the call.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2105
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2106
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2107 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2108 Otherwise,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2109 returns three values: the <a href="#pdf-next"><code>next</code></a> function, the table <code>t</code>, and <b>nil</b>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2110 so that the construction
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2111
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2112 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2113 for k,v in pairs(t) 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
2114 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2115 will iterate over all key&ndash;value pairs of table <code>t</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2116
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2117
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2118 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2119 See function <a href="#pdf-next"><code>next</code></a> for the caveats of modifying
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2120 the table during its traversal.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2121
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2122
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2123
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2124
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2125 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2126 <hr><h3><a name="pdf-pcall"><code>pcall (f [, arg1, &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
2127
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2128
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2129 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2130 Calls function <code>f</code> with
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2131 the given arguments in <em>protected mode</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2132 This means that any error inside&nbsp;<code>f</code> is not propagated;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2133 instead, <code>pcall</code> catches the error
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2134 and returns a status code.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2135 Its first result is the status code (a boolean),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2136 which is true if the call succeeds without errors.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2137 In such case, <code>pcall</code> also returns all results from the call,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2138 after this first result.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2139 In case of any error, <code>pcall</code> returns <b>false</b> plus the error message.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2140
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2141
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2142
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2143
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2144 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2145 <hr><h3><a name="pdf-print"><code>print (&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
2146 Receives any number of arguments
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2147 and prints their values to <code>stdout</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2148 using the <a href="#pdf-tostring"><code>tostring</code></a> function to convert each argument to a string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2149 <code>print</code> is not intended for formatted output,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2150 but only as a quick way to show a value,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2151 for instance for debugging.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2152 For complete control over the output,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2153 use <a href="#pdf-string.format"><code>string.format</code></a> and <a href="#pdf-io.write"><code>io.write</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2154
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2155
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2156
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2157
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2158 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2159 <hr><h3><a name="pdf-rawequal"><code>rawequal (v1, v2)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2160 Checks whether <code>v1</code> is equal to <code>v2</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2161 without invoking any metamethod.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2162 Returns a boolean.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2163
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2164
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2165
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2166
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2167 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2168 <hr><h3><a name="pdf-rawget"><code>rawget (table, index)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2169 Gets the real value of <code>table[index]</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2170 without invoking any metamethod.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2171 <code>table</code> must be a table;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2172 <code>index</code> may be any value.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2173
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2174
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2175
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2176
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2177 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2178 <hr><h3><a name="pdf-rawlen"><code>rawlen (v)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2179 Returns the length of the object <code>v</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2180 which must be a table or a string,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2181 without invoking any metamethod.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2182 Returns an integer.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2183
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2184
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2185
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2186
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2187 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2188 <hr><h3><a name="pdf-rawset"><code>rawset (table, index, value)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2189 Sets the real value of <code>table[index]</code> to <code>value</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2190 without invoking any metamethod.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2191 <code>table</code> must be a table,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2192 <code>index</code> any value different from <b>nil</b> and NaN,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2193 and <code>value</code> any Lua value.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2194
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2195
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2196 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2197 This function returns <code>table</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2198
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2199
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2200
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2201
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2202 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2203 <hr><h3><a name="pdf-select"><code>select (index, &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
2204
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2205
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2206 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2207 If <code>index</code> is a number,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2208 returns all arguments after argument number <code>index</code>;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2209 a negative number indexes from the end (-1 is the last argument).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2210 Otherwise, <code>index</code> must be the string <code>"#"</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2211 and <code>select</code> returns the total number of extra arguments it received.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2212
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2213
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2214
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2215
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2216 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2217 <hr><h3><a name="pdf-setmetatable"><code>setmetatable (table, metatable)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2218
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2219
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2220 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2221 Sets the metatable for the given table.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2222 (You cannot change the metatable of other types from Lua, only from&nbsp;C.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2223 If <code>metatable</code> is <b>nil</b>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2224 removes the metatable of the given table.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2225 If the original metatable has a <code>"__metatable"</code> field,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2226 raises an error.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2227
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2228
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2229 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2230 This function returns <code>table</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2231
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2232
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2233
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2234
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2235 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2236 <hr><h3><a name="pdf-tonumber"><code>tonumber (e [, base])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2237
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2238
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2239 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2240 When called with no <code>base</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2241 <code>tonumber</code> tries to convert its argument to a number.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2242 If the argument is already a number or
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2243 a string convertible to a number,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2244 then <code>tonumber</code> returns this number;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2245 otherwise, 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
2246
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2247
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2248 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2249 The conversion of strings can result in integers or floats,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2250 according to the lexical conventions of Lua (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
2251 (The string may have leading and trailing spaces and a sign.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2252
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2253
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2254 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2255 When called with <code>base</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2256 then <code>e</code> must be a string to be interpreted as
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2257 an integer numeral in that base.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2258 The base may be any integer between 2 and 36, inclusive.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2259 In bases above&nbsp;10, the letter '<code>A</code>' (in either upper or lower case)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2260 represents&nbsp;10, '<code>B</code>' represents&nbsp;11, and so forth,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2261 with '<code>Z</code>' representing 35.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2262 If the string <code>e</code> is not a valid numeral in the given base,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2263 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
2264
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2265
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2266
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2267
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2268 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2269 <hr><h3><a name="pdf-tostring"><code>tostring (v)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2270 Receives a value of any type and
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2271 converts it to a string in a human-readable format.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2272 Floats always produce strings with some
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2273 floating-point indication (either a decimal dot or an exponent).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2274 (For complete control of how numbers are converted,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2275 use <a href="#pdf-string.format"><code>string.format</code></a>.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2276
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2277
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2278 <p>
429
e3a6d9dbd694 rename __tostring to __to_string
Franklin Schmidt <fschmidt@gmail.com>
parents: 428
diff changeset
2279 If the metatable of <code>v</code> has a <code>"__to_string"</code> field,
371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2280 then <code>tostring</code> calls the corresponding value
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2281 with <code>v</code> as argument,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2282 and uses the result of the call as its result.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2283
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2284
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2285
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2286
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2287 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2288 <hr><h3><a name="pdf-type"><code>type (v)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2289 Returns the type of its only argument, coded as a string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2290 The possible results of this function are
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2291 "<code>nil</code>" (a string, not the value <b>nil</b>),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2292 "<code>number</code>",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2293 "<code>string</code>",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2294 "<code>boolean</code>",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2295 "<code>table</code>",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2296 "<code>function</code>",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2297 "<code>thread</code>",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2298 and "<code>userdata</code>".
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2299
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2300
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2301
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2302
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2303 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2304 <hr><h3><a name="pdf-_VERSION"><code>_VERSION</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2305 A global variable (not a function) that
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2306 holds a string containing the current interpreter version.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2307 The current value of this variable is "<code>Lua 5.3</code>".
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2308
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2309
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2310
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2311
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2312 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2313 <hr><h3><a name="pdf-xpcall"><code>xpcall (f, msgh [, arg1, &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
2314
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2315
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2316 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2317 This function is similar to <a href="#pdf-pcall"><code>pcall</code></a>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2318 except that it sets a new message handler <code>msgh</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2319
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2320
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2324
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2325
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2326 <h2>6.2 &ndash; <a name="6.2">Coroutine Manipulation</a></h2>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2327
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2328 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2329 The operations related to coroutines comprise a sub-library of
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2330 the basic library and come inside the table <a name="pdf-coroutine"><code>coroutine</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2331 See <a href="#2.6">&sect;2.6</a> for a general description of coroutines.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2332
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2333
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2334 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2335 <hr><h3><a name="pdf-coroutine.create"><code>coroutine.create (f)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2336
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2337
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2338 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2339 Creates a new coroutine, with body <code>f</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2340 <code>f</code> must be a Lua function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2341 Returns this new coroutine,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2342 an object with type <code>"thread"</code>.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2345
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2346
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2347 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2348 <hr><h3><a name="pdf-coroutine.isyieldable"><code>coroutine.isyieldable ()</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2349
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2350
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2351 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2352 Returns true when the running coroutine can yield.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2353
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2354
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2355 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2356 A running coroutine is yieldable if it is not the main thread and
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2357 it is not inside a non-yieldable C function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2358
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2359
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2360
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2361
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2362 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2363 <hr><h3><a name="pdf-coroutine.resume"><code>coroutine.resume (co [, val1, &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
2364
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2365
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2366 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2367 Starts or continues the execution of coroutine <code>co</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2368 The first time you resume a coroutine,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2369 it starts running its body.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2370 The values <code>val1</code>, ... are passed
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2371 as the arguments to the body function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2372 If the coroutine has yielded,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2373 <code>resume</code> restarts it;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2374 the values <code>val1</code>, ... are passed
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2375 as the results from the yield.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2376
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2377
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2378 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2379 If the coroutine runs without any errors,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2380 <code>resume</code> returns <b>true</b> plus any values passed to <code>yield</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2381 (when the coroutine yields) or any values returned by the body function
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2382 (when the coroutine terminates).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2383 If there is any error,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2384 <code>resume</code> returns <b>false</b> plus the error message.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2385
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2386
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2387
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2388
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2389 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2390 <hr><h3><a name="pdf-coroutine.running"><code>coroutine.running ()</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2391
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2392
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2393 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2394 Returns the running coroutine plus a boolean,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2395 true when the running coroutine is the main one.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2396
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2397
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2398
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2401 <hr><h3><a name="pdf-coroutine.status"><code>coroutine.status (co)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2402
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2403
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2404 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2405 Returns the status of coroutine <code>co</code>, as a string:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2406 <code>"running"</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2407 if the coroutine is running (that is, it called <code>status</code>);
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2408 <code>"suspended"</code>, if the coroutine is suspended in a call to <code>yield</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2409 or if it has not started running yet;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2410 <code>"normal"</code> if the coroutine is active but not running
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2411 (that is, it has resumed another coroutine);
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2412 and <code>"dead"</code> if the coroutine has finished its body function,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2413 or if it has stopped with an error.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2414
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2415
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2416
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2417
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2418 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2419 <hr><h3><a name="pdf-coroutine.wrap"><code>coroutine.wrap (f)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
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 Creates a new coroutine, with body <code>f</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2424 <code>f</code> must be a Lua function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2425 Returns a function that resumes the coroutine 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
2426 Any arguments passed to the function behave as the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2427 extra arguments to <code>resume</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2428 Returns the same values returned by <code>resume</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2429 except the first boolean.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2430 In case of error, propagates the error.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2431
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2432
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2433
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2434
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2435 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2436 <hr><h3><a name="pdf-coroutine.yield"><code>coroutine.yield (&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
2437
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2438
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2439 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2440 Suspends the execution of the calling coroutine.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2441 Any arguments to <code>yield</code> are passed as extra results to <code>resume</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2442
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2443
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2444
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2445
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2446
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2447
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2448
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2449 <h2>6.3 &ndash; <a name="6.3">Modules</a></h2>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2450
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2451 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2452 The package library provides basic
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2453 facilities for loading modules in Lua.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2454 It exports one function directly in the global environment:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2455 <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
2456 Everything else is exported in a table <a name="pdf-package"><code>package</code></a>.
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2460 <hr><h3><a name="pdf-require"><code>require (modname)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2461
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2462
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2463 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2464 Loads the given module.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2465 The function starts by looking into the <a href="#pdf-package.loaded"><code>package.loaded</code></a> table
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2466 to determine whether <code>modname</code> is already loaded.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2467 If it is, then <code>require</code> returns the value stored
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2468 at <code>package.loaded[modname]</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2469 Otherwise, it tries to find a <em>loader</em> for the module.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2470
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2471
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2472 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2473 To find a loader,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2474 <code>require</code> is guided by the <a href="#pdf-package.searchers"><code>package.searchers</code></a> sequence.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2475 By changing this sequence,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2476 we can change how <code>require</code> looks for a module.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2477 The following explanation is based on the default configuration
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2478 for <a href="#pdf-package.searchers"><code>package.searchers</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2479
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2480
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2481 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2482 First <code>require</code> queries <code>package.preload[modname]</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2483 If it has a value,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2484 this value (which must be a function) is the loader.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2485 Otherwise <code>require</code> searches for a Lua loader using the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2486 path stored in <a href="#pdf-package.path"><code>package.path</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2487 If that also fails, it searches for a C&nbsp;loader using the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2488 path stored in <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
2489 If that also fails,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2490 it tries an <em>all-in-one</em> loader (see <a href="#pdf-package.searchers"><code>package.searchers</code></a>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2491
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2492
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2493 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2494 Once a loader is found,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2495 <code>require</code> calls the loader with two arguments:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2496 <code>modname</code> and an extra value dependent on how it got the loader.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2497 (If the loader came from a file,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2498 this extra value is the file name.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2499 If the loader returns any non-nil value,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2500 <code>require</code> assigns the returned value to <code>package.loaded[modname]</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2501 If the loader does not return a non-nil value and
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2502 has not assigned any value to <code>package.loaded[modname]</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2503 then <code>require</code> assigns <b>true</b> to this entry.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2504 In any case, <code>require</code> returns the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2505 final value of <code>package.loaded[modname]</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2506
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2507
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2508 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2509 If there is any error loading or running the module,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2510 or if it cannot find any loader for the module,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2511 then <code>require</code> raises an error.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2512
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2513
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2514
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2515
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2516 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2517 <hr><h3><a name="pdf-package.config"><code>package.config</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2518
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2519
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2520 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2521 A string describing some compile-time configurations for packages.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2522 This string is a sequence of lines:
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 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2525
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2526 <li>The first line is the directory separator string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2527 Default is '<code>\</code>' for Windows and '<code>/</code>' for all other systems.</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2528
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2529 <li>The second line is the character that separates templates in a path.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2530 Default is '<code>;</code>'.</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2531
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2532 <li>The third line is the string that marks the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2533 substitution points in a template.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2534 Default is '<code>?</code>'.</li>
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 <li>The fourth line is a string that, in a path in Windows,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2537 is replaced by the executable's directory.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2538 Default is '<code>!</code>'.</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2539
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2540 <li>The fifth line is a mark to ignore all text after it
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2541 when building the <code>luaopen_</code> function name.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2542 Default is '<code>-</code>'.</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2543
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2544 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2545
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2546
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2547
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2548 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2549 <hr><h3><a name="pdf-package.cpath"><code>package.cpath</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2550
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2551
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2552 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2553 The path used by <a href="#pdf-require"><code>require</code></a> to search for a C&nbsp;loader.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2554
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2555
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2556 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2557 Lua initializes the C&nbsp;path <a href="#pdf-package.cpath"><code>package.cpath</code></a> in the same way
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2558 it initializes the Lua path <a href="#pdf-package.path"><code>package.path</code></a>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2559 using the environment variable <a name="pdf-LUA_CPATH_5_3"><code>LUA_CPATH_5_3</code></a>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2560 or the environment variable <a name="pdf-LUA_CPATH"><code>LUA_CPATH</code></a>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2561 or a default path 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
2562
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2563
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2564
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2565
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2566 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2567 <hr><h3><a name="pdf-package.loaded"><code>package.loaded</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2568
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2569
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2570 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2571 A table used by <a href="#pdf-require"><code>require</code></a> to control which
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2572 modules are already loaded.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2573 When you require a module <code>modname</code> and
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2574 <code>package.loaded[modname]</code> is not false,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2575 <a href="#pdf-require"><code>require</code></a> simply returns the value stored there.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2576
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2577
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2578 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2579 This variable is only a reference to the real table;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2580 assignments to this variable do not change the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2581 table 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
2582
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2583
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2584
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2585
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2586 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2587 <hr><h3><a name="pdf-package.loadlib"><code>package.loadlib (libname, funcname)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2588
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2589
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2590 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2591 Dynamically links the host program with the C&nbsp;library <code>libname</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2592
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2593
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2594 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2595 If <code>funcname</code> is "<code>*</code>",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2596 then it only links with the library,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2597 making the symbols exported by the library
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2598 available to other dynamically linked libraries.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2599 Otherwise,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2600 it looks for a function <code>funcname</code> inside the library
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2601 and returns this function as a C&nbsp;function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2602 So, <code>funcname</code> must follow the <a href="#lua_CFunction"><code>lua_CFunction</code></a> prototype
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2603 (see <a href="#lua_CFunction"><code>lua_CFunction</code></a>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2604
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2605
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2606 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2607 This is a low-level function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2608 It completely bypasses the package and module system.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2609 Unlike <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
2610 it does not perform any path searching and
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2611 does not automatically adds extensions.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2612 <code>libname</code> must be the complete file name of the C&nbsp;library,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2613 including if necessary a path and an extension.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2614 <code>funcname</code> must be the exact name exported by the C&nbsp;library
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2615 (which may depend on the C&nbsp;compiler and linker used).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2616
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2617
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2618 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2619 This function is not supported by Standard&nbsp;C.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2620 As such, it is only available on some platforms
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2621 (Windows, Linux, Mac OS X, Solaris, BSD,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2622 plus other Unix systems that support the <code>dlfcn</code> standard).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2623
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2624
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2625
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2626
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2627 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2628 <hr><h3><a name="pdf-package.path"><code>package.path</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2629
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2630
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2631 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2632 The path used by <a href="#pdf-require"><code>require</code></a> to search for a Lua loader.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2633
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2634
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2635 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2636 At start-up, Lua initializes this variable with
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2637 the value of the environment variable <a name="pdf-LUA_PATH_5_3"><code>LUA_PATH_5_3</code></a> or
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2638 the environment variable <a name="pdf-LUA_PATH"><code>LUA_PATH</code></a> or
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2639 with a default path 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
2640 if those environment variables are not defined.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2641 Any "<code>;;</code>" in the value of the environment variable
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2642 is replaced by the default path.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2643
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2644
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2645
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2646
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2647 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2648 <hr><h3><a name="pdf-package.preload"><code>package.preload</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2649
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2650
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2651 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2652 A table to store loaders for specific modules
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2653 (see <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
2654
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2655
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2656 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2657 This variable is only a reference to the real table;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2658 assignments to this variable do not change the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2659 table 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
2660
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2661
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2662
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2663
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2664 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2665 <hr><h3><a name="pdf-package.searchers"><code>package.searchers</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2666
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2667
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2668 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2669 A table used by <a href="#pdf-require"><code>require</code></a> to control how to load modules.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2670
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2671
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2672 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2673 Each entry in this table is a <em>searcher function</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2674 When looking for a module,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2675 <a href="#pdf-require"><code>require</code></a> calls each of these searchers in ascending order,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2676 with the module name (the argument given to <a href="#pdf-require"><code>require</code></a>) as its
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2677 sole parameter.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2678 The function can return another function (the module <em>loader</em>)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2679 plus an extra value that will be passed to that loader,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2680 or a string explaining why it did not find that module
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2681 (or <b>nil</b> if it has nothing to say).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2682
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2683
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2684 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2685 Lua initializes this table with four searcher functions.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2686
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2687
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2688 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2689 The first searcher simply looks for a loader in the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2690 <a href="#pdf-package.preload"><code>package.preload</code></a> table.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2691
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2692
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2693 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2694 The second searcher looks for a loader as a Lua library,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2695 using the path stored at <a href="#pdf-package.path"><code>package.path</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2696 The search is done as described in function <a href="#pdf-package.searchpath"><code>package.searchpath</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2697
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2698
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2699 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2700 The third searcher looks for a loader as a C&nbsp;library,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2701 using the path given by the variable <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
2702 Again,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2703 the search is done as described in function <a href="#pdf-package.searchpath"><code>package.searchpath</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2704 For instance,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2705 if the C&nbsp;path is the string
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2706
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2707 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2708 "./?.so;./?.dll;/usr/local/?/init.so"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2709 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2710 the searcher for module <code>foo</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2711 will try to open the files <code>./foo.so</code>, <code>./foo.dll</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2712 and <code>/usr/local/foo/init.so</code>, in that order.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2713 Once it finds a C&nbsp;library,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2714 this searcher first uses a dynamic link facility to link the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2715 application with the library.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2716 Then it tries to find a C&nbsp;function inside the library to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2717 be used as the loader.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2718 The name of this C&nbsp;function is the string "<code>luaopen_</code>"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2719 concatenated with a copy of the module name where each dot
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2720 is replaced by an underscore.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2721 Moreover, if the module name has a hyphen,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2722 its suffix after (and including) the first hyphen is removed.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2723 For instance, if the module name is <code>a.b.c-v2.1</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2724 the function name will be <code>luaopen_a_b_c</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2725
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2726
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2727 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2728 The fourth searcher tries an <em>all-in-one loader</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2729 It searches the C&nbsp;path for a library for
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2730 the root name of the given module.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2731 For instance, when requiring <code>a.b.c</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2732 it will search for a C&nbsp;library for <code>a</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2733 If found, it looks into it for an open function for
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2734 the submodule;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2735 in our example, that would be <code>luaopen_a_b_c</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2736 With this facility, a package can pack several C&nbsp;submodules
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2737 into one single library,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2738 with each submodule keeping its original open function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2739
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2742 All searchers except the first one (preload) return as the extra value
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2743 the file name where the module was found,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2744 as returned by <a href="#pdf-package.searchpath"><code>package.searchpath</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2745 The first searcher returns no extra value.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2746
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2747
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2750 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2751 <hr><h3><a name="pdf-package.searchpath"><code>package.searchpath (name, path [, sep [, rep]])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2752
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2753
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2754 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2755 Searches for the given <code>name</code> in the given <code>path</code>.
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2759 A path is a string containing a sequence of
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2760 <em>templates</em> separated by semicolons.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2761 For each template,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2762 the function replaces each interrogation mark (if any)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2763 in the template with a copy of <code>name</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2764 wherein all occurrences of <code>sep</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2765 (a dot, by default)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2766 were replaced by <code>rep</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2767 (the system's directory separator, by default),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2768 and then tries to open the resulting file name.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2769
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2770
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2771 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2772 For instance, if the path is the string
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2773
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2774 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2775 "./?.lua;./?.lc;/usr/local/?/init.lua"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2776 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2777 the search for the name <code>foo.a</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2778 will try to open the files
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2779 <code>./foo/a.lua</code>, <code>./foo/a.lc</code>, and
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2780 <code>/usr/local/foo/a/init.lua</code>, in that order.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2781
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2782
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2783 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2784 Returns the resulting name of the first file that it can
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2785 open in read mode (after closing the file),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2786 or <b>nil</b> plus an error message if none succeeds.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2787 (This error message lists all file names it tried to open.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2788
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2789
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2790
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2791
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2792
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2793
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2794
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2795 <h2>6.4 &ndash; <a name="6.4">String Manipulation</a></h2>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2796
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2797 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2798 This library provides generic functions for string manipulation,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2799 such as finding and extracting substrings, and pattern matching.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2800 When indexing a string in Lua, the first character is at position&nbsp;1
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2801 (not at&nbsp;0, as in C).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2802 Indices are allowed to be negative and are interpreted as indexing backwards,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2803 from the end of the string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2804 Thus, the last character is at position -1, and so on.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2805
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2806
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2807 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2808 The string library provides all its functions inside the table
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2809 <a name="pdf-string"><code>string</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2810 It also sets a metatable for strings
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2811 where the <code>__index</code> field points to the <code>string</code> table.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2812 Therefore, you can use the string functions in object-oriented style.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2813 For instance, <code>string.byte(s,i)</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2814 can be written as <code>s:byte(i)</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2815
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2816
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2817 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2818 The string library assumes one-byte character encodings.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2819
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2820
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2821 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2822 <hr><h3><a name="pdf-string.byte"><code>string.byte (s [, i [, j]])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2823 Returns the internal numerical codes of the characters <code>s[i]</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2824 <code>s[i+1]</code>, ..., <code>s[j]</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2825 The default value for <code>i</code> is&nbsp;1;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2826 the default value for <code>j</code> is&nbsp;<code>i</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2827 These indices are corrected
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2828 following the same rules of function <a href="#pdf-string.sub"><code>string.sub</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2829
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 Numerical codes are not necessarily portable across platforms.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2837 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2838 <hr><h3><a name="pdf-string.char"><code>string.char (&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
2839 Receives zero or more integers.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2840 Returns a string with length equal to the number of arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2841 in which each character has the internal numerical code equal
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2842 to its corresponding argument.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2843
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2846 Numerical codes are not necessarily portable across platforms.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2847
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2848
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2851 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2852 <hr><h3><a name="pdf-string.dump"><code>string.dump (function [, strip])</code></a></h3>
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2856 Returns a string containing a binary representation
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2857 (a <em>binary chunk</em>)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2858 of the given function,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2859 so that a later <a href="#pdf-load"><code>load</code></a> on this string returns
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2860 a copy of the function (but with new upvalues).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2861 If <code>strip</code> is a true value,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2862 the binary representation is created without debug information
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2863 about the function
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2864 (local variable names, lines, etc.).
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2867 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2868 Functions with upvalues have only their number of upvalues saved.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2869 When (re)loaded,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2870 those upvalues receive fresh instances containing <b>nil</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2871 (You can use the debug library to serialize
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2872 and reload the upvalues of a function
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2873 in a way adequate to your needs.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2874
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2875
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2876
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2879 <hr><h3><a name="pdf-string.find"><code>string.find (s, pattern [, init [, plain]])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2880
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2881
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2882 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2883 Looks for the first match of
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2884 <code>pattern</code> (see <a href="#6.4.1">&sect;6.4.1</a>) in the string <code>s</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2885 If it finds a match, then <code>find</code> returns the indices of&nbsp;<code>s</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2886 where this occurrence starts and ends;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2887 otherwise, 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
2888 A third, optional numerical argument <code>init</code> specifies
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2889 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
2890 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
2891 A value of <b>true</b> as a fourth, optional argument <code>plain</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2892 turns off the pattern matching facilities,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2893 so the function does a plain "find substring" operation,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2894 with no characters in <code>pattern</code> being considered magic.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2895 Note that if <code>plain</code> is given, then <code>init</code> must be given as well.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2896
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2897
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2898 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2899 If the pattern has captures,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2900 then in a successful match
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2901 the captured values are also returned,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2902 after the two indices.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2903
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2904
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2905
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2906
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2907 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2908 <hr><h3><a name="pdf-string.format"><code>string.format (formatstring, &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
2909
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2910
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2911 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2912 Returns a formatted version of its variable number of arguments
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2913 following the description given in its first argument (which must be a string).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2914 The format string follows the same rules as the ISO&nbsp;C function <code>sprintf</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2915 The only differences are that the options/modifiers
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2916 <code>*</code>, <code>h</code>, <code>L</code>, <code>l</code>, <code>n</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2917 and <code>p</code> are not supported
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2918 and that there is an extra option, <code>q</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2919 The <code>q</code> option formats a string between double quotes,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2920 using escape sequences when necessary to ensure that
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2921 it can safely be read back by the Lua interpreter.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2922 For instance, the call
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2923
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2924 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2925 string.format('%q', 'a string with "quotes" and \n new line')
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2926 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2927 may produce the string:
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 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2930 "a string with \"quotes\" and \
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2931 new line"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2932 </pre>
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 Options
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2936 <code>A</code> and <code>a</code> (when available),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2937 <code>E</code>, <code>e</code>, <code>f</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2938 <code>G</code>, and <code>g</code> all expect a number as argument.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2939 Options <code>c</code>, <code>d</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2940 <code>i</code>, <code>o</code>, <code>u</code>, <code>X</code>, and <code>x</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2941 expect an integer.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2942 Option <code>q</code> expects a string;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2943 option <code>s</code> expects a string without embedded zeros.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2944 If the argument to option <code>s</code> is not a string,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2945 it is converted to one following the same rules of <a href="#pdf-tostring"><code>tostring</code></a>.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2948
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 <hr><h3><a name="pdf-string.gmatch"><code>string.gmatch (s, pattern)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2952 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
2953 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
2954 returns the next captures from <code>pattern</code> (see <a href="#6.4.1">&sect;6.4.1</a>)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2955 over the string <code>s</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2956 If <code>pattern</code> specifies no captures,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2957 then the whole match is produced in each call.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2958
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2959
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2960 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2961 As an example, the following loop
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2962 will iterate over all the words from string <code>s</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2963 printing one per line:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2964
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2965 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2966 s = "hello world from Lua"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2967 for w in string.gmatch(s, "%a+") do
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2968 print(w)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2969 end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2970 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2971 The next example collects all pairs <code>key=value</code> from the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2972 given string into a table:
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 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2975 t = {}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2976 s = "from=world, to=Lua"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2977 for k, v in string.gmatch(s, "(%w+)=(%w+)") do
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2978 t[k] = v
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2979 end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2980 </pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2981
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2982 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2983 For this function, a caret '<code>^</code>' at the start of a pattern does not
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2984 work as an anchor, as this would prevent the iteration.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2987
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2988
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2989 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2990 <hr><h3><a name="pdf-string.gsub"><code>string.gsub (s, pattern, repl [, n])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2991 Returns a copy of <code>s</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2992 in which all (or the first <code>n</code>, if given)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2993 occurrences of the <code>pattern</code> (see <a href="#6.4.1">&sect;6.4.1</a>) have been
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2994 replaced by a replacement string specified by <code>repl</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2995 which can be a string, a table, or a function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2996 <code>gsub</code> also returns, as its second value,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2997 the total number of matches that occurred.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
2998 The name <code>gsub</code> comes from <em>Global SUBstitution</em>.
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3002 If <code>repl</code> is a string, then its value is used for replacement.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3003 The character&nbsp;<code>%</code> works as an escape character:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3004 any sequence in <code>repl</code> of the form <code>%<em>d</em></code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3005 with <em>d</em> between 1 and 9,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3006 stands for the value of the <em>d</em>-th captured substring.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3007 The sequence <code>%0</code> stands for the whole match.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3008 The sequence <code>%%</code> stands for a single&nbsp;<code>%</code>.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3011 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3012 If <code>repl</code> is a table, then the table is queried for every match,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3013 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
3014
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3017 If <code>repl</code> is a function, then this function is called every time a
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3018 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
3019 in order.
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3023 In any case,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3024 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
3025 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
3026
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3027
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3028 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3029 If the value returned by the table query or by the function call
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3030 is a string or a number,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3031 then it is used as the replacement string;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3032 otherwise, if it is <b>false</b> or <b>nil</b>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3033 then there is no replacement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3034 (that is, the original match is kept in the string).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3035
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3036
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3037 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3038 Here are some examples:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3039
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3040 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3041 x = string.gsub("hello world", "(%w+)", "%1 %1")
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3042 --&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
3043
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3044 x = string.gsub("hello world", "%w+", "%0 %0", 1)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3045 --&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
3046
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3047 x = string.gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1")
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3048 --&gt; x="world hello Lua from"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3049
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3050 x = string.gsub("home = $HOME, user = $USER", "%$(%w+)", os.getenv)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3051 --&gt; x="home = /home/roberto, user = roberto"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3052
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3053 x = string.gsub("4+5 = $return 4+5$", "%$(.-)%$", function (s)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3054 return load(s)()
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3055 end)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3056 --&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
3057
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3058 local t = {name="lua", version="5.3"}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3059 x = string.gsub("$name-$version.tar.gz", "%$(%w+)", t)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3060 --&gt; x="lua-5.3.tar.gz"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3061 </pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3062
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3063
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3066 <hr><h3><a name="pdf-string.len"><code>string.len (s)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3067 Receives a string and returns its length.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3068 The empty string <code>""</code> has length 0.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3069 Embedded zeros are counted,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3070 so <code>"a\000bc\000"</code> has length 5.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3074
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3075 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3076 <hr><h3><a name="pdf-string.lower"><code>string.lower (s)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3077 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
3078 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
3079 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
3080 The definition of what an uppercase 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
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3084
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3085 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3086 <hr><h3><a name="pdf-string.match"><code>string.match (s, pattern [, init])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3087 Looks for the first <em>match</em> of
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3088 <code>pattern</code> (see <a href="#6.4.1">&sect;6.4.1</a>) in the string <code>s</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3089 If it finds one, then <code>match</code> returns
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3090 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
3091 otherwise 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
3092 If <code>pattern</code> specifies no captures,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3093 then the whole match is returned.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3094 A third, optional numerical argument <code>init</code> specifies
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3095 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
3096 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
3097
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3098
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3102 <hr><h3><a name="pdf-string.pack"><code>string.pack (fmt, v1, v2, &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
3103
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3104
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3105 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3106 Returns a binary string containing the values <code>v1</code>, <code>v2</code>, etc.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3107 packed (that is, serialized in binary form)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3108 according to the format string <code>fmt</code> (see <a href="#6.4.2">&sect;6.4.2</a>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3109
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3110
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3111
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3112
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3113 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3114 <hr><h3><a name="pdf-string.packsize"><code>string.packsize (fmt)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3115
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3116
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3117 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3118 Returns the size of a string resulting from <a href="#pdf-string.pack"><code>string.pack</code></a>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3119 with the given format.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3120 The format string cannot have the variable-length options
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3121 '<code>s</code>' or '<code>z</code>' (see <a href="#6.4.2">&sect;6.4.2</a>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3122
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3123
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3124
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3127 <hr><h3><a name="pdf-string.rep"><code>string.rep (s, n [, sep])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3128 Returns a string that is the concatenation of <code>n</code> copies of
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3129 the string <code>s</code> separated by the string <code>sep</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3130 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
3131 (that is, no separator).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3132 Returns the empty string if <code>n</code> is not positive.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3133
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3134
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3135
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3136
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3137 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3138 <hr><h3><a name="pdf-string.reverse"><code>string.reverse (s)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3139 Returns a string that is the string <code>s</code> reversed.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3140
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3141
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3144 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3145 <hr><h3><a name="pdf-string.sub"><code>string.sub (s, i [, j])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3146 Returns the substring of <code>s</code> that
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3147 starts at <code>i</code> and continues until <code>j</code>;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3148 <code>i</code> and <code>j</code> can be negative.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3149 If <code>j</code> is absent, then it is assumed to be equal to -1
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3150 (which is the same as the string length).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3151 In particular,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3152 the call <code>string.sub(s,1,j)</code> returns a prefix of <code>s</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3153 with length <code>j</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3154 and <code>string.sub(s, -i)</code> returns a suffix of <code>s</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3155 with length <code>i</code>.
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 If, after the translation of negative indices,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3160 <code>i</code> is less than 1,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3161 it is corrected to 1.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3162 If <code>j</code> is greater than the string length,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3163 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
3164 If, after these corrections,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3165 <code>i</code> is greater than <code>j</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3166 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
3167
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3168
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3169
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3172 <hr><h3><a name="pdf-string.unpack"><code>string.unpack (fmt, s [, pos])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3173
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3174
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3175 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3176 Returns the values packed in string <code>s</code> (see <a href="#pdf-string.pack"><code>string.pack</code></a>)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3177 according to the format string <code>fmt</code> (see <a href="#6.4.2">&sect;6.4.2</a>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3178 An optional <code>pos</code> marks where
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3179 to start reading in <code>s</code> (default is 1).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3180 After the read values,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3181 this function also returns the index of the first unread byte in <code>s</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3182
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3187 <hr><h3><a name="pdf-string.upper"><code>string.upper (s)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3188 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
3189 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
3190 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
3191 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
3192
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 <h3>6.4.1 &ndash; <a name="6.4.1">Patterns</a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3198
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3199 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3200 Patterns in Lua are described by regular strings,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3201 which are interpreted as patterns by the pattern-matching functions
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3202 <a href="#pdf-string.find"><code>string.find</code></a>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3203 <a href="#pdf-string.gmatch"><code>string.gmatch</code></a>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3204 <a href="#pdf-string.gsub"><code>string.gsub</code></a>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3205 and <a href="#pdf-string.match"><code>string.match</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3206 This section describes the syntax and the meaning
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3207 (that is, what they match) of these strings.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3210
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3211 <h4>Character Class:</h4><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3212 A <em>character class</em> is used to represent a set of characters.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3213 The following combinations are allowed in describing a character class:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3214
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3215 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3216
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3217 <li><b><em>x</em>: </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3218 (where <em>x</em> is not one of the <em>magic characters</em>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3219 <code>^$()%.[]*+-?</code>)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3220 represents the character <em>x</em> itself.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3221 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3222
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3223 <li><b><code>.</code>: </b> (a dot) represents all characters.</li>
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 <li><b><code>%a</code>: </b> represents all letters.</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3226
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3227 <li><b><code>%c</code>: </b> represents all control characters.</li>
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 <li><b><code>%d</code>: </b> represents all digits.</li>
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 <li><b><code>%g</code>: </b> represents all printable characters except space.</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3232
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3233 <li><b><code>%l</code>: </b> represents all lowercase letters.</li>
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 <li><b><code>%p</code>: </b> represents all punctuation characters.</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3236
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3237 <li><b><code>%s</code>: </b> represents all space characters.</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3238
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3239 <li><b><code>%u</code>: </b> represents all uppercase letters.</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3240
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3241 <li><b><code>%w</code>: </b> represents all alphanumeric characters.</li>
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 <li><b><code>%x</code>: </b> represents all hexadecimal digits.</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3244
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3245 <li><b><code>%<em>x</em></code>: </b> (where <em>x</em> is any non-alphanumeric character)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3246 represents the character <em>x</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3247 This is the standard way to escape the magic characters.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3248 Any non-alphanumeric character
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3249 (including all punctuations, even the non-magical)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3250 can be preceded by a '<code>%</code>'
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3251 when used to represent itself in a pattern.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3252 </li>
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 <li><b><code>[<em>set</em>]</code>: </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3255 represents the class which is the union of all
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3256 characters in <em>set</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3257 A range of characters can be specified by
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3258 separating the end characters of the range,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3259 in ascending order, with a '<code>-</code>'.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3260 All classes <code>%</code><em>x</em> described above can also be used as
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3261 components in <em>set</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3262 All other characters in <em>set</em> represent themselves.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3263 For example, <code>[%w_]</code> (or <code>[_%w]</code>)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3264 represents all alphanumeric characters plus the underscore,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3265 <code>[0-7]</code> represents the octal digits,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3266 and <code>[0-7%l%-]</code> represents the octal digits plus
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3267 the lowercase letters plus the '<code>-</code>' character.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3268
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3269
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3270 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3271 The interaction between ranges and classes is not defined.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3272 Therefore, patterns like <code>[%a-z]</code> or <code>[a-%%]</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3273 have no meaning.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3274 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3275
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3276 <li><b><code>[^<em>set</em>]</code>: </b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3277 represents the complement of <em>set</em>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3278 where <em>set</em> is interpreted as above.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3279 </li>
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 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3282 For all classes represented by single letters (<code>%a</code>, <code>%c</code>, etc.),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3283 the corresponding uppercase letter represents the complement of the class.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3284 For instance, <code>%S</code> represents all non-space characters.
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3288 The definitions of letter, space, and other character groups
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3289 depend on the current locale.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3290 In particular, the class <code>[a-z]</code> may not be equivalent to <code>%l</code>.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3294
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3295
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3296 <h4>Pattern Item:</h4><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3297 A <em>pattern item</em> can be
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3298
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3299 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3300
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3301 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3302 a single character class,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3303 which matches any single character in the class;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3304 </li>
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 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3307 a single character class followed by '<code>*</code>',
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3308 which matches zero or more repetitions of characters in the class.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3309 These repetition items will always match the longest possible sequence;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3310 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3311
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3312 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3313 a single character class followed by '<code>+</code>',
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3314 which matches one or more repetitions of characters in the class.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3315 These repetition items will always match the longest possible sequence;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3316 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3317
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3318 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3319 a single character class followed by '<code>-</code>',
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3320 which also matches zero or more repetitions of characters in the class.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3321 Unlike '<code>*</code>',
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3322 these repetition items will always match the shortest possible sequence;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3323 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3324
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3325 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3326 a single character class followed by '<code>?</code>',
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3327 which matches zero or one occurrence of a character in the class.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3328 It always matches one occurrence if possible;
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>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3332 <code>%<em>n</em></code>, for <em>n</em> between 1 and 9;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3333 such item matches a substring equal to the <em>n</em>-th captured string
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3334 (see below);
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>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3338 <code>%b<em>xy</em></code>, where <em>x</em> and <em>y</em> are two distinct characters;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3339 such item matches strings that start with&nbsp;<em>x</em>, end with&nbsp;<em>y</em>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3340 and where the <em>x</em> and <em>y</em> are <em>balanced</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3341 This means that, if one reads the string from left to right,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3342 counting <em>+1</em> for an <em>x</em> and <em>-1</em> for a <em>y</em>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3343 the ending <em>y</em> is the first <em>y</em> where the count reaches 0.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3344 For instance, the item <code>%b()</code> matches expressions with
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3345 balanced parentheses.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3346 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3347
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 <code>%f[<em>set</em>]</code>, a <em>frontier pattern</em>;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3350 such item matches an empty string at any position such that
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3351 the next character belongs to <em>set</em>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3352 and the previous character does not belong to <em>set</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3353 The set <em>set</em> is interpreted as previously described.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3354 The beginning and the end of the subject are handled as if
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3355 they were the character '<code>\0</code>'.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3356 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3357
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3358 </ul>
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3361
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3362
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3363 <h4>Pattern:</h4><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3364 A <em>pattern</em> is a sequence of pattern items.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3365 A caret '<code>^</code>' at the beginning of a pattern anchors the match at the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3366 beginning of the subject string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3367 A '<code>$</code>' at the end of a pattern anchors the match at the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3368 end of the subject string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3369 At other positions,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3370 '<code>^</code>' and '<code>$</code>' have no special meaning and represent themselves.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3371
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3372
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3373
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3374
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 <h4>Captures:</h4><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3377 A pattern can contain sub-patterns enclosed in parentheses;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3378 they describe <em>captures</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3379 When a match succeeds, the substrings of the subject string
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3380 that match captures are stored (<em>captured</em>) for future use.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3381 Captures are numbered according to their left parentheses.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3382 For instance, in the pattern <code>"(a*(.)%w(%s*))"</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3383 the part of the string matching <code>"a*(.)%w(%s*)"</code> is
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3384 stored as the first capture (and therefore has number&nbsp;1);
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3385 the character matching "<code>.</code>" is captured with number&nbsp;2,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3386 and the part matching "<code>%s*</code>" has number&nbsp;3.
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3390 As a special case, the empty capture <code>()</code> captures
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3391 the current string position (a number).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3392 For instance, if we apply the pattern <code>"()aa()"</code> on the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3393 string <code>"flaaap"</code>, there will be two captures: 3&nbsp;and&nbsp;5.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3394
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3395
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3396
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
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3401 <h3>6.4.2 &ndash; <a name="6.4.2">Format Strings for Pack and Unpack</a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3402
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3403 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3404 The first argument to <a href="#pdf-string.pack"><code>string.pack</code></a>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3405 <a href="#pdf-string.packsize"><code>string.packsize</code></a>, and <a href="#pdf-string.unpack"><code>string.unpack</code></a>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3406 is a format string,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3407 which describes the layout of the structure being created or read.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3408
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3411 A format string is a sequence of conversion options.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3412 The conversion options are as follows:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3413
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3414 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3415 <li><b><code>&lt;</code>: </b>sets little endian</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3416 <li><b><code>&gt;</code>: </b>sets big endian</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3417 <li><b><code>=</code>: </b>sets native endian</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3418 <li><b><code>![<em>n</em>]</code>: </b>sets maximum alignment to <code>n</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3419 (default is native alignment)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3420 <li><b><code>b</code>: </b>a signed byte (<code>char</code>)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3421 <li><b><code>B</code>: </b>an unsigned byte (<code>char</code>)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3422 <li><b><code>h</code>: </b>a signed <code>short</code> (native size)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3423 <li><b><code>H</code>: </b>an unsigned <code>short</code> (native size)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3424 <li><b><code>l</code>: </b>a signed <code>long</code> (native size)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3425 <li><b><code>L</code>: </b>an unsigned <code>long</code> (native size)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3426 <li><b><code>j</code>: </b>a <code>lua_Integer</code></li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3427 <li><b><code>J</code>: </b>a <code>lua_Unsigned</code></li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3428 <li><b><code>T</code>: </b>a <code>size_t</code> (native size)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3429 <li><b><code>i[<em>n</em>]</code>: </b>a signed <code>int</code> with <code>n</code> bytes
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3430 (default is native size)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3431 <li><b><code>I[<em>n</em>]</code>: </b>an unsigned <code>int</code> with <code>n</code> bytes
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3432 (default is native size)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3433 <li><b><code>f</code>: </b>a <code>float</code> (native size)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3434 <li><b><code>d</code>: </b>a <code>double</code> (native size)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3435 <li><b><code>n</code>: </b>a <code>lua_Number</code></li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3436 <li><b><code>c<em>n</em></code>: </b>a fixed-sized string with <code>n</code> bytes</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3437 <li><b><code>z</code>: </b>a zero-terminated string</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3438 <li><b><code>s[<em>n</em>]</code>: </b>a string preceded by its length
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3439 coded as an unsigned integer with <code>n</code> bytes
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3440 (default is a <code>size_t</code>)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3441 <li><b><code>x</code>: </b>one byte of padding</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3442 <li><b><code>X<em>op</em></code>: </b>an empty item that aligns
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3443 according to option <code>op</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3444 (which is otherwise ignored)</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3445 <li><b>'<code> </code>': </b>(empty space) ignored</li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3446 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3447 (A "<code>[<em>n</em>]</code>" means an optional integral numeral.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3448 Except for padding, spaces, and configurations
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3449 (options "<code>xX &lt;=&gt;!</code>"),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3450 each option corresponds to an argument (in <a href="#pdf-string.pack"><code>string.pack</code></a>)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3451 or a result (in <a href="#pdf-string.unpack"><code>string.unpack</code></a>).
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3454 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3455 For options "<code>!<em>n</em></code>", "<code>s<em>n</em></code>", "<code>i<em>n</em></code>", and "<code>I<em>n</em></code>",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3456 <code>n</code> can be any integer between 1 and 16.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3457 All integral options check overflows;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3458 <a href="#pdf-string.pack"><code>string.pack</code></a> checks whether the given value fits in the given size;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3459 <a href="#pdf-string.unpack"><code>string.unpack</code></a> checks whether the read value fits in a Lua integer.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3460
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3461
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3462 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3463 Any format string starts as if prefixed by "<code>!1=</code>",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3464 that is,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3465 with maximum alignment of 1 (no alignment)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3466 and native endianness.
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 Alignment works as follows:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3471 For each option,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3472 the format gets extra padding until the data starts
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3473 at an offset that is a multiple of the minimum between the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3474 option size and the maximum alignment;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3475 this minimum must be a power of 2.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3476 Options "<code>c</code>" and "<code>z</code>" are not aligned;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3477 option "<code>s</code>" follows the alignment of its starting integer.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3478
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3479
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3480 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3481 All padding is filled with zeros by <a href="#pdf-string.pack"><code>string.pack</code></a>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3482 (and ignored by <a href="#pdf-string.unpack"><code>string.unpack</code></a>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3483
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3484
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3485
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3486
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3487
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3488
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 <h2>6.5 &ndash; <a name="6.5">UTF-8 Support</a></h2>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3491
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3492 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3493 This library provides basic support for UTF-8 encoding.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3494 It provides all its functions inside the table <a name="pdf-utf8"><code>utf8</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3495 This library does not provide any support for Unicode other
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3496 than the handling of the encoding.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3497 Any operation that needs the meaning of a character,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3498 such as character classification, is outside its scope.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3499
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3500
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3501 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3502 Unless stated otherwise,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3503 all functions that expect a byte position as a parameter
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3504 assume that the given position is either the start of a byte sequence
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3505 or one plus the length of the subject string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3506 As in the string library,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3507 negative indices count from the end of the string.
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3511 <hr><h3><a name="pdf-utf8.char"><code>utf8.char (&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
3512 Receives zero or more integers,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3513 converts each one to its corresponding UTF-8 byte sequence
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3514 and returns a string with the concatenation of all these sequences.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3517
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3518
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3519 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3520 <hr><h3><a name="pdf-utf8.charpattern"><code>utf8.charpattern</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3521 The pattern (a string, not a function) "<code>[\0-\x7F\xC2-\xF4][\x80-\xBF]*</code>"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3522 (see <a href="#6.4.1">&sect;6.4.1</a>),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3523 which matches exactly one UTF-8 byte sequence,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3524 assuming that the subject is a valid UTF-8 string.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3527
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3530 <hr><h3><a name="pdf-utf8.codes"><code>utf8.codes (s)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3531
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3532
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3533 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3534 Returns values so that the construction
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3535
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3536 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3537 for p, c in utf8.codes(s) 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
3538 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3539 will iterate over all characters in string <code>s</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3540 with <code>p</code> being the position (in bytes) and <code>c</code> the code point
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3541 of each character.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3542 It raises an error if it meets any invalid byte sequence.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3543
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3544
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3545
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3548 <hr><h3><a name="pdf-utf8.codepoint"><code>utf8.codepoint (s [, i [, j]])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3549 Returns the codepoints (as integers) from all characters in <code>s</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3550 that start between byte position <code>i</code> and <code>j</code> (both included).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3551 The default for <code>i</code> is 1 and for <code>j</code> is <code>i</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3552 It raises an error if it meets any invalid byte sequence.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3555
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3556
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3557 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3558 <hr><h3><a name="pdf-utf8.len"><code>utf8.len (s [, i [, j]])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3559 Returns the number of UTF-8 characters in string <code>s</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3560 that start between positions <code>i</code> and <code>j</code> (both inclusive).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3561 The default for <code>i</code> is 1 and for <code>j</code> is -1.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3562 If it finds any invalid byte sequence,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3563 returns a false value plus the position of the first invalid byte.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3566
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3567
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3568 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3569 <hr><h3><a name="pdf-utf8.offset"><code>utf8.offset (s, n [, i])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3570 Returns the position (in bytes) where the encoding of the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3571 <code>n</code>-th character of <code>s</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3572 (counting from position <code>i</code>) starts.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3573 A negative <code>n</code> gets characters before position <code>i</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3574 The default for <code>i</code> is 1 when <code>n</code> is non-negative
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3575 and <code>#s + 1</code> otherwise,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3576 so that <code>utf8.offset(s, -n)</code> gets the offset of the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3577 <code>n</code>-th character from the end of the string.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3578 If the specified character is neither in the subject
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3579 nor right after its end,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3580 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
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 As a special case,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3585 when <code>n</code> is 0 the function returns the start of the encoding
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3586 of the character that contains the <code>i</code>-th byte of <code>s</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3587
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3588
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3589 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3590 This function assumes that <code>s</code> is a valid UTF-8 string.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3595
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 <h2>6.6 &ndash; <a name="6.6">Table Manipulation</a></h2>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3599
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3600 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3601 This library provides generic functions for table manipulation.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3602 It provides all its functions inside the table <a name="pdf-table"><code>table</code></a>.
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3606 Remember that, whenever an operation needs the length of a table,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3607 the table must be a proper sequence
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3608 or have a <code>__len</code> metamethod (see <a href="#3.4.7">&sect;3.4.7</a>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3609 All functions ignore non-numeric keys
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3610 in the tables given as arguments.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3611
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3612
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3613 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3614 <hr><h3><a name="pdf-table.concat"><code>table.concat (list [, sep [, i [, j]]])</code></a></h3>
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3618 Given a list where all elements are strings or numbers,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3619 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
3620 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
3621 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
3622 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
3623 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
3624
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3625
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3626
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3627
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3628 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3629 <hr><h3><a name="pdf-table.insert"><code>table.insert (list, [pos,] value)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3630
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3631
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3632 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3633 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
3634 shifting up the elements
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3635 <code>list[pos], list[pos+1], &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
3636 The default value for <code>pos</code> is <code>#list+1</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3637 so that a call <code>table.insert(t,x)</code> inserts <code>x</code> at the end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3638 of list <code>t</code>.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3642
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3643 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3644 <hr><h3><a name="pdf-table.move"><code>table.move (a1, f, e, t [,a2])</code></a></h3>
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 Moves elements from table <code>a1</code> to table <code>a2</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3649 This function performs the equivalent to the following
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3650 multiple assignment:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3651 <code>a2[t],&middot;&middot;&middot; = a1[f],&middot;&middot;&middot;,a1[e]</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3652 The default for <code>a2</code> is <code>a1</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3653 The destination range can overlap with the source range.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3654 Index <code>f</code> must be positive.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3655
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3659 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3660 <hr><h3><a name="pdf-table.pack"><code>table.pack (&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
3661
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3662
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3663 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3664 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
3665 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
3666 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
3667
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3671 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3672 <hr><h3><a name="pdf-table.remove"><code>table.remove (list [, pos])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3673
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3674
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3675 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3676 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
3677 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
3678 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
3679 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
3680 <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
3681 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
3682 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
3683 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
3684 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
3685
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3686
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3687 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3688 The default value for <code>pos</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
3689 so that a call <code>table.remove(l)</code> removes the last element
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3690 of list <code>l</code>.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3694
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3695 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3696 <hr><h3><a name="pdf-table.sort"><code>table.sort (list [, comp])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3697
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3698
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3699 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3700 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
3701 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
3702 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
3703 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
3704 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
3705 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
3706 (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
3707 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
3708 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
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3712 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
3713 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
3714 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
3715
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3716
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3717
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3718
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3719 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3720 <hr><h3><a name="pdf-table.unpack"><code>table.unpack (list [, i [, j]])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3721
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3722
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3723 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3724 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
3725 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
3726
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3727 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3728 return list[i], list[i+1], &middot;&middot;&middot;, list[j]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3729 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3730 By default, <code>i</code> is&nbsp;1 and <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
3731
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3732
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3733
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3734
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3735
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3736
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 <h2>6.7 &ndash; <a name="6.7">Mathematical Functions</a></h2>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3739
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3740 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3741 This library provides basic mathematical functions.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3742 It provides all its functions and constants inside the table <a name="pdf-math"><code>math</code></a>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3743 Functions with the annotation "<code>integer/float</code>" give
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3744 integer results for integer arguments
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3745 and float results for float (or mixed) arguments.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3746 Rounding functions
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3747 (<a href="#pdf-math.ceil"><code>math.ceil</code></a>, <a href="#pdf-math.floor"><code>math.floor</code></a>, and <a href="#pdf-math.modf"><code>math.modf</code></a>)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3748 return an integer when the result fits in the range of an integer,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3749 or a float otherwise.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3750
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3753 <hr><h3><a name="pdf-math.abs"><code>math.abs (x)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3754
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3755
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3756 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3757 Returns the absolute value of <code>x</code>. (integer/float)
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3761
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3762 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3763 <hr><h3><a name="pdf-math.acos"><code>math.acos (x)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3764
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3765
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3766 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3767 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
3768
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3773 <hr><h3><a name="pdf-math.asin"><code>math.asin (x)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3774
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3777 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
3778
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3779
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3780
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3781
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3782 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3783 <hr><h3><a name="pdf-math.atan"><code>math.atan (y [, x])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3784
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3785
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3786 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3787
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3788 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
3789 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
3790 quadrant of the result.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3791 (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
3792
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3793
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3794 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3795 The default value for <code>x</code> is 1,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3796 so that the call <code>math.atan(y)</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3797 returns the arc tangent of <code>y</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3798
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3799
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3800
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3801
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3802 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3803 <hr><h3><a name="pdf-math.ceil"><code>math.ceil (x)</code></a></h3>
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3806 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3807 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
3808
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3809
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3810
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3811
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3812 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3813 <hr><h3><a name="pdf-math.cos"><code>math.cos (x)</code></a></h3>
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 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
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3821
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3822 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3823 <hr><h3><a name="pdf-math.deg"><code>math.deg (x)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3824
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3827 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
3828
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3829
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3830
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3831
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3832 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3833 <hr><h3><a name="pdf-math.exp"><code>math.exp (x)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3834
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3835
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3836 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3837 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
3838 (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
3839
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3840
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3841
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3842
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3843 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3844 <hr><h3><a name="pdf-math.floor"><code>math.floor (x)</code></a></h3>
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3847 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3848 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
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-math.fmod"><code>math.fmod (x, y)</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 remainder of the division of <code>x</code> by <code>y</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3859 that rounds the quotient towards zero. (integer/float)
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-math.huge"><code>math.huge</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 The float value <code>HUGE_VAL</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3870 a value larger than any other numerical value.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3875 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3876 <hr><h3><a name="pdf-math.log"><code>math.log (x [, base])</code></a></h3>
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3879 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3880 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
3881 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
3882 (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
3883
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3884
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3885
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3886
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3887 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3888 <hr><h3><a name="pdf-math.max"><code>math.max (x, &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
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3892 Returns the argument with the maximum value,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3893 according to the Lua operator <code>&lt;</code>. (integer/float)
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3897
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3898 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3899 <hr><h3><a name="pdf-math.maxinteger"><code>math.maxinteger</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3900 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
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3905 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3906 <hr><h3><a name="pdf-math.min"><code>math.min (x, &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
3907
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3908
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3909 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3910 Returns the argument with the minimum value,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3911 according to the Lua operator <code>&lt;</code>. (integer/float)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3912
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3913
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3916 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3917 <hr><h3><a name="pdf-math.mininteger"><code>math.mininteger</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3918 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
3919
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3920
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3921
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3922
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3923 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3924 <hr><h3><a name="pdf-math.modf"><code>math.modf (x)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3925
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3926
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3927 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3928 Returns the integral part of <code>x</code> and the fractional part of <code>x</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3929 Its second result is always a float.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3930
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3931
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3932
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3933
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3934 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3935 <hr><h3><a name="pdf-math.pi"><code>math.pi</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3936
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3937
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3938 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3939 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
3940
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3941
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3942
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3945 <hr><h3><a name="pdf-math.rad"><code>math.rad (x)</code></a></h3>
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3948 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3949 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
3950
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3951
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3952
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3953
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3954 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3955 <hr><h3><a name="pdf-math.random"><code>math.random ([m [, n]])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3956
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3957
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3958 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3959 When called without arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3960 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
3961 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
3962 When called with two integers <code>m</code> and <code>n</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3963 <code>math.random</code> returns a pseudo-random integer
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3964 with uniform distribution in the range <em>[m, n]</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3965 (The value <em>m-n</em> cannot be negative and must fit in a Lua integer.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3966 The call <code>math.random(n)</code> is equivalent to <code>math.random(1,n)</code>.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3969 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3970 This function is an interface to the underling
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3971 pseudo-random generator function provided by C.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3972 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
3973
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3974
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3975
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3978 <hr><h3><a name="pdf-math.randomseed"><code>math.randomseed (x)</code></a></h3>
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3981 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3982 Sets <code>x</code> as the "seed"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3983 for the pseudo-random generator:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3984 equal seeds produce equal sequences of numbers.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3985
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3986
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3987
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3988
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3989 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3990 <hr><h3><a name="pdf-math.sin"><code>math.sin (x)</code></a></h3>
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3994 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
3995
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
3999 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4000 <hr><h3><a name="pdf-math.sqrt"><code>math.sqrt (x)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4001
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4004 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
4005 (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
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-math.tan"><code>math.tan (x)</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 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
4016
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4017
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4018
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4019
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4020 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4021 <hr><h3><a name="pdf-math.tointeger"><code>math.tointeger (x)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4022
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4023
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4024 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4025 If the value <code>x</code> is convertible to an integer,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4026 returns that integer.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4027 Otherwise, returns <b>nil</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4028
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4029
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 <hr><h3><a name="pdf-math.type"><code>math.type (x)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4034
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4035
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4036 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4037 Returns "<code>integer</code>" if <code>x</code> is an integer,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4038 "<code>float</code>" if it is a float,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4039 or <b>nil</b> if <code>x</code> is not a number.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4040
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4041
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4042
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4043
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4044 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4045 <hr><h3><a name="pdf-math.ult"><code>math.ult (m, n)</code></a></h3>
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 Returns a boolean,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4050 true if integer <code>m</code> is below integer <code>n</code> when
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4051 they are compared as unsigned integers.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4052
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4053
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4054
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 <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
4060
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4061 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4062 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
4063 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
4064 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
4065 default output file,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4066 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
4067 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
4068
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4069
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4070 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4071 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
4072 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
4073 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
4074 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
4075 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
4076
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4077
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4078 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4079 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
4080 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
4081 <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
4082 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
4083
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4084
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4085 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4086 Unless otherwise stated,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4087 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
4088 (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
4089 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
4090 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
4091 On non-POSIX systems,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4092 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
4093 in case of errors
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4094 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
4095 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
4096
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4097
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4098 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4099 <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
4100
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4101
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4102 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4103 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
4104 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
4105
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4106
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4107
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4108
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4109 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4110 <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
4111
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4112
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4113 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4114 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
4115
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4116
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4117
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4118
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4119 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4120 <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
4121
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4122
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4123 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4124 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
4125 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
4126 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
4127 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
4128 When called without parameters,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4129 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
4130
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4131
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4132 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4133 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
4134 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
4135
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4136
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4137
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4138
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4139 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4140 <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
4141
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4142
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4143 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4144 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
4145 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
4146 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
4147 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
4148 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
4149
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4150
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4151 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4152 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
4153 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
4154 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
4155 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
4156
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4157
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4158 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4159 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
4160 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
4161
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4162
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4163
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4166 <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
4167
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4168
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4169 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4170 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
4171 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
4172 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
4173 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
4174
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4175
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4176 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4177 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
4178
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4179 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4180 <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
4181 <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
4182 <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
4183 <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
4184 <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
4185 <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
4186 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
4187 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4188 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
4189 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
4190
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4191
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4192
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4193
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4194 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4195 <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
4196
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4197
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4198 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4199 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
4200
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4201
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4202
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4203
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4204 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4205 <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
4206
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4207
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4208 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4209 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
4210 on all platforms.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4211
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4214 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
4215 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
4216 (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
4217 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
4218 (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
4219
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4220
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4223 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4224 <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
4225
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4226
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4227 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4228 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
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4232
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4233 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4234 <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
4235
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4236
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4237 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4238 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
4239 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
4240 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
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4244
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4245 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4246 <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
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 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
4251 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
4252 <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
4253 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
4254
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4255
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4256
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4259 <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
4260
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4261
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4262 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4263 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
4264
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4268 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4269 <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
4270
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4271
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4272 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4273 Closes <code>file</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4274 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
4275 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
4276 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
4277
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4278
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4279 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4280 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
4281 <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
4282 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
4283
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4284
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4285
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4286
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4287 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4288 <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
4289
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4290
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4291 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4292 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
4293
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4296
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4297 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4298 <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
4299
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4300
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4301 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4302 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
4303 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
4304 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
4305 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
4306 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
4307 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
4308
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4309 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4310 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
4311 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4312 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
4313 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
4314 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
4315 when the loop ends.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4316
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4317
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4318 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4319 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
4320 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
4321
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4322
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4323
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4324
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4325 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4326 <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
4327
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4328
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4329 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4330 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
4331 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
4332 For each format,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4333 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
4334 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
4335 (In this latter case,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4336 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
4337 When called without formats,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4338 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
4339 (see below).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4340
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4341
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4342 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4343 The available formats are
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4344
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4345 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4346
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4347 <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
4348 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
4349 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
4350 (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
4351 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
4352 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
4353 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
4354 (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
4355 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
4356 </li>
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 <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
4359 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
4360 </li>
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 <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
4363 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
4364 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
4365 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4366
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4367 <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
4368 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
4369 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
4370 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
4371 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4372
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4373 <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
4374 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
4375 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
4376 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4377
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4378 <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
4379 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
4380 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
4381 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
4382 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
4383 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
4384 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4385
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4386 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4387 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
4388
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4389
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4390
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4391
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4392 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4393 <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
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4397 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
4398 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
4399 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
4400 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
4401
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4402 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4403 <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
4404 <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
4405 <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
4406 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4407 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
4408 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
4409 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
4410 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
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4414 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
4415 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
4416 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
4417 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
4418 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
4419 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
4420 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
4421 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
4422
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4423
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4424
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4425
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4426 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4427 <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
4428
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4429
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4430 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4431 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
4432 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
4433
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4434 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4435
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4436 <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
4437 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
4438 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4439
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4440 <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
4441 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
4442 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
4443 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
4444 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4445
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4446 <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
4447 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
4448 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
4449 (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
4450 </li>
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 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4453 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
4454 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
4455 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
4456
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
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4461 <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
4462
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4465 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
4466 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
4467
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4468
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4469 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4470 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
4471 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
4472
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4473
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4474
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4475
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
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 <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
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 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
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4486 <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
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4490 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
4491 used by the program.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4492
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4493
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4494
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4495
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4496 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4497 <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
4498
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4499
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4500 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4501 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
4502 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
4503
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4504
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4505 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4506 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
4507 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
4508 (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
4509 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
4510
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4511
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4512 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4513 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
4514 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
4515 After this optional character,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4516 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
4517 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
4518 <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
4519 <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
4520 <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
4521 <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
4522 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
4523 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
4524 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
4525
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4526
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4527 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4528 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
4529 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
4530 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
4531
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4532
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4533 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4534 When called without arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4535 <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
4536 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
4537 (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
4538
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4539
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4540 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4541 On non-POSIX systems,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4542 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
4543 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
4544
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4545
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4546
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4547
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4548 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4549 <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
4550
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4551
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4552 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4553 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
4554 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
4555 (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
4556 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
4557 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
4558
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4559
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4560
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4561
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4562 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4563 <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
4564
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4565
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4566 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4567 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
4568 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
4569 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
4570 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
4571 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
4572 After this first result
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4573 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
4574 as follows:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4575
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4576 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4577
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4578 <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
4579 the command terminated normally;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4580 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
4581 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4582
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4583 <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
4584 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
4585 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
4586 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4587
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4588 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4589
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4590 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4591 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
4592 <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
4593
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4594
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4595
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4596
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4597 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4598 <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
4599
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4600
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4601 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4602 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
4603 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
4604 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
4605 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
4606 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
4607 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
4608 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
4609 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
4610
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4611
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4612 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4613 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
4614 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
4615
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4616
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4617
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4618
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4619 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4620 <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
4621
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4622
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4623 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4624 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
4625 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
4626
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4627
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4628
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4629
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4630 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4631 <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
4632
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4633
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4634 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4635 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
4636 with the given name.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4637 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
4638 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
4639
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4640
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4641
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4642
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4643 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4644 <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
4645
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4646
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4647 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4648 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
4649 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
4650 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
4651
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4652
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4653
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4654
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4655 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4656 <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
4657
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4658
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4659 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4660 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
4661 <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
4662 <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
4663 <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
4664 <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
4665 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
4666 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
4667 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
4668
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4669
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4670 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4671 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
4672 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
4673 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
4674 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
4675
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4676
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4677 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4678 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
4679 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
4680 for the given category.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4681
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4682
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4683 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4684 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
4685 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
4686
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4687
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4688
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4689
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4690 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4691 <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
4692
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4693
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4694 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4695 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
4696 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
4697 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
4698 and may have fields
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4699 <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
4700 <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
4701 <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
4702 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
4703 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
4704
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4705
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4706 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4707 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
4708 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
4709 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
4710 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
4711 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
4712 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
4713 <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
4714
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4715
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4716
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4717
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4718 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4719 <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
4720
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4721
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4722 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4723 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
4724 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
4725 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
4726 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
4727
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4728
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4729 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4730 On POSIX systems,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4731 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
4732 to avoid security risks.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4733 (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
4734 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
4735 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
4736 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
4737
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4738
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4739 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4740 When possible,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4741 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
4742 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
4743
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4744
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4745
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4746
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4747
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4748
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4749
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4750 <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
4751
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4752 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4753 This library provides
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4754 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
4755 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
4756 Several of its functions
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4757 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
4758 (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
4759 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
4760 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
4761 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
4762 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
4763 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
4764
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4765
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4766 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4767 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
4768 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
4769 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
4770 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
4771 thread to operate over.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4772 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
4773
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4774
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4775 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4776 <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
4777
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4778
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4779 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4780 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
4781 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
4782 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
4783 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
4784 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
4785 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
4786 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
4787
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4788
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4789 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4790 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
4791 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
4792
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4793
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4794
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4795
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4796 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4797 <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
4798
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4799
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4800 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4801 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
4802 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
4803 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
4804 (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
4805
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4806
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4807
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4808
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4809 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4810 <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
4811
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4812
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4813 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4814 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
4815 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
4816 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
4817 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
4818 of the given thread:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4819 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
4820 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
4821 (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
4822 and so on.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4823 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
4824 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
4825
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4826
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4827 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4828 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
4829 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
4830 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
4831 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
4832 If present,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4833 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
4834 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
4835 If present,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4836 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
4837 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
4838 valid lines.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4839
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4840
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4841 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4842 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
4843 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
4844 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
4845 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
4846 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
4847 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
4848
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4849
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4850
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4851
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4852 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4853 <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
4854
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4855
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4856 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4857 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
4858 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
4859 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
4860 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
4861
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4862
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4863 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4864 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
4865 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
4866 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
4867 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
4868 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
4869 -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
4870 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
4871 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
4872 (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
4873
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4874
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4875 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4876 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
4877 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
4878 (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
4879 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
4880
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4881
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4882 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4883 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
4884 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
4885
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4886
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4887
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4888
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4889 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4890 <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
4891
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4892
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4893 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4894 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
4895 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
4896
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4897
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4898
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4899
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4900 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4901 <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
4902
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4903
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4904 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4905 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
4906
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4907
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4908
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4909
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4910 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4911 <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
4912
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4913
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4914 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4915 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
4916 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
4917 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
4918
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4919
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4920 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4921 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
4922 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
4923 (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
4924
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4925
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4926
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4927
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4928 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4929 <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
4930
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4931
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4932 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4933 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
4934 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
4935 returns <b>nil</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4936
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4937
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4938
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4939
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4940 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4941 <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
4942
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4943
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4944 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4945 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
4946 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
4947 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
4948 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
4949 with the given meaning:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4950
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4951 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4952 <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
4953 <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
4954 <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
4955 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4956 Moreover,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4957 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
4958 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
4959
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4960
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4961 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4962 When called without arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4963 <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
4964
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4965
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4966 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4967 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
4968 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
4969 <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
4970 <code>"return"</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4971 <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
4972 For line events,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4973 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
4974 Inside a hook,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4975 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
4976 the running function
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4977 (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
4978 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
4979
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4980
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4981
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4982
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4983 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4984 <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
4985
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4986
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4987 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4988 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
4989 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
4990 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
4991 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
4992 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
4993 (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
4994 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
4995
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4996
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4997 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
4998 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
4999 variable indices and names.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5000
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5001
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5002
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5003
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5004 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5005 <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
5006
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5007
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5008 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5009 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
5010 (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
5011 Returns <code>value</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5012
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5013
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5014
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5015
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5016 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5017 <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
5018
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5019
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5020 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5021 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
5022 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
5023 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
5024 with the given index.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5025 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
5026
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5027
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5028
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5029
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5030 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5031 <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
5032
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5033
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5034 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5035 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
5036 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
5037 <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
5038
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5039
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5040 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5041 Returns <code>udata</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5042
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5043
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5044
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5045
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5046 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5047 <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
5048
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5049
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5050 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5051 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
5052 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
5053 Otherwise,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5054 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
5055 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
5056 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
5057 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
5058 to start the traceback
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5059 (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
5060
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5061
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5062
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5063
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5064 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5065 <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
5066
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5067
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5068 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5069 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
5070 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
5071 from the given function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5072
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5073
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5074 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5075 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
5076 closures share upvalues.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5077 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
5078 (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
5079 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
5080
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5081
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5082
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5083
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5084 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5085 <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
5086
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5087
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5088 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5089 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
5090 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
5091
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5092
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5093
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5094
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5095
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5096
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5097
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5098 <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
5099
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5100 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5101 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
5102 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
5103 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
5104 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
5105 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
5106 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
5107 The standalone interpreter includes
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5108 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
5109 Its usage is:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5110
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5111 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5112 lua [options] [script [args]]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5113 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5114 The options are:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5115
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5116 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5117 <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
5118 <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
5119 <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
5120 <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
5121 <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
5122 <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
5123 <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
5124 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5125 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
5126 When called without arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5127 <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
5128 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
5129 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
5130
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5131
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5132 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5133 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
5134 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
5135 (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
5136 before running any argument.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5137 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
5138 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
5139 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
5140
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5141
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5142 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5143 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
5144 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
5145 Lua also ignores
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5146 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
5147 setting the values of
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5148 <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
5149 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
5150
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5151
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5152 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5153 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
5154 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
5155
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5156 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5157 $ 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
5158 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5159 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
5160 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
5161 (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
5162
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5163
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5164 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5165 Before running any code,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5166 <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
5167 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
5168 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
5169 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
5170 and so on.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5171 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
5172 (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
5173 go to negative indices.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5174 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
5175
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5176 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5177 $ 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
5178 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5179 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
5180
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5181 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5182 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
5183 [0] = "b.lua",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5184 [1] = "t1", [2] = "t2" }
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5185 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5186 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
5187 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
5188 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
5189 For instance, the call
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5190
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5191 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5192 $ 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
5193 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5194 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
5195 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
5196 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
5197 <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
5198 (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
5199 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
5200
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5201
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5202 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5203 In interactive mode,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5204 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
5205 After reading a line,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5206 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
5207 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
5208 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
5209 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
5210 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
5211 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
5212
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5213
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5214 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5215 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
5216 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
5217 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
5218 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
5219 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
5220 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
5221 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
5222
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5223
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5224 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5225 When finishing normally,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5226 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
5227 (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
5228 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
5229 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
5230
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5231
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5232 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5233 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
5234 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
5235 the standalone interpreter skips
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5236 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
5237 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
5238 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
5239 as in
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5240
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5241 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5242 #!/usr/local/bin/lua
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5243 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5244 (Of course,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5245 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
5246 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
5247 then
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5248
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5249 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5250 #!/usr/bin/env lua
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5251 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5252 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
5253
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5254
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5255
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5256 <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
5257
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5258 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5259 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
5260 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
5261 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
5262 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
5263 However,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5264 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
5265
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5266
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5267 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5268 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
5269 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
5270 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
5271 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
5272 Therefore,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5273 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
5274 different Lua versions.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5275 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
5276 using a new version.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5277
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5278
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5279 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5280 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
5281 of precompiled chunks;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5282 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
5283
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5284
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5285 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5286 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
5287 change between versions.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5288
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5289
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5290
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5291 <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
5292 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5293
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5294 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5295 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
5296 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
5297 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
5298 some computations
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5299 (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
5300 can give different results.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5301
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5302
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5303 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5304 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
5305 (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
5306 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
5307 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
5308 (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
5309 for an occasional incompatibility;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5310 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
5311 For good programming,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5312 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
5313 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
5314 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5315
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5316 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5317 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
5318 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
5319 (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
5320 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
5321 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
5322 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
5323
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5324
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5325 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5326 (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
5327 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
5328 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
5329 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5330
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5331 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5332 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
5333 (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
5334 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5335
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5336 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5337
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5338
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5339
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5340
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5341 <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
5342 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5343
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5344 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5345 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
5346 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
5347 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
5348 (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
5349 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
5350 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5351
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5352 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5353 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
5354 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
5355 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5356
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5357 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5358 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
5359 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
5360 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5361
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5362 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5363 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
5364 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
5365 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5366
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5367 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5368 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
5369 <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
5370 <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
5371 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
5372 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
5373 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
5374 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
5375 For the other operations,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5376 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
5377 implement them in Lua.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5378 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5379
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5380 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5381 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
5382 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
5383 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
5384 (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
5385 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
5386 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
5387 (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
5388 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
5389 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5390
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5391 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5392
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5393
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5394
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5395
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5396 <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
5397
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5398
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5399 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5400
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5401 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5402 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
5403 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
5404 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
5405 Adapt your code accordingly.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5406 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5407
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5408 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5409 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
5410 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
5411 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5412
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5413 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5414 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
5415 (<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
5416 <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
5417 were deprecated.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5418 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
5419 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5420
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5421 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5422 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
5423 (<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
5424 were deprecated.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5425 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
5426 (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
5427 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5428
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5429 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5430
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5431
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5432
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5433
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5434 <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
5435
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5436 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5437 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
5438 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
5439 {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
5440 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
5441 (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
5442 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
5443 Name, Numeral,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5444 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
5445
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5446
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5447
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5448
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5449 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5450
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5451 chunk ::= block
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5452
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5453 block ::= {stat} [retstat]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5454
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5455 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
5456 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
5457 functioncall |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5458 label |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5459 <b>break</b> |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5460 <b>goto</b> Name |
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5461 <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
5462 <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
5463 <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
5464 <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
5465 <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
5466 <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
5467 <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
5468 <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
5469 <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
5470
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5471 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
5472
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5473 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
5474
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5475 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
5476
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5477 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
5478
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5479 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
5480
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5481 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
5482
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5483 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
5484
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5485 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
5486 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
5487
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5488 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
5489
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5490 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
5491
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
5492 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
5493
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5494 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
5495
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5496 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
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parents:
diff changeset
5497
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5498 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
5499
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5500 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
5501
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5502 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
5503
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5504 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
5505
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5506 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
5507
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5508 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
5509 &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
5510 &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
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parents:
diff changeset
5511 <b>and</b> | <b>or</b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
5512
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5513 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
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parents:
diff changeset
5514
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5515 </pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
5516
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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parents:
diff changeset
5517 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
5518
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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diff changeset
5519
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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5520
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
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5521
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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5522
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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5523
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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5524
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
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5525
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5526 <HR>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5527 <SMALL CLASS="footer">
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5528 Last update:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5529 Fri Jan 16 00:58:20 BRST 2015
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5530 </SMALL>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
5531 <!--
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
Franklin Schmidt <fschmidt@gmail.com>
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diff changeset
5532 Last change: minor edit
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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5533 -->
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual
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5534
372
f08cefa4594c start editing manual
Franklin Schmidt <fschmidt@gmail.com>
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diff changeset
5535 </div>
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
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diff changeset
5536
391
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom
Franklin Schmidt <fschmidt@gmail.com>
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diff changeset
5537 <% Html.simply_html_body_bottom() %>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom
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parents: 389
diff changeset
5538 </body>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom
Franklin Schmidt <fschmidt@gmail.com>
parents: 389
diff changeset
5539 </html>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom
Franklin Schmidt <fschmidt@gmail.com>
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diff changeset
5540 <%
386
db23f654f87d make all of website use luan
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diff changeset
5541 end