repo/luan: website/src/manual.html annotate

annotate website/src/manual.html @ 1485:6a24c8b33d6b

minor

author	Franklin Schmidt <fschmidt@gmail.com>
date	Fri, 01 May 2020 11:23:29 -0600
parents	56fb5cd8228d
children	d9a5405a3102

rev	line source
1216 5dbb552075ff doctype Franklin Schmidt <fschmidt@gmail.com> parents: 1195 diff changeset	1 <!doctype html>
391 2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 389 diff changeset	2 <html>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 389 diff changeset	3 <head>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 389 diff changeset	4 <title>Luan Reference Manual</title>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	5 <style>
1326 29d6d7d79c41 website - use relative paths Franklin Schmidt <fschmidt@gmail.com> parents: 1325 diff changeset	6 @import "site.css";
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	7 </style>
391 2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 389 diff changeset	8 </head>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 389 diff changeset	9 <body>
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 382 diff changeset	10
1326 29d6d7d79c41 website - use relative paths Franklin Schmidt <fschmidt@gmail.com> parents: 1325 diff changeset	11 <div small>
29d6d7d79c41 website - use relative paths Franklin Schmidt <fschmidt@gmail.com> parents: 1325 diff changeset	12 <a href=".">Luan</a>
29d6d7d79c41 website - use relative paths Franklin Schmidt <fschmidt@gmail.com> parents: 1325 diff changeset	13 / <a href="docs.html">Documentation</a>
29d6d7d79c41 website - use relative paths Franklin Schmidt <fschmidt@gmail.com> parents: 1325 diff changeset	14 </div>
372 f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	15
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	16 <h1><a href="manual.html">Luan Reference Manual</a></h1>
372 f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	17
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	18 <p small>
372 f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	19 Original copyright © 2015 Lua.org, PUC-Rio.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	20 Freely available under the terms of the
372 f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	21 <a href="http://www.lua.org/license.html">Lua license</a>.
f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	22 Modified for Luan.
f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	23 </p>
f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	24
f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	25 <hr/>
f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	26
f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	27 <h2>Contents</h2>
f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	28
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	29 <div contents><a href="#intro">Introduction</a></div>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	30
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	31 <div contents>
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	32 <a href="#basic">Basic Concepts</a>
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	33 <ul>
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	34 <li><a href="#types">Values and Types</a></li>
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	35 <li><a href="#env">Environments</a></li>
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	36 <li><a href="#error">Error Handling</a></li>
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	37 <li><a href="#meta">Metatables and Metamethods</a></li>
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	38 <li><a href="#gc">Garbage Collection</a></li>
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	39 </ul>
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	40 </div>
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	41
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	42 <div contents>
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	43 <a href="#lang">The Language</a>
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	44 <ul>
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	45 <li><a href="#lex">Lexical Conventions</a></li>
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	46 <li><a href="#vars">Variables</a></li>
389 497d4ef0a89f documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 387 diff changeset	47 <li>
497d4ef0a89f documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 387 diff changeset	48 <a href="#stmts">Statements</a>
497d4ef0a89f documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 387 diff changeset	49 <ul>
497d4ef0a89f documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 387 diff changeset	50 <li><a href="#blocks">Blocks</a></li>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	51 <li><a href="#chunks">Chunks</a></li>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	52 <li><a href="#assignment">Assignment</a></li>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	53 <li><a href="#control">Control Structures</a></li>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	54 <li><a href="#for">For Statement</a></li>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	55 <li><a href="#fn_stmt">Function Calls as Statements</a></li>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	56 <li><a href="#local_stmt">Local Declarations</a></li>
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	57 <li><a href="#template_stmt">Template Statements</a></li>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	58 </ul>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	59 </li>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	60 <li>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	61 <a href="#expressions">Expressions</a>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	62 <ul>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	63 <li><a href="#arithmetic">Arithmetic Operators</a></li>
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	64 <li><a href="#conversions">Coercions and Conversions</a></li>
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	65 <li><a href="#relational">Relational Operators</a></li>
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	66 <li><a href="#logical_ops">Logical Operators</a></li>
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	67 <li><a href="#concatenation">Concatenation</a></li>
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	68 <li><a href="#length">The Length Operator</a></li>
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	69 <li><a href="#precedence">Precedence</a></li>
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	70 <li><a href="#constructors">Table Constructors</a></li>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	71 <li><a href="#fn_calls">Function Calls</a></li>
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	72 <li><a href="#fn_def">Function Definitions</a></li>
389 497d4ef0a89f documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 387 diff changeset	73 </ul>
497d4ef0a89f documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 387 diff changeset	74 </li>
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	75 <li><a href="#visibility">Visibility Rules</a></li>
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	76 </ul>
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	77 </div>
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	78
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	79 <div contents>
468 9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	80 <a href="#libs">Standard Libraries</a>
9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	81 <ul>
9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	82 <li><a href="#default_lib">Default Environment</a></li>
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	83 <li><a href="#luan_lib">Basic Functions</a></li>
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	84 <li><a href="#package_lib">Modules</a></li>
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	85 <li><a href="#string_lib">String Manipulation</a></li>
567 6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	86 <li><a href="#binary_lib">Binary Manipulation</a></li>
565 22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	87 <li><a href="#table_lib">Table Manipulation</a></li>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	88 <li><a href="#number_lib">Number Manipulation</a></li>
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	89 <li><a href="#math_lib">Mathematical Functions</a></li>
468 9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	90 </ul>
9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	91 </div>
9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	92
372 f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	93 <hr/>
f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	94
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	95
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	96 <h2 heading><a name="intro" href="#intro">Introduction</a></h2>
372 f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	97
f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	98 <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>
f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	99
f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	100 <p>Luan is implemented in Java and is tightly coupled with Java. So it makes a great scripting language for Java programmers.</p>
f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	101
f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 371 diff changeset	102 <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>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	103
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	104
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	105 <h2 heading><a name="basic" href="#basic">Basic Concepts</a></h2>
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	106
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	107 <p>This section describes the basic concepts of the language.</p>
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	108
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	109 <h3 heading><a name="types" href="#types">Values and Types</a></h3>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	110
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	111 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	112 Luan is a <em>dynamically typed language</em>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	113 This means that
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	114 variables do not have types; only values do.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	115 There are no type definitions in the language.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	116 All values carry their own type.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	117
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	118
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	119 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	120 All values in Luan are <em>first-class values</em>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	121 This means that all values can be stored in variables,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	122 passed as arguments to other functions, and returned as results.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	123
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	124
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	125 <p>
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	126 There are eight basic types in Luan:
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	127 <em>nil</em>, <em>boolean</em>, <em>number</em>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	128 <em>string</em>, <em>binary</em>, <em>function</em>, <em>java</em>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	129 and <em>table</em>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	130 <em>Nil</em> is the type of the value <b>nil</b>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	131 whose main property is to be different from any other value;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	132 it usually represents the absence of a useful value.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	133 <em>Nil</em> is implemented as the Java value <em>null</em>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	134 <em>Boolean</em> is the type of the values <b>false</b> and <b>true</b>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	135 <em>Boolean</em> is implemented as the Java class <em>Boolean</em>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	136 <em>Number</em> represents both
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	137 integer numbers and real (floating-point) numbers.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	138 <em>Number</em> is implemented as the Java class <em>Number</em>. Any Java subclass of <em>Number</em> is allowed and this is invisible to the Luan user. Operations on numbers follow the same rules of
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	139 the underlying Java implementation.
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	140
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	141 <em>String</em> is implemented as the Java class <em>String</em>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	142 <em>Binary</em> is implemented as the Java type <em>byte[]</em>.
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	143
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	144
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	145 <p>
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	146 Luan can call (and manipulate) functions written in Luan and
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	147 functions written in Java (see <a href="#fn_calls">Function Calls</a>).
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	148 Both are represented by the type <em>function</em>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	149
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	150
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	151 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	152 The type <em>java</em> is provided to allow arbitrary Java objects to
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	153 be stored in Luan variables.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	154 A <em>java</em> value is a Java object that isn't one of the standard Luan types.
513 0dfc01d8d42d rename type "userdata" to "java" Franklin Schmidt <fschmidt@gmail.com> parents: 512 diff changeset	155 Java values have no predefined operations in Luan,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	156 except assignment and identity test.
513 0dfc01d8d42d rename type "userdata" to "java" Franklin Schmidt <fschmidt@gmail.com> parents: 512 diff changeset	157 Java values are useful when Java access is enabled in Luan
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	158
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	159
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	160
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	161 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	162 The type <em>table</em> implements associative arrays,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	163 that is, arrays that can be indexed not only with numbers,
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	164 but with any Luan value except <b>nil</b>.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	165 Tables can be <em>heterogeneous</em>;
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	166 that is, they can contain values of all types (except <b>nil</b>).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	167 Any key with value <b>nil</b> is not considered part of the table.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	168 Conversely, any key that is not part of a table has
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	169 an associated value <b>nil</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	170
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	171
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	172 <p>
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	173 Tables are the sole data-structuring mechanism in Luan;
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	174 they can be used to represent ordinary arrays, sequences,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	175 symbol tables, sets, records, graphs, trees, etc.
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	176 To represent records, Luan uses the field name as an index.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	177 The language supports this representation by
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	178 providing <code>a.name</code> as syntactic sugar for <code>a["name"]</code>.
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	179 There are several convenient ways to create tables in Luan
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	180 (see <a href="#constructors">Table Constructors</a>).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	181
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	182
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	183 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	184 We use the term <em>sequence</em> to denote a table where
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	185 the set of all positive numeric keys is equal to {1..<em>n</em>}
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	186 for some non-negative integer <em>n</em>,
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	187 which is called the length of the sequence (see <a href="#length">The Length Operator</a>).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	188
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	189
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	190 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	191 Like indices,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	192 the values of table fields can be of any type.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	193 In particular,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	194 because functions are first-class values,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	195 table fields can contain functions.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	196 Thus tables can also carry <em>methods</em> (see <a href="#fn_def">Function Definitions</a>).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	197
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	198
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	199 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	200 The indexing of tables follows
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	201 the definition of raw equality in the language.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	202 The expressions <code>a[i]</code> and <code>a[j]</code>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	203 denote the same table element
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	204 if and only if <code>i</code> and <code>j</code> are raw equal
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	205 (that is, equal without metamethods).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	206 In particular, floats with integral values
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	207 are equal to their respective integers
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	208 (e.g., <code>1.0 == 1</code>).
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	209
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	210
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	211 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	212 Luan values are <em>objects</em>:
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	213 variables do not actually <em>contain</em> values,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	214 only <em>references</em> to them.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	215 Assignment, parameter passing, and function returns
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	216 always manipulate references to values;
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	217 these operations do not imply any kind of copy.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	218
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	219
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	220 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	221 The library function <a href="#Luan.type"><code>Luan.type</code></a> returns a string describing the type
478 eb6d90fb0b5c documentation Franklin Schmidt <fschmidt@gmail.com> parents: 476 diff changeset	222 of a given value.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	223
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	224
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	225
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	226
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	227
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	228 <h3 heading><a name="env" href="#env">Environments</a></h3>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	229
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	230 <p>
1353 8d95711f6615 replace java() with require "java" Franklin Schmidt <fschmidt@gmail.com> parents: 1342 diff changeset	231 The environment of a chunk starts with only one local variable: <code><a href="#require">require</a></code>. This function is used to load and access libraries and other modules. All other variables must be added to the environment using <a href="http://localhost:8080/manual.html#local_stmt">local declarations</a>.
512 d96944467ffc update documentation for luan changes Franklin Schmidt <fschmidt@gmail.com> parents: 505 diff changeset	232
d96944467ffc update documentation for luan changes Franklin Schmidt <fschmidt@gmail.com> parents: 505 diff changeset	233 <p>
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	234 As will be discussed in <a href="#vars">Variables</a> and <a href=#assignment">Assignment</a>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	235 any reference to a free name
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	236 (that is, a name not bound to any declaration) <code>var</code>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	237 can be syntactically translated to <code>_ENV.var</code> if <code>_ENV</code> is defined.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	238
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	239
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	240 <h3 heading><a name="error" href="#error">Error Handling</a></h3>
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	241
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	242 <p>
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	243 Luan code can explicitly generate an error by calling the
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	244 <a href="#Luan.error"><code>error</code></a> function.
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	245 If you need to catch errors in Luan,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	246 you can use <a href="#Luan.pcall"><code>pcall</code></a> or <a href="#Luan.try"><code>try</code></a>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	247 to call a given function in <em>protected mode</em>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	248
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	249
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	250 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	251 Whenever there is an error,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	252 an <em>error table</em>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	253 is propagated with information about the error.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	254 See <a href="#Luan.new_error"><code>Luan.new_error</code></a>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	255
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	256
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	257
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	258 <h3 heading><a name="meta" href="#meta">Metatables and Metamethods</a></h3>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	259
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	260 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	261 Every table in Luan can have a <em>metatable</em>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	262 This <em>metatable</em> is an ordinary Luan table
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	263 that defines the behavior of the original value
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	264 under certain special operations.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	265 You can change several aspects of the behavior
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	266 of operations over a value by setting specific fields in its metatable.
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	267 For instance, when a table is the operand of an addition,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	268 Luan checks for a function in the field "<code>__add</code>" of the table's metatable.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	269 If it finds one,
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	270 Luan calls this function to perform the addition.
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	271
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	272
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	273 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	274 The keys in a metatable are derived from the <em>event</em> names;
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	275 the corresponding values are called <ii>metamethods</em>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	276 In the previous example, the event is <code>"add"</code>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	277 and the metamethod is the function that performs the addition.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	278
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	279
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	280 <p>
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	281 You can query the metatable of any table
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	282 using the <a href="#Luan.get_metatable"><code>get_metatable</code></a> function.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	283
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	284
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	285 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	286 You can replace the metatable of tables
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	287 using the <a href="#Luan.set_metatable"><code>set_metatable</code></a> function.
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	288
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	289
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	290 <p>
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	291 A metatable controls how a table behaves in
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	292 arithmetic operations, bitwise operations,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	293 order comparisons, concatenation, length operation, calls, and indexing.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	294
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	295
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	296 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	297 A detailed list of events controlled by metatables is given next.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	298 Each operation is identified by its corresponding event name.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	299 The key for each event is a string with its name prefixed by
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	300 two underscores, '<code>__</code>';
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	301 for instance, the key for operation "add" is the
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	302 string "<code>__add</code>".
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	303 Note that queries for metamethods are always raw;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	304 the access to a metamethod does not invoke other metamethods.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	305 You can emulate how Luan queries a metamethod for an object <code>obj</code>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	306 with the following code:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	307
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	308 <pre>
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	309 raw_get(get_metatable(obj) or {}, "__" .. event_name)
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	310 </pre>
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	311
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	312 <p>
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	313 Here are the events:
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	314
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	315 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	316
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	317 <li><p><b>"add": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	318 the <code>+</code> operation.
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	319
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	320 If any operand for an addition is a table,
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	321 Luan will try to call a metamethod.
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	322 First, Luan will check the first operand (even if it is valid).
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	323 If that operand does not define a metamethod for the "<code>__add</code>" event,
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	324 then Luan will check the second operand.
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	325 If Luan can find a metamethod,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	326 it calls the metamethod with the two operands as arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	327 and the result of the call
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	328 (adjusted to one value)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	329 is the result of the operation.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	330 Otherwise,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	331 it raises an error.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	332 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	333
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	334 <li><p><b>"sub": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	335 the <code>-</code> operation.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	336
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	337 Behavior similar to the "add" operation.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	338 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	339
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	340 <li><p><b>"mul": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	341 the <code>*</code> operation.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	342
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	343 Behavior similar to the "add" operation.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	344 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	345
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	346 <li><p><b>"div": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	347 the <code>/</code> operation.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	348
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	349 Behavior similar to the "add" operation.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	350 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	351
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	352 <li><p><b>"mod": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	353 the <code>%</code> operation.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	354
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	355 Behavior similar to the "add" operation.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	356 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	357
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	358 <li><p><b>"pow": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	359 the <code>^</code> (exponentiation) operation.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	360
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	361 Behavior similar to the "add" operation.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	362 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	363
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	364 <li><p><b>"unm": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	365 the <code>-</code> (unary minus) operation.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	366
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	367 Behavior similar to the "add" operation.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	368 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	369
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	370 <li><p><b>"concat": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	371 the <code>..</code> (concatenation) operation.
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	372
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	373 Behavior similar to the "add" operation.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	374 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	375
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	376 <li><p><b>"len": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	377 the <code>#</code> (length) operation.
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	378
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	379 If there is a metamethod,
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	380 Luan calls it with the object as argument,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	381 and the result of the call
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	382 (always adjusted to one value)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	383 is the result of the operation.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	384 If there is no metamethod but the object is a table,
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	385 then Luan uses the table length operation (see <a href="#length">The Length Operator</a>).
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	386 Otherwise, Luan raises an error.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	387 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	388
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	389 <li><p><b>"eq": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	390 the <code>==</code> (equal) operation.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	391
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	392 Behavior similar to the "add" operation,
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	393 except that Luan will try a metamethod only when the values
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	394 being compared are both tables
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	395 and they are not primitively equal.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	396 The result of the call is always converted to a boolean.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	397 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	398
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	399 <li><p><b>"lt": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	400 the <code><</code> (less than) operation.
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	401
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	402 Behavior similar to the "add" operation.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	403 The result of the call is always converted to a boolean.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	404 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	405
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	406 <li><p><b>"le": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	407 the <code><=</code> (less equal) operation.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	408
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	409 Unlike other operations,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	410 The less-equal operation can use two different events.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	411 First, Luan looks for the "<code>__le</code>" metamethod in both operands,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	412 like in the "lt" operation.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	413 If it cannot find such a metamethod,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	414 then it will try the "<code>__lt</code>" event,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	415 assuming that <code>a <= b</code> is equivalent to <code>not (b < a)</code>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	416 As with the other comparison operators,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	417 the result is always a boolean.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	418 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	419
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	420 <li><p><b>"index": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	421 The indexing access <code>table[key]</code>.
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	422
571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	423 This event happens
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	424 when <code>key</code> is not present in <code>table</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	425 The metamethod is looked up in <code>table</code>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	426
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	427
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	428 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	429 Despite the name,
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	430 the metamethod for this event can be any type.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	431 If it is a function,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	432 it is called with <code>table</code> and <code>key</code> as arguments.
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	433 Otherwise
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	434 the final result is the result of indexing this metamethod object with <code>key</code>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	435 (This indexing is regular, not raw,
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	436 and therefore can trigger another metamethod if the metamethod object is a table.)
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	437 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	438
502 d3183a330ff5 improve the __index metamethod to work with any type; Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	439 <li><p><b>"new_index": </b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	440 The indexing assignment <code>table[key] = value</code>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	441
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	442 Like the index event,
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	443 this event happens when
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	444 when <code>key</code> is not present in <code>table</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	445 The metamethod is looked up in <code>table</code>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	446
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	447
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	448 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	449 Like with indexing,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	450 the metamethod for this event can be either a function or a table.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	451 If it is a function,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	452 it is called with <code>table</code>, <code>key</code>, and <code>value</code> as arguments.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	453 If it is a table,
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	454 Luan does an indexing assignment to this table with the same key and value.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	455 (This assignment is regular, not raw,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	456 and therefore can trigger another metamethod.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	457
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	458
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	459 <p>
428 df95199ca4c0 rename __newindex to __new_index Franklin Schmidt <fschmidt@gmail.com> parents: 418 diff changeset	460 Whenever there is a "new_index" metamethod,
373 571057b1666b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	461 Luan does not perform the primitive assignment.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	462 (If necessary,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	463 the metamethod itself can call <a href="#Luan.raw_set"><code>raw_set</code></a>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	464 to do the assignment.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	465 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	466
1272 95f6540b27f9 add __gc to docs Franklin Schmidt <fschmidt@gmail.com> parents: 1257 diff changeset	467 <li><p><b>"gc":</b>
95f6540b27f9 add __gc to docs Franklin Schmidt <fschmidt@gmail.com> parents: 1257 diff changeset	468 This is when a table is garbage collected. When the table's <a href="https://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#finalize()">finalize</a> method is called by the Java garbage collector, if there is a "<code>__gc</code>" metamethod then it is called with the table as a parameter.
95f6540b27f9 add __gc to docs Franklin Schmidt <fschmidt@gmail.com> parents: 1257 diff changeset	469
95f6540b27f9 add __gc to docs Franklin Schmidt <fschmidt@gmail.com> parents: 1257 diff changeset	470 </li>
95f6540b27f9 add __gc to docs Franklin Schmidt <fschmidt@gmail.com> parents: 1257 diff changeset	471
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	472 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	473
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	474
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	475
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	476
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	477 <h3 heading><a name="gc" href="#gc">Garbage Collection</a></h3>
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	478
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	479 <p>
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	480 Luan uses Java's garbage collection.
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	481
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	482
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	483
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	484
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	485
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	486 <h2 heading><a name="lang" href="#lang">The Language</a></h2>
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	487
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	488 <p>
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	489 This section describes the lexis, the syntax, and the semantics of Luan.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	490 In other words,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	491 this section describes
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	492 which tokens are valid,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	493 how they can be combined,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	494 and what their combinations mean.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	495
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	496
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	497 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	498 Language constructs will be explained using the usual extended BNF notation,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	499 in which
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	500 {<em>a</em>} means 0 or more <em>a</em>'s, and
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	501 [<em>a</em>] means an optional <em>a</em>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	502 Non-terminals are shown like non-terminal,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	503 keywords are shown like <b>kword</b>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	504 and other terminal symbols are shown like ‘<b>=</b>’.
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	505 The complete syntax of Luan can be found in <a href="#9">§9</a>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	506 at the end of this manual.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	507
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	508
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	509
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	510 <h3 heading><a name="lex" href="#lex">Lexical Conventions</a></h3>
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	511
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	512 <p>
6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	513 Luan ignores spaces and comments
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	514 between lexical elements (tokens),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	515 except as delimiters between names and keywords.
685 1e4b0bc0202d update documentation Franklin Schmidt <fschmidt@gmail.com> parents: 642 diff changeset	516 Luan considers the end of a line to be the end of a statement. This catches errors and encourages readability. If you want to continue a statement on another line, you can use a backslash followed by a newline which will be treated as white space.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	517
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	518 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	519 <em>Names</em>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	520 (also called <em>identifiers</em>)
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	521 in Luan can be any string of letters,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	522 digits, and underscores,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	523 not beginning with a digit.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	524 Identifiers are used to name variables, table fields, and labels.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	525
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	526
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	527 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	528 The following <em>keywords</em> are reserved
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	529 and cannot be used as names:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	530
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	531
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	532 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	533 and break do else elseif end
1092 a26fbde7ee28 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 1090 diff changeset	534 end_do end_for end_function end_if end_while
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	535 false for function goto if in
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	536 local nil not or repeat return
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	537 then true until while
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	538 </pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	539
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	540 <p>
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	541 Luan is a case-sensitive language:
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	542 <code>and</code> is a reserved word, but <code>And</code> and <code>AND</code>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	543 are two different, valid names.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	544
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	545
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	546 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	547 The following strings denote other tokens:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	548
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	549 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	550 + - * / % ^ #
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	551 & ~ \| << >> //
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	552 == ~= <= >= < > =
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	553 ( ) { } [ ] ::
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	554 ; : , . .. ...
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	555 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	556
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	557 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	558 <em>Literal strings</em>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	559 can be delimited by matching single or double quotes,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	560 and can contain the following C-like escape sequences:
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	561 '<code>\a</code>' (bell),
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	562 '<code>\b</code>' (backspace),
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	563 '<code>\f</code>' (form feed),
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	564 '<code>\n</code>' (newline),
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	565 '<code>\r</code>' (carriage return),
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	566 '<code>\t</code>' (horizontal tab),
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	567 '<code>\v</code>' (vertical tab),
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	568 '<code>\\</code>' (backslash),
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	569 '<code>\"</code>' (quotation mark [double quote]),
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	570 and '<code>\'</code>' (apostrophe [single quote]).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	571 A backslash followed by a real newline
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	572 results in a newline in the string.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	573 The escape sequence '<code>\z</code>' skips the following span
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	574 of white-space characters,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	575 including line breaks;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	576 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	577 into multiple lines without adding the newlines and spaces
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	578 into the string contents.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	579
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	580
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	581 <p>
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	582 Luan can specify any character in a literal string by its numerical value.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	583 This can be done
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	584 with the escape sequence <code>\x<em>XX</em></code>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	585 where <em>XX</em> is a sequence of exactly two hexadecimal digits,
793 60661a8e738c minor Franklin Schmidt <fschmidt@gmail.com> parents: 702 diff changeset	586 or with the escape sequence <code>\u<em>XXXX</em></code>,
60661a8e738c minor Franklin Schmidt <fschmidt@gmail.com> parents: 702 diff changeset	587 where <em>XXXX</em> is a sequence of exactly four hexadecimal digits,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	588 or with the escape sequence <code>\<em>ddd</em></code>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	589 where <em>ddd</em> is a sequence of up to three decimal digits.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	590 (Note that if a decimal escape sequence is to be followed by a digit,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	591 it must be expressed using exactly three digits.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	592
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	593
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	594 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	595 Literal strings can also be defined using a long format
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	596 enclosed by <em>long brackets</em>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	597 We define an <em>opening long bracket of level <em>n</em></em> as an opening
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	598 square bracket followed by <em>n</em> equal signs followed by another
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	599 opening square bracket.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	600 So, an opening long bracket of level 0 is written as <code>[[</code>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	601 an opening long bracket of level 1 is written as <code>[=[</code>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	602 and so on.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	603 A <em>closing long bracket</em> is defined similarly;
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	604 for instance,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	605 a closing long bracket of level 4 is written as <code>]====]</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	606 A <em>long literal</em> starts with an opening long bracket of any level and
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	607 ends at the first closing long bracket of the same level.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	608 It can contain any text except a closing bracket of the same level.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	609 Literals in this bracketed form can run for several lines,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	610 do not interpret any escape sequences,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	611 and ignore long brackets of any other level.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	612 Any kind of end-of-line sequence
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	613 (carriage return, newline, carriage return followed by newline,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	614 or newline followed by carriage return)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	615 is converted to a simple newline.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	616
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	617
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	618 <p>
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	619 Any character in a literal string not
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	620 explicitly affected by the previous rules represents itself.
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	621 However, Luan opens files for parsing in text mode,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	622 and the system file functions may have problems with
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	623 some control characters.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	624 So, it is safer to represent
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	625 non-text data as a quoted literal with
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	626 explicit escape sequences for non-text characters.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	627
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	628
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	629 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	630 For convenience,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	631 when the opening long bracket is immediately followed by a newline,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	632 the newline is not included in the string.
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	633 As an example
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	634 the five literal strings below denote the same string:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	635
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	636 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	637 a = 'alo\n123"'
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	638 a = "alo\n123\""
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	639 a = '\97lo\10\04923"'
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	640 a = [[alo
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	641 123"]]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	642 a = [==[
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	643 alo
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	644 123"]==]
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	645 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	646
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	647 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	648 A <em>numerical constant</em> (or <em>numeral</em>)
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	649 can be written with an optional fractional part
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	650 and an optional decimal exponent,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	651 marked by a letter '<code>e</code>' or '<code>E</code>'.
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	652 Luan also accepts hexadecimal constants,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	653 which start with <code>0x</code> or <code>0X</code>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	654 Hexadecimal constants also accept an optional fractional part
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	655 plus an optional binary exponent,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	656 marked by a letter '<code>p</code>' or '<code>P</code>'.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	657 A numeric constant with a fractional dot or an exponent
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	658 denotes a float;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	659 otherwise it denotes an integer.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	660 Examples of valid integer constants are
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	661
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	662 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	663 3 345 0xff 0xBEBADA
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	664 </pre>
382 8557581740db added tutorial Franklin Schmidt <fschmidt@gmail.com> parents: 380 diff changeset	665
8557581740db added tutorial Franklin Schmidt <fschmidt@gmail.com> parents: 380 diff changeset	666 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	667 Examples of valid float constants are
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	668
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	669 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	670 3.0 3.1416 314.16e-2 0.31416E1 34e1
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	671 0x0.1E 0xA23p-4 0X1.921FB54442D18P+1
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	672 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	673
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	674 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	675 A <em>comment</em> starts with a double hyphen (<code>--</code>)
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	676 anywhere outside a string.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	677 If the text immediately after <code>--</code> is not an opening long bracket,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	678 the comment is a <em>short comment</em>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	679 which runs until the end of the line.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	680 Otherwise, it is a <em>long comment</em>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	681 which runs until the corresponding closing long bracket.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	682 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	683
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	684
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	685
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	686
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	687
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	688 <h3 heading><a name="vars" href="#vars">Variables</a></h3>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	689
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	690 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	691 Variables are places that store values.
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	692 There are three kinds of variables in Luan:
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	693 global variables, local variables, and table fields.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	694
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	695 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	696 A single name can denote a global variable or a local variable
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	697 (or a function's formal parameter,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	698 which is a particular kind of local variable):
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	699
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	700 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	701 var ::= Name
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	702 </pre>
382 8557581740db added tutorial Franklin Schmidt <fschmidt@gmail.com> parents: 380 diff changeset	703
8557581740db added tutorial Franklin Schmidt <fschmidt@gmail.com> parents: 380 diff changeset	704 <p>
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	705 Name denotes identifiers, as defined in <a href="#lex">Lexical Conventions</a>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	706
512 d96944467ffc update documentation for luan changes Franklin Schmidt <fschmidt@gmail.com> parents: 505 diff changeset	707 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	708 Local variables are <em>lexically scoped</em>:
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	709 local variables can be freely accessed by functions
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	710 defined inside their scope (see <a href="#visibility">Visibility Rules</a>).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	711
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	712
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	713 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	714 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 Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	715
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	716 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	717 Square brackets are used to index a table:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	718
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	719 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	720 var ::= prefixexp ‘<b>[</b>’ exp ‘<b>]</b>’
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	721 </pre>
382 8557581740db added tutorial Franklin Schmidt <fschmidt@gmail.com> parents: 380 diff changeset	722
8557581740db added tutorial Franklin Schmidt <fschmidt@gmail.com> parents: 380 diff changeset	723 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	724 The meaning of accesses to table fields can be changed via metatables.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	725 An access to an indexed variable <code>t[i]</code> is equivalent to
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	726 a call <code>gettable_event(t,i)</code>.
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	727 (See <a href="#meta">Metatables and Metamethods</a> for a complete description of the
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	728 <code>gettable_event</code> function.
380 6c6c3537035e work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 373 diff changeset	729 This function is not defined or callable in Luan.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	730 We use it here only for explanatory purposes.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	731
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	732
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	733 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	734 The syntax <code>var.Name</code> is just syntactic sugar for
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	735 <code>var["Name"]</code>:
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	736
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	737 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	738 var ::= prefixexp ‘<b>.</b>’ Name
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	739 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	740
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	741 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	742 Global variables are not available by default. To enable global variable, you must define <code>_ENV</code> as a local variable whose value is a table. If <code>_ENV</code> is not defined, then an unrecognized variable name will produce a compile error. If <code>_ENV</code> is defined then an access to an unrecognized variable name will be consider a global variable. So then an acces to global variable <code>x</code>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	743 is equivalent to <code>_ENV.x</code>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	744 Due to the way that chunks are compiled,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	745 <code>_ENV</code> is never a global name (see <a href="#env">Environments</a>).
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	746
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	747
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	748
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	749
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	750
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	751 <h3 heading><a name="stmts" href="#stmts">Statements</a></h3>
389 497d4ef0a89f documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 387 diff changeset	752
497d4ef0a89f documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 387 diff changeset	753 <p>
497d4ef0a89f documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 387 diff changeset	754 Luan supports an almost conventional set of statements,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	755 similar to those in Pascal or C.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	756 This set includes
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	757 assignments, control structures, function calls,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	758 and variable declarations.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	759
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	760
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	761
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	762 <h4 heading><a name="blocks" href="#blocks">Blocks</a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	763
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	764 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	765 A block is a list of statements,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	766 which are executed sequentially:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	767
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	768 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	769 block ::= {stat}
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	770 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	771
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	772 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	773 Luan has <em>empty statements</em>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	774 that allow you to separate statements with semicolons,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	775 start a block with a semicolon
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	776 or write two semicolons in sequence:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	777
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	778 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	779 stat ::= ‘<b>;</b>’
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	780 </pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	781
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	782 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	783 A block can be explicitly delimited to produce a single statement:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	784
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	785 <pre>
1092 a26fbde7ee28 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 1090 diff changeset	786 stat ::= <b>do</b> block end_do
a26fbde7ee28 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 1090 diff changeset	787 end_do ::= <b>end_do</b> \| <b>end</b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	788 </pre>
389 497d4ef0a89f documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 387 diff changeset	789
497d4ef0a89f documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 387 diff changeset	790 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	791 Explicit blocks are useful
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	792 to control the scope of variable declarations.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	793 Explicit blocks are also sometimes used to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	794 add a <b>return</b> statement in the middle
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	795 of another block (see <a href="#control">Control Structures</a>).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	796
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	797
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	798
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	799
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	800
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	801 <h4 heading><a name="chunks" href="#chunks">Chunks</a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	802
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	803 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	804 The unit of compilation of Luan is called a <em>chunk</em>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	805 Syntactically,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	806 a chunk is simply a block:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	807
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	808 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	809 chunk ::= block
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	810 </pre>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	811
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	812 <p>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	813 Luan handles a chunk as the body of an anonymous function
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	814 with a variable number of arguments
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	815 (see <a href="#fn_def">Function Definitions</a>).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	816 As such, chunks can define local variables,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	817 receive arguments, and return values.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	818
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	819
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	820 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	821 A chunk can be stored in a file or in a string inside the host program.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	822 To execute a chunk,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	823 Luan first <em>loads</em> it,
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	824 compiling the chunk's code,
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	825 and then Luan executes the compiled code.
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	826
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	827
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	828
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	829
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	830
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	831 <h4 heading><a name="assignment" href="#assignment">Assignment</a></h4>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	832
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	833 <p>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	834 Luan allows multiple assignments.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	835 Therefore, the syntax for assignment
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	836 defines a list of variables on the left side
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	837 and a list of expressions on the right side.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	838 The elements in both lists are separated by commas:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	839
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	840 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	841 stat ::= varlist ‘<b>=</b>’ explist
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	842 varlist ::= var {‘<b>,</b>’ var}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	843 explist ::= exp {‘<b>,</b>’ exp}
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	844 </pre>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	845
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	846 <p>
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	847 Expressions are discussed in <a href="#expressions">Expressions</a>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	848
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	849
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	850 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	851 Before the assignment,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	852 the list of values is <em>adjusted</em> to the length of
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	853 the list of variables.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	854 If there are more values than needed,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	855 the excess values are thrown away.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	856 If there are fewer values than needed,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	857 the list is extended with as many <b>nil</b>'s as needed.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	858 If the list of expressions ends with a function call,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	859 then all values returned by that call enter the list of values,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	860 before the adjustment
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	861 (except when the call is enclosed in parentheses; see <a href="#expressions">Expressions</a>).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	862
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	863
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	864 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	865 The assignment statement first evaluates all its expressions
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	866 and only then the assignments are performed.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	867 Thus the code
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	868
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	869 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	870 i = 3
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	871 i, a[i] = i+1, 20
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	872 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	873
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	874 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	875 sets <code>a[3]</code> to 20, without affecting <code>a[4]</code>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	876 because the <code>i</code> in <code>a[i]</code> is evaluated (to 3)
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	877 before it is assigned 4.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	878 Similarly, the line
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	879
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	880 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	881 x, y = y, x
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	882 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	883
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	884 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	885 exchanges the values of <code>x</code> and <code>y</code>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	886 and
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	887
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	888 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	889 x, y, z = y, z, x
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	890 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	891
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	892 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	893 cyclically permutes the values of <code>x</code>, <code>y</code>, and <code>z</code>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	894
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	895
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	896 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	897 The meaning of assignments to global variables
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	898 and table fields can be changed via metatables.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	899 An assignment to an indexed variable <code>t[i] = val</code> is equivalent to
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	900 <code>settable_event(t,i,val)</code>.
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	901 (See <a href="#meta">Metatables and Metamethods</a> for a complete description of the
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	902 <code>settable_event</code> function.
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	903 This function is not defined or callable in Luan.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	904 We use it here only for explanatory purposes.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	905
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	906
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	907 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	908 An assignment to a global name <code>x = val</code>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	909 is equivalent to the assignment
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	910 <code>_ENV.x = val</code> (see <a href="#env">Environments</a>).
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	911 Global names are only available when <code>_ENV</code> is defined.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	912
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	913
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	914
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	915 <h4 heading><a name="control" href="#control">Control Structures</a></h4>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	916
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	917 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	918 The control structures
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	919 <b>if</b>, <b>while</b>, and <b>repeat</b> have the usual meaning and
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	920 familiar syntax:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	921
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	922 <pre>
1092 a26fbde7ee28 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 1090 diff changeset	923 stat ::= <b>while</b> exp <b>do</b> block end_while
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	924 stat ::= <b>repeat</b> block <b>until</b> exp
1092 a26fbde7ee28 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 1090 diff changeset	925 stat ::= <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] end_if
a26fbde7ee28 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 1090 diff changeset	926 end_while ::= <b>end_while</b> \| <b>end</b>
a26fbde7ee28 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 1090 diff changeset	927 end_if ::= <b>end_if</b> \| <b>end</b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	928 </pre>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	929
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	930 <p>
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	931 Luan also has a <b>for</b> statement (see <a href="#for">For Statement</a>).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	932
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	933
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	934 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	935 The condition expression of a
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	936 control structure must be a boolean.
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	937 Any other value type will produce an error.
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	938 This helps catch errors and makes code more readable.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	939
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	940
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	941 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	942 In the <b>repeat</b>–<b>until</b> loop,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	943 the inner block does not end at the <b>until</b> keyword,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	944 but only after the condition.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	945 So, the condition can refer to local variables
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	946 declared inside the loop block.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	947
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	948
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	949 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	950 The <b>break</b> statement terminates the execution of a
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	951 <b>while</b>, <b>repeat</b>, or <b>for</b> loop,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	952 skipping to the next statement after the loop:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	953
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	954
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	955 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	956 stat ::= <b>break</b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	957 </pre>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	958
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	959 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	960 A <b>break</b> ends the innermost enclosing loop.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	961
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	962
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	963 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	964 The <b>return</b> statement is used to return values
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	965 from a function or a chunk
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	966 (which is an anonymous function).
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	967
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	968 Functions can return more than one value,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	969 so the syntax for the <b>return</b> statement is
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	970
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	971 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	972 stat ::= <b>return</b> [explist] [‘<b>;</b>’]
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	973 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	974
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	975
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	976
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	977
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	978 <h4 heading><a name="for" href="#for">For Statement</a></h4>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	979
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	980 <p>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	981 The <b>for</b> statement works over functions,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	982 called <em>iterators</em>.
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	983 On each iteration, the iterator function is called to produce a new value,
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	984 stopping when this new value is <b>nil</b>.
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	985 The <b>for</b> loop has the following syntax:
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	986
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	987 <pre>
1092 a26fbde7ee28 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 1090 diff changeset	988 stat ::= <b>for</b> namelist <b>in</b> exp <b>do</b> block end_for
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	989 namelist ::= Name {‘<b>,</b>’ Name}
1092 a26fbde7ee28 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 1090 diff changeset	990 end_for ::= <b>end_for</b> \| <b>end</b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	991 </pre>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	992
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	993 <p>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	994 A <b>for</b> statement like
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	995
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	996 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	997 for <em>var_1</em>, ···, <em>var_n</em> in <em>exp</em> do <em>block</em> end
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	998 </pre>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	999
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1000 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1001 is equivalent to the code:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1002
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1003 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1004 do
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1005 local <em>f</em> = <em>exp</em>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1006 while true do
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1007 local <em>var_1</em>, ···, <em>var_n</em> = <em>f</em>()
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1008 if <em>var_1</em> == nil then break end
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1009 <em>block</em>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1010 end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1011 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1012 </pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1013
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1014 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1015 Note the following:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1016
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1017 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1018
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1019 <li>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1020 <code><em>exp</em></code> is evaluated only once.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1021 Its result is an <em>iterator</em> function.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1022 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1023
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1024 <li>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1025 <code><em>f</em></code> is an invisible variable.
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1026 The name is here for explanatory purposes only.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1027 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1028
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1029 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1030 You can use <b>break</b> to exit a <b>for</b> loop.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1031 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1032
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1033 <li>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1034 The loop variables <code><em>var_i</em></code> are local to the loop;
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1035 you cannot use their values after the <b>for</b> ends.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1036 If you need these values,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1037 then assign them to other variables before breaking or exiting the loop.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1038 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1039
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1040 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1041
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1042
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1043
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1044
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1045 <h4 heading><a name="fn_stmt" href="#fn_stmt">Function Calls as Statements</a></h4>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1046
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1047 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1048 To allow possible side-effects,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1049 function calls can be executed as statements:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1050
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1051 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1052 stat ::= functioncall
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1053 </pre>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1054
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1055 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1056 In this case, all returned values are thrown away.
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1057 Function calls are explained in <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	1058
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1059
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1060
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1061 <h4 heading><a name="local_stmt" href="#local_stmt">Local Declarations</a></h4>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1062
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1063 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1064 Local variables can be declared anywhere inside a block.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1065 The declaration can include an initial assignment:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1066
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1067 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1068 stat ::= <b>local</b> namelist [‘<b>=</b>’ explist]
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1069 </pre>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1070
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1071 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1072 If present, an initial assignment has the same semantics
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1073 of a multiple assignment (see <a href="#assignment">Assignment</a>).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1074 Otherwise, all variables 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	1075
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1076
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1077 <p>
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1078 A chunk is also a block (see <a href="#chunks">Chunks</a>),
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1079 and so local variables can be declared in a chunk outside any explicit block.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1080
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1081
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1082 <p>
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1083 The visibility rules for local variables are explained in <a href="#visibility">Visibility Rules</a>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1084
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1085
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1086 <h4 heading><a name="template_stmt" href="#template_stmt">Template Statements</a></h4>
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1087
1384 f5368cd8c056 remove template expressions and String.concat Franklin Schmidt <fschmidt@gmail.com> parents: 1373 diff changeset	1088 <p>Template statements provide the full equivalent of <a href="http://en.wikipedia.org/wiki/JavaServer_Pages">JSP</a> but in a general way. Template statements write to standard output. For example:</p>
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1089
1325 28c1fc6d9d29 website - make docs html Franklin Schmidt <fschmidt@gmail.com> parents: 1324 diff changeset	1090 <pre>
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1091 local name = "Bob"
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1092 %>
469 85467f95ab13 minor Franklin Schmidt <fschmidt@gmail.com> parents: 468 diff changeset	1093 Hello <%= name %>!
85467f95ab13 minor Franklin Schmidt <fschmidt@gmail.com> parents: 468 diff changeset	1094 Bye <%= name %>.
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1095 <%
1325 28c1fc6d9d29 website - make docs html Franklin Schmidt <fschmidt@gmail.com> parents: 1324 diff changeset	1096 </pre>
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1097
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1098 <p>is equivalent to the code:</p>
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1099
1325 28c1fc6d9d29 website - make docs html Franklin Schmidt <fschmidt@gmail.com> parents: 1324 diff changeset	1100 <pre>
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1101 local name = "Bob"
1384 f5368cd8c056 remove template expressions and String.concat Franklin Schmidt <fschmidt@gmail.com> parents: 1373 diff changeset	1102 require("luan:Io.luan").stdout.write( "Hello ", name , "!\nBye ", name , ".\n" )
1325 28c1fc6d9d29 website - make docs html Franklin Schmidt <fschmidt@gmail.com> parents: 1324 diff changeset	1103 </pre>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1104
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1105
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1106
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1107 <h3 heading><a name="expressions" href="#expressions">Expressions</a></h3>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1108
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1109 <p>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1110 The basic expressions in Luan are the following:
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1111
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1112 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1113 exp ::= prefixexp
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1114 exp ::= <b>nil</b> \| <b>false</b> \| <b>true</b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1115 exp ::= Numeral
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1116 exp ::= LiteralString
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1117 exp ::= functiondef
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1118 exp ::= tableconstructor
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1119 exp ::= ‘<b>...</b>’
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1120 exp ::= exp binop exp
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1121 exp ::= unop exp
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1122 prefixexp ::= var \| functioncall \| ‘<b>(</b>’ exp ‘<b>)</b>’
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1123 </pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1124
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1125 <p>
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1126 Numerals and literal strings are explained in <a href="#lex">Lexical Conventions</a>;
eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1127 variables are explained in <a href="#vars">Variables</a>;
eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1128 function definitions are explained in <a href="#fn_def">Function Definitions</a>;
eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1129 function calls are explained in <a href="#fn_calls">Function Calls</a>;
eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1130 table constructors are explained in <a href="#constructors">Table Constructors</a>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1131 Vararg expressions,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1132 denoted by three dots ('<code>...</code>'), can only be used when
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1133 directly inside a vararg function;
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1134 they are explained in <a href="#fn_def">Function Definitions</a>.
eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1135
eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1136
eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1137 <p>
eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1138 Binary operators comprise arithmetic operators (see <a href="#arithmetic">Arithmetic Operators</a>),
eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1139 relational operators (see <a href="#relational">Relational Operators</a>), logical operators (see <a href="#logical_ops">Logical Operators</a>),
eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1140 and the concatenation operator (see <a href="#concatenation">Concatenation</a>).
eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1141 Unary operators comprise the unary minus (see <a href="#arithmetic">Arithmetic Operators</a>),
eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1142 the unary logical <b>not</b> (see <a href="#logical_ops">Logical Operators</a>),
eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1143 and the unary <em>length operator</em> (see <a href="#length">The Length Operator</a>).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1144
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1145
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1146 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1147 Both function calls and vararg expressions can result in multiple values.
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1148 If a function call is used as a statement (see <a href="#fn_stmt">Function Calls as Statements</a>),
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1149 then its return list is adjusted to zero elements,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1150 thus discarding all returned values.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1151 If an expression is used as the last (or the only) element
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1152 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	1153 then no adjustment is made
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1154 (unless the 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	1155 In all other contexts,
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1156 Luan adjusts the result list to one element,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1157 either discarding all values except the first one
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1158 or adding a single <b>nil</b> if there are no values.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1159
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1160
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1161 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1162 Here are some examples:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1163
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1164 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1165 f() -- adjusted to 0 results
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1166 g(f(), x) -- f() is adjusted to 1 result
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1167 g(x, f()) -- g gets x plus all results from f()
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1168 a,b,c = f(), x -- f() is adjusted to 1 result (c gets nil)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1169 a,b = ... -- a gets the first vararg parameter, b gets
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1170 -- the second (both a and b can get nil if there
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1171 -- is no corresponding vararg parameter)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1172
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1173 a,b,c = x, f() -- f() is adjusted to 2 results
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1174 a,b,c = f() -- f() is adjusted to 3 results
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1175 return f() -- returns all results from f()
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1176 return ... -- returns all received vararg parameters
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1177 return x,y,f() -- returns x, y, and all results from f()
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1178 {f()} -- creates a list with all results from f()
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1179 {...} -- creates a list with all vararg parameters
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1180 {f(), nil} -- f() is adjusted to 1 result
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1181 </pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> 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 Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1184 Any expression enclosed in parentheses always results in only one value.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1185 Thus,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1186 <code>(f(x,y,z))</code> is always a single value,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1187 even if <code>f</code> returns several values.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1188 (The value of <code>(f(x,y,z))</code> is the first value returned by <code>f</code>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1189 or <b>nil</b> if <code>f</code> does not return any values.)
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1190
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1191
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1192
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1193 <h4 heading><a name="arithmetic" href="#arithmetic">Arithmetic Operators</a></h4>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1194
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1195 <p>
a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1196 Luan supports the following arithmetic operators:
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1197
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1198 <ul>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1199 <li><b><code>+</code>: </b>addition</li>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1200 <li><b><code>-</code>: </b>subtraction</li>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1201 <li><b><code>*</code>: </b>multiplication</li>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1202 <li><b><code>/</code>: </b>division</li>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1203 <li><b><code>%</code>: </b>modulo</li>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1204 <li><b><code>^</code>: </b>exponentiation</li>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1205 <li><b><code>-</code>: </b>unary minus</li>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1206 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1207
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1208 <p>
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1209 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 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1210
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1211 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1212 Modulo is defined as the remainder of a division
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1213 that rounds the quotient towards minus infinite (floor division).
395 a7cb58532846 work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 391 diff changeset	1214 (The Java modulo operator is not used.)
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1215
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1216
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1217
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1218 <h4 heading><a name="conversions" href="#conversions">Coercions and Conversions</a></h4>
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1219
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1220 <p>
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1221 Luan generally avoids automatic conversions.
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1222 String concatenation automatically converts all of its arguments to strings.
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1223
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1224 <p>
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	1225 Luan provides library functions for explicit type conversions.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1226
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1227
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1228
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1229
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1230 <h4 heading><a name="relational" href="#relational">Relational Operators</a></h4>
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1231
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1232 <p>
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1233 Luan supports the following relational operators:
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1234
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1235 <ul>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1236 <li><b><code>==</code>: </b>equality</li>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1237 <li><b><code>~=</code>: </b>inequality</li>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1238 <li><b><code><</code>: </b>less than</li>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1239 <li><b><code>></code>: </b>greater than</li>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1240 <li><b><code><=</code>: </b>less or equal</li>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1241 <li><b><code>>=</code>: </b>greater or equal</li>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1242 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1243 These operators always result in <b>false</b> or <b>true</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1244
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1245
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1246 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1247 Equality (<code>==</code>) first compares the type of its operands.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1248 If the types are different, then the result is <b>false</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1249 Otherwise, the values of the operands are compared.
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1250 Strings, numbers, and binary values are compared in the obvious way (by value).
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1251
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1252 <p>
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1253 Tables
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1254 are compared by reference:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1255 two objects are considered equal only if they are the same object.
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1256 Every time you create a new table,
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1257 it is different from any previously existing table.
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1258 Closures are also compared by reference.
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1259
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1260 <p>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1261 You can change the way that Luan compares tables
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1262 by using the "eq" metamethod (see <a href="#meta">Metatables and Metamethods</a>).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1263
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1264 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1265 Java values are compared for equality with the Java <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#equals(java.lang.Object)"><code>equals</code></a> method.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1266
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1267 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1268 Equality comparisons do not convert strings to numbers
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1269 or vice versa.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1270 Thus, <code>"0"==0</code> evaluates to <b>false</b>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1271 and <code>t[0]</code> and <code>t["0"]</code> denote different
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1272 entries in a table.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1273
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1274
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1275 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1276 The operator <code>~=</code> is exactly the negation of equality (<code>==</code>).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1277
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1278
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1279 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1280 The order operators work as follows.
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1281
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1282 If both arguments are numbers,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1283 then they are compared following
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1284 the usual rule for binary operations.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1285 Otherwise, if both arguments are strings,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1286 then their values are compared according to the current locale.
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1287 Otherwise, Luan tries to call the "lt" or the "le"
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1288 metamethod (see <a href="#meta">Metatables and Metamethods</a>).
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1289 A comparison <code>a > b</code> is translated to <code>b < a</code>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1290 and <code>a >= b</code> is translated to <code>b <= a</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1291
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1292
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1293
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1294
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1295
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1296 <h4 heading><a name="logical_ops" href="#logical_ops">Logical Operators</a></h4>
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1297
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1298 <p>
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1299 The logical operators in Luan are
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1300 <b>and</b>, <b>or</b>, and <b>not</b>.
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1301 The <b>and</b> and <b>or</b> operators consider both <b>false</b> and <b>nil</b> as false
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1302 and anything else as true.
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1303 Like the control structures (see <a href="#control">Control Structures</a>),
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1304 the <b>not</b> operator requires a boolean value.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1305
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1306 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1307 The negation operator <b>not</b> always returns <b>false</b> or <b>true</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1308 The conjunction operator <b>and</b> returns its first argument
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1309 if this value 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	1310 otherwise, <b>and</b> returns its second argument.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1311 The disjunction operator <b>or</b> returns its first argument
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1312 if this value is different from <b>nil</b> and <b>false</b>;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1313 otherwise, <b>or</b> returns its second argument.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1314 Both <b>and</b> and <b>or</b> use short-circuit evaluation;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1315 that is,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1316 the second operand is evaluated only if necessary.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1317 Here are some examples:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1318
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1319 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1320 10 or 20 --> 10
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1321 10 or error() --> 10
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1322 nil or "a" --> "a"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1323 nil and 10 --> nil
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1324 false and error() --> false
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1325 false and nil --> false
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1326 false or nil --> nil
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1327 10 and 20 --> 20
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1328 </pre>
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1329
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1330 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1331 (In this manual,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1332 <code>--></code> indicates the result of the preceding expression.)
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1333
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1334
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1335
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1336 <h4 heading><a name="concatenation" href="#concatenation">Concatenation</a></h4>
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1337
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1338 <p>
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1339 The string concatenation operator in Luan is
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1340 denoted by two dots ('<code>..</code>').
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1341 All operands are converted to strings.
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1342
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1343
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1344
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1345 <h4 heading><a name="length" href="#length">The Length Operator</a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1346
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1347 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1348 The length operator is denoted by the unary prefix operator <code>#</code>.
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1349 The length of a string is its number of characters.
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1350 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	1351
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1352
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1353 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1354 A program can modify the behavior of the length operator for
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1355 any table through the <code>__len</code> metamethod (see <a href="#meta">Metatables and Metamethods</a>).
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1356
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1357
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1358 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1359 Unless a <code>__len</code> metamethod is given,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1360 the length of a table <code>t</code> is defined
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1361 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	1362 that is,
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1363 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	1364 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	1365 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	1366 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	1367
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1368 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1369 {10, 20, nil, 40}
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1370 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1371
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1372 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1373 has a length of <code>2</code>, because that is the last key in sequence.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1374
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1375
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1376
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1377
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1378
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1379 <h4 heading><a name="precedence" href="#precedence">Precedence</a></h4>
396 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 <p>
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1382 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	1383 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	1384
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1385 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1386 or
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1387 and
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 + -
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1391 * / %
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1392 unary operators (not # -)
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1393 ^
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1394 </pre>
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1395
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1396 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1397 As usual,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1398 you can use parentheses to change the precedences of an expression.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1399 The concatenation ('<code>..</code>') and exponentiation ('<code>^</code>')
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1400 operators are right associative.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1401 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	1402
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1403
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1404
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1405
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1406
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1407 <h4 heading><a name="constructors" href="#constructors">Table Constructors</a></h4>
396 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>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1410 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	1411 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	1412 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	1413 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	1414 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	1415
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1416 <pre>
604 b73f005f3735 table constructor now uses end_of_line as a delimiter Franklin Schmidt <fschmidt@gmail.com> parents: 589 diff changeset	1417 tableconstructor ::= ‘<b>{</b>’ fieldlist ‘<b>}</b>’
b73f005f3735 table constructor now uses end_of_line as a delimiter Franklin Schmidt <fschmidt@gmail.com> parents: 589 diff changeset	1418 fieldlist ::= [field] {fieldsep [field]}
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1419 field ::= ‘<b>[</b>’ exp ‘<b>]</b>’ ‘<b>=</b>’ exp \| Name ‘<b>=</b>’ exp \| exp
604 b73f005f3735 table constructor now uses end_of_line as a delimiter Franklin Schmidt <fschmidt@gmail.com> parents: 589 diff changeset	1420 fieldsep ::= ‘<b>,</b>’ \| ‘<b>;</b>’ \| <b>end_of_line</b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1421 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1422
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1423 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1424 Each field of the form <code>[exp1] = exp2</code> adds to the new table an entry
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1425 with key <code>exp1</code> and value <code>exp2</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1426 A field of the form <code>name = exp</code> is equivalent to
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1427 <code>["name"] = exp</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1428 Finally, fields of the form <code>exp</code> are equivalent to
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1429 <code>[i] = exp</code>, where <code>i</code> are consecutive integers
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1430 starting with 1.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1431 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	1432 For example,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1433
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1434 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1435 a = { [f(1)] = g; "x", "y"; x = 1, f(x), [30] = 23; 45 }
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1436 </pre>
396 ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1437
ba8b0aae6453 work on manual; Franklin Schmidt <fschmidt@gmail.com> parents: 395 diff changeset	1438 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1439 is equivalent to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1440
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1441 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1442 do
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1443 local t = {}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1444 t[f(1)] = g
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1445 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	1446 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	1447 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	1448 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	1449 t[30] = 23
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1450 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	1451 a = t
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1452 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1453 </pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1454
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1455 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1456 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	1457 (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	1458
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1459
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1460 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1461 If the last field in the list has the form <code>exp</code>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1462 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	1463 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	1464 (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	1465
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1466
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1467 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1468 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	1469 as a convenience for machine-generated code.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1470
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1471
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1472
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1473
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1474
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1475 <h4 heading><a name="fn_calls" href="#fn_calls">Function Calls</a></h4>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1476
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1477 <p>
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1478 A function call in Luan has the following syntax:
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1479
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1480 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1481 functioncall ::= prefixexp args
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1482 </pre>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1483
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1484 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1485 In a function call,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1486 first prefixexp and args are evaluated.
685 1e4b0bc0202d update documentation Franklin Schmidt <fschmidt@gmail.com> parents: 642 diff changeset	1487 The value of prefixexp must have type <em>function</em>.
1e4b0bc0202d update documentation Franklin Schmidt <fschmidt@gmail.com> parents: 642 diff changeset	1488 This function is called
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1489 with the given arguments.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1490
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 Arguments have the following syntax:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1494
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1495 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1496 args ::= ‘<b>(</b>’ [explist] ‘<b>)</b>’
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1497 args ::= tableconstructor
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1498 args ::= LiteralString
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1499 </pre>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1500
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1501 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1502 All argument expressions are evaluated before the call.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1503 A call of the form <code>f{<em>fields</em>}</code> is
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1504 syntactic sugar for <code>f({<em>fields</em>})</code>;
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1505 that is, the argument list is a single new table.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1506 A call of the form <code>f'<em>string</em>'</code>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1507 (or <code>f"<em>string</em>"</code> or <code>f[[<em>string</em>]]</code>)
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1508 is syntactic sugar for <code>f('<em>string</em>')</code>;
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1509 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	1510
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1511
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1512
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1513
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1514 <h4 heading><a name="fn_def" href="#fn_def">Function Definitions</a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1515
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1516 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1517 The syntax for function definition is
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1518
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1519 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1520 functiondef ::= <b>function</b> funcbody
1092 a26fbde7ee28 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 1090 diff changeset	1521 funcbody ::= ‘<b>(</b>’ [parlist] ‘<b>)</b>’ block end_function
a26fbde7ee28 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 1090 diff changeset	1522 end_function ::= <b>end_function</b> \| <b>end</b>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1523 </pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1524
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1525 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1526 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	1527
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1528 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1529 stat ::= <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	1530 stat ::= <b>local</b> <b>function</b> Name funcbody
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1531 funcname ::= Name {‘<b>.</b>’ Name} [‘<b>:</b>’ Name]
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1532 </pre>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1533
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1534 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1535 The statement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1536
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1537 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1538 function f () <em>body</em> end
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1539 </pre>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1540
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1541 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1542 translates to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1543
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1544 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1545 f = function () <em>body</em> end
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1546 </pre>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1547
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1548 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1549 The statement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1550
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1551 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1552 function t.a.b.c.f () <em>body</em> end
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1553 </pre>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1554
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1555 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1556 translates to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1557
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1558 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1559 t.a.b.c.f = function () <em>body</em> end
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1560 </pre>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1561
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1562 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1563 The statement
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1564
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1565 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1566 local function f () <em>body</em> end
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1567 </pre>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1568
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1569 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1570 translates to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1571
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1572 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1573 local f; f = function () <em>body</em> end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1574 </pre>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1575
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1576 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1577 not to
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1578
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1579 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1580 local f = function () <em>body</em> end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1581 </pre>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1582
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1583 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1584 (This only makes a difference when the body of the function
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1585 contains references to <code>f</code>.)
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1586
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1587
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1588 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1589 A function definition is an executable expression,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1590 whose value has type <em>function</em>.
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1591 When Luan precompiles a chunk,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1592 all its function bodies are precompiled too.
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1593 Then, whenever Luan executes the function definition,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1594 the function is <em>instantiated</em> (or <em>closed</em>).
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1595 This function instance (or <em>closure</em>)
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1596 is the final value of the expression.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1597
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1598
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1599 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1600 Parameters act as local variables that are
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1601 initialized with the argument values:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1602
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1603 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1604 parlist ::= namelist [‘<b>,</b>’ ‘<b>...</b>’] \| ‘<b>...</b>’
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1605 </pre>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> 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 When a function is called,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1609 the list of arguments is adjusted to
1090 616761e0b9f6 update documentation for last change Franklin Schmidt <fschmidt@gmail.com> parents: 799 diff changeset	1610 the length of the list of parameters if the list is too short,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1611 unless the function is a <em>vararg function</em>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1612 which is indicated by three dots ('<code>...</code>')
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1613 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	1614 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	1615 instead, it collects all extra arguments and supplies them
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1616 to the function through a <em>vararg expression</em>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1617 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	1618 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	1619 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	1620 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	1621 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	1622 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	1623 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	1624 then no adjustment is made
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1625 (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	1626
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1627
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1628 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1629 As an example, consider the following definitions:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1630
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1631 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1632 function f(a, b) end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1633 function g(a, b, ...) end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1634 function r() return 1,2,3 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1635 </pre>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1636
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1637 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1638 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	1639 to the vararg expression:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1640
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1641 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1642 CALL PARAMETERS
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1643
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1644 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	1645 f(3, 4) a=3, b=4
1090 616761e0b9f6 update documentation for last change Franklin Schmidt <fschmidt@gmail.com> parents: 799 diff changeset	1646 f(3, 4, 5) runtime error
616761e0b9f6 update documentation for last change Franklin Schmidt <fschmidt@gmail.com> parents: 799 diff changeset	1647 f(r(), 10) runtime error
616761e0b9f6 update documentation for last change Franklin Schmidt <fschmidt@gmail.com> parents: 799 diff changeset	1648 f(r()) runtime error
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1649
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1650 g(3) a=3, b=nil, ... --> (nothing)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1651 g(3, 4) a=3, b=4, ... --> (nothing)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1652 g(3, 4, 5, 8) a=3, b=4, ... --> 5 8
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1653 g(5, r()) a=5, b=1, ... --> 2 3
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1654 </pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1655
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1656 <p>
464 eddf7c73373b fix references in the manual Franklin Schmidt <fschmidt@gmail.com> parents: 429 diff changeset	1657 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 Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1658 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	1659 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	1660 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	1661
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1662
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1663 <h3 heading><a name="visibility" href="#visibility">Visibility Rules</a></h3>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1664
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1665 <p>
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1666 Luan is a lexically scoped language.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1667 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	1668 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	1669 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	1670 Consider the following example:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1671
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1672 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1673 x = 10 -- global variable
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1674 do -- new block
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1675 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	1676 print(x) --> 10
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1677 x = x+1
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1678 do -- another block
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1679 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	1680 print(x) --> 12
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1681 end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1682 print(x) --> 11
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1683 end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1684 print(x) --> 10 (the global one)
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1685 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1686
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1687 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1688 Notice that, in a declaration like <code>local x = x</code>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1689 the new <code>x</code> being declared is not in scope yet,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1690 and so the second <code>x</code> refers to the outside variable.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1691
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1694 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	1695 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	1696 defined inside their scope.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1697 A local variable used by an inner function is called
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1698 an <em>upvalue</em>, or <em>external local variable</em>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1699 inside the inner function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1700
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1701
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1702 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1703 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	1704 defines new local variables.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1705 Consider the following example:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1706
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1707 <pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1708 a = {}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1709 local x = 20
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1710 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	1711 local y = 0
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1712 a[i] = function () y=y+1; return x+y end
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1713 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1714 </pre>
417 a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1715
a40e99cf0b0b work on manual Franklin Schmidt <fschmidt@gmail.com> parents: 396 diff changeset	1716 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1717 The loop creates ten closures
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1718 (that is, ten instances of the anonymous function).
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1719 Each of these closures uses a different <code>y</code> variable,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1720 while all of them share the same <code>x</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1721
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1722
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1723
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1724
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1725
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1726 <h2 heading><a name="libs" href="#libs">Standard Libraries</a></h2>
468 9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	1727
9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	1728 <p>
9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	1729 The standard Luan libraries provide useful functions
9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	1730 that are implemented both in Java and in Luan itself.
9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	1731 How each function is implemented shouldn't matter to the user.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1732 Some of these functions provide essential services to the language
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1733 (e.g., <a href="#Luan.type"><code>type</code></a> and <a href="#Luan.get_metatable"><code>get_metatable</code></a>);
468 9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	1734 others provide access to "outside" services (e.g., I/O).
9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	1735
9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	1736
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1737 <h3 heading><a name="default_lib" href="#default_lib">Default Environment</a></h3>
468 9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	1738
9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	1739 <p>
1353 8d95711f6615 replace java() with require "java" Franklin Schmidt <fschmidt@gmail.com> parents: 1342 diff changeset	1740 This is provided by default as a local variable for any Luan code as described in <a href="#env">Environments</a>.
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1741
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1742
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1743 <h4 heading><a name="require" href="#require"><code>require (mod_uri)</code></a></h4>
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1744
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1745 <p>
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1746 Example use:
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1747
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1748 <pre>
693 ca169567ce07 module URIs must now include ".luan" Franklin Schmidt <fschmidt@gmail.com> parents: 685 diff changeset	1749 local Table = require "luan:Table.luan"
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1750 </pre>
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1751
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1752 <p>
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1753 Could be defined as:
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1754
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1755 <pre>
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1756 local function require(mod_name)
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1757 return <a href="#Package.load">Package.load</a>(mod_name) or <a href="#Luan.error">Luan.error</a>("module '"..mod_name.."' not found")
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1758 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1759 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1760
1353 8d95711f6615 replace java() with require "java" Franklin Schmidt <fschmidt@gmail.com> parents: 1342 diff changeset	1761 <p>
8d95711f6615 replace java() with require "java" Franklin Schmidt <fschmidt@gmail.com> parents: 1342 diff changeset	1762 A special case is:
8d95711f6615 replace java() with require "java" Franklin Schmidt <fschmidt@gmail.com> parents: 1342 diff changeset	1763
8d95711f6615 replace java() with require "java" Franklin Schmidt <fschmidt@gmail.com> parents: 1342 diff changeset	1764 <pre>
8d95711f6615 replace java() with require "java" Franklin Schmidt <fschmidt@gmail.com> parents: 1342 diff changeset	1765 require "java"
8d95711f6615 replace java() with require "java" Franklin Schmidt <fschmidt@gmail.com> parents: 1342 diff changeset	1766 </pre>
8d95711f6615 replace java() with require "java" Franklin Schmidt <fschmidt@gmail.com> parents: 1342 diff changeset	1767
8d95711f6615 replace java() with require "java" Franklin Schmidt <fschmidt@gmail.com> parents: 1342 diff changeset	1768 <p>
8d95711f6615 replace java() with require "java" Franklin Schmidt <fschmidt@gmail.com> parents: 1342 diff changeset	1769 This 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.
8d95711f6615 replace java() with require "java" Franklin Schmidt <fschmidt@gmail.com> parents: 1342 diff changeset	1770
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1771
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	1772 <h3 heading><a name="luan_lib" href="#luan_lib">Basic Functions</a></h3>
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1773
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1774 <p>
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1775 Include this library by:
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1776
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1777 <pre>
693 ca169567ce07 module URIs must now include ".luan" Franklin Schmidt <fschmidt@gmail.com> parents: 685 diff changeset	1778 local Luan = require "luan:Luan.luan"
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1779 </pre>
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1780
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1781 <p>
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1782 The basic library provides basic functions to Luan that don't depend on other libaries.
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1783
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1784
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	1785 <h4 heading><a name="Luan.do_file" href="#Luan.do_file"><code>Luan.do_file ([uri])</code></a></h4>
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1786
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1787 <p>
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1788 Could be defined as:
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1789
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1790 <pre>
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1791 function Luan.do_file(uri)
1316 11d3640e739d load_file returns nil for missing file Franklin Schmidt <fschmidt@gmail.com> parents: 1303 diff changeset	1792 local fn = <a href="#Luan.load_file">Luan.load_file</a>(uri) or <a href="#Luan.error">Luan.error</a>("file '"..uri.."' not found")
11d3640e739d load_file returns nil for missing file Franklin Schmidt <fschmidt@gmail.com> parents: 1303 diff changeset	1793 return fn()
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1794 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1795 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1796
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1797
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1798
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	1799 <h4 heading><a name="Luan.error" href="#Luan.error"><code>Luan.error (message)</code></a></h4>
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1800
5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1801 <p>
482 7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	1802 Throws an error containing the message.
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	1803
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	1804 <p>
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	1805 Could be defined as:
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	1806
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1807 <pre>
482 7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	1808 function Luan.error(message)
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	1809 <a href="#Luan.new_error">Luan.new_error</a>(message).throw()
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	1810 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1811 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1812
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1813
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1814
1434 56fb5cd8228d cache compiled code in temp files Franklin Schmidt <fschmidt@gmail.com> parents: 1422 diff changeset	1815 <h4 heading><a name="Luan.eval" href="#Luan.eval"><code>Luan.eval (text [, source_name [, env]])</code></a></h4>
695 5042e487d717 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 693 diff changeset	1816
5042e487d717 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 693 diff changeset	1817 <p>
5042e487d717 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 693 diff changeset	1818 Evaluates <code>text</code> as a Luan expression.
5042e487d717 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 693 diff changeset	1819
5042e487d717 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 693 diff changeset	1820 <p>
5042e487d717 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 693 diff changeset	1821 Could be defined as:
5042e487d717 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 693 diff changeset	1822
5042e487d717 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 693 diff changeset	1823 <pre>
1395 9dfff82dfc59 finish postgres work Franklin Schmidt <fschmidt@gmail.com> parents: 1389 diff changeset	1824 function Luan.eval(text,source_name, env)
9dfff82dfc59 finish postgres work Franklin Schmidt <fschmidt@gmail.com> parents: 1389 diff changeset	1825 return <a href="#Luan.load">Luan.load</a>( "return "..text, source_name or "eval", env )()
695 5042e487d717 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 693 diff changeset	1826 end
5042e487d717 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 693 diff changeset	1827 </pre>
5042e487d717 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 693 diff changeset	1828
5042e487d717 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 693 diff changeset	1829
5042e487d717 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 693 diff changeset	1830
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	1831 <h4 heading><a name="Luan.get_metatable" href="#Luan.get_metatable"><code>Luan.get_metatable (table)</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1832
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1833 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1834 If <code>table</code> does not have a metatable, returns <b>nil</b>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1835 Otherwise,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1836 if the table's metatable has a <code>"__metatable"</code> field,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1837 returns the associated value.
470 5627eb637eb4 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 469 diff changeset	1838 Otherwise, returns the metatable of the given table.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1839
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1840
1373 372906d1d08b minor Franklin Schmidt <fschmidt@gmail.com> parents: 1353 diff changeset	1841 <h4 heading><a name="Luan.hash_code" href="#Luan.ipairs"><code>Luan.hash_code (v)</code></a></h4>
372906d1d08b minor Franklin Schmidt <fschmidt@gmail.com> parents: 1353 diff changeset	1842
372906d1d08b minor Franklin Schmidt <fschmidt@gmail.com> parents: 1353 diff changeset	1843 <p>
372906d1d08b minor Franklin Schmidt <fschmidt@gmail.com> parents: 1353 diff changeset	1844 Returns the hash code of <code>v</code>.
372906d1d08b minor Franklin Schmidt <fschmidt@gmail.com> parents: 1353 diff changeset	1845
372906d1d08b minor Franklin Schmidt <fschmidt@gmail.com> parents: 1353 diff changeset	1846
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	1847 <h4 heading><a name="Luan.ipairs" href="#Luan.ipairs"><code>Luan.ipairs (t)</code></a></h4>
474 00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1848
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1849 <p>
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1850 Returns an iterator function
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1851 so that the construction
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1852
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1853 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1854 for i,v in ipairs(t) do <em>body</em> end
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1855 </pre>
474 00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1856
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1857 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1858 will iterate over the key–value pairs
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1859 (<code>1,t[1]</code>), (<code>2,t[2]</code>), ...,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1860 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	1861
474 00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1862 <p>
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1863 Could be defined as:
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1864
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1865 <pre>
474 00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1866 function Luan.ipairs(t)
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1867 local i = 0
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1868 return function()
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1869 if i < #t then
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1870 i = i + 1
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1871 return i, t[i]
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1872 end
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1873 end
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1874 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1875 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1876
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1877
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1878
1434 56fb5cd8228d cache compiled code in temp files Franklin Schmidt <fschmidt@gmail.com> parents: 1422 diff changeset	1879 <h4 heading><a name="Luan.load" href="#Luan.load"><code>Luan.load (text, [source_name [, env [, persist]]])</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1880
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1881 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1882 Loads a chunk.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1883
474 00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1884 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1885 The <code>text</code> is compiled.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1886 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	1887 returns the compiled chunk as a function;
474 00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1888 otherwise, throws an error.
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1889
00646edc9d92 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 472 diff changeset	1890 <p>
1434 56fb5cd8228d cache compiled code in temp files Franklin Schmidt <fschmidt@gmail.com> parents: 1422 diff changeset	1891 The <code>source_name</code> parameter is a string saying where the text came from. It is used to produce error messages. Defaults to "load".
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1892
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1893 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1894 If the <code>env</code> parameter is supplied, it becomes the <code>_ENV</code> of the chunk.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1895
1434 56fb5cd8228d cache compiled code in temp files Franklin Schmidt <fschmidt@gmail.com> parents: 1422 diff changeset	1896 <p>
56fb5cd8228d cache compiled code in temp files Franklin Schmidt <fschmidt@gmail.com> parents: 1422 diff changeset	1897 The <code>persist</code> parameter is a boolean which determines if the compiled code is persistently cached to a temporary file. Defaults to <code>false</code>.
56fb5cd8228d cache compiled code in temp files Franklin Schmidt <fschmidt@gmail.com> parents: 1422 diff changeset	1898
56fb5cd8228d cache compiled code in temp files Franklin Schmidt <fschmidt@gmail.com> parents: 1422 diff changeset	1899
56fb5cd8228d cache compiled code in temp files Franklin Schmidt <fschmidt@gmail.com> parents: 1422 diff changeset	1900 <h4 heading><a name="Luan.load_file" href="#Luan.load_file"><code>Luan.load_file (file_uri)</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1901
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1902 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1903 Similar to <a href="#Luan.load"><code>load</code></a>,
1434 56fb5cd8228d cache compiled code in temp files Franklin Schmidt <fschmidt@gmail.com> parents: 1422 diff changeset	1904 but gets the chunk from file <code>file_uri</code>.
56fb5cd8228d cache compiled code in temp files Franklin Schmidt <fschmidt@gmail.com> parents: 1422 diff changeset	1905 <code>file_uri</code> can be a string or a uri table.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1906
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1907
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	1908 <h4 heading><a name="Luan.new_error" href="#Luan.new_error"><code>Luan.new_error (message)</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1909
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1910 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1911 Creates a new error table containing the message assigned to "<code>message</code>". The error table also contains a <code>throw</code> function which throws the error. The table also contains a list of stack trace elements where each stack trace element is a table containing "<code>source</code>", "<code>line</code>", and possible "<code>call_to</code>". The table also has a metatable containing "<code>__to_string</code>" to render the error.
482 7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	1912
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	1913 <p>
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	1914 To print the current stack trace, you could do:
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	1915
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1916 <pre>
482 7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	1917 Io.print( Luan.new_error "stack" )
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1918 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1919
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1920
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	1921 <h4 heading><a name="Luan.pairs" href="#Luan.pairs"><code>Luan.pairs (t)</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1922
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1923 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1924 If <code>t</code> has a metamethod <code>__pairs</code>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1925 calls it with <code>t</code> as argument and returns the
475 7ac0891718eb documentation Franklin Schmidt <fschmidt@gmail.com> parents: 474 diff changeset	1926 result from the call.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1927
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1928
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1929 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1930 Otherwise,
475 7ac0891718eb documentation Franklin Schmidt <fschmidt@gmail.com> parents: 474 diff changeset	1931 returns a function
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1932 so that the construction
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1933
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1934 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1935 for k,v in pairs(t) do <em>body</em> end
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1936 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1937
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1938 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1939 will iterate over all key–value pairs of table <code>t</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1940
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1941
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1942
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	1943 <h4 heading><a name="Luan.pcall" href="#Luan.pcall"><code>Luan.pcall (f [, arg1, ···])</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1944
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1945 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1946 Calls function <code>f</code> with
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1947 the given arguments in <em>protected mode</em>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1948 This means that any error inside <code>f</code> is not propagated;
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1949 instead, <code>pcall</code> catches the error
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1950 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	1951 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	1952 which is true if the call succeeds without errors.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1953 In such case, <code>pcall</code> also returns all results from the call,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1954 after this first result.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1955 In case of any error, <code>pcall</code> returns <b>false</b> plus the error.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1956
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1957
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1958
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1959
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1960 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1961 <hr><h3><a name="pdf-print"><code>print (···)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1962 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	1963 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	1964 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	1965 <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	1966 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	1967 for instance for debugging.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	1968 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	1969 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	1970
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual 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
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	1973 <h4 heading><a name="Luan.range" href="#Luan.range"><code>Luan.range (start, stop [, step])</code></a></h4>
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1974
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1975 <p>
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1976 Based on <a href="https://docs.python.org/2/library/functions.html#range">the Python range() function</a>, this lets one iterate through a sequence of numbers.
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1977
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1978 <p>
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1979 Example use:
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1980
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1981 <pre>
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1982 for i in range(1,10) do
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1983 Io.print("count up:",i)
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1984 end
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1985 for i in range(10,0,-1) do
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1986 Io.print("count down:",i)
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1987 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1988 </pre>
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1989
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1990 <p>
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1991 Could be defined as:
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1992
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	1993 <pre>
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1994 function Luan.range(start, stop, step)
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1995 step = step or 1
478 eb6d90fb0b5c documentation Franklin Schmidt <fschmidt@gmail.com> parents: 476 diff changeset	1996 step == 0 and <a href="#Luan.error">Luan.error</a> "bad argument #3 (step may not be zero)"
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1997 local i = start
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1998 return function()
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	1999 if step > 0 and i <= stop or step < 0 and i >= stop then
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2000 local rtn = i
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2001 i = i + step
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2002 return rtn
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2003 end
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2004 end
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2005 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2006 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2007
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2008
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2009
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2010 <h4 heading><a name="Luan.raw_equal" href="#Luan.raw_equal"><code>Luan.raw_equal (v1, v2)</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2011
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2012 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2013 Checks whether <code>v1</code> is equal to <code>v2</code>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2014 without invoking any metamethod.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2015 Returns a boolean.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2016
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2017
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2018
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2019 <h4 heading><a name="Luan.raw_get" href="#Luan.raw_get"><code>Luan.raw_get (table, index)</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2020
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2021 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2022 Gets the real value of <code>table[index]</code>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2023 without invoking any metamethod.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2024 <code>table</code> must be a table;
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2025 <code>index</code> may be any value.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2026
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2027
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2028
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2029 <h4 heading><a name="Luan.raw_len" href="#Luan.raw_len"><code>Luan.raw_len (v)</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2030
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2031 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2032 Returns the length of the object <code>v</code>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2033 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	2034 without invoking any metamethod.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2035 Returns an integer.
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
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2039 <h4 heading><a name="Luan.raw_set" href="#Luan.raw_set"><code>Luan.raw_set (table, index, value)</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2040
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2041 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2042 Sets the real value of <code>table[index]</code> to <code>value</code>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2043 without invoking any metamethod.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2044 <code>table</code> must be a table,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2045 <code>index</code> any value different from <b>nil</b>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2046 and <code>value</code> any Lua value.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2047
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2048
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2049 <h4 heading><a name="Luan.set_metatable" href="#Luan.set_metatable"><code>Luan.set_metatable (table, metatable)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2050
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2051 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2052 Sets the metatable for the given table.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2053 If <code>metatable</code> is <b>nil</b>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2054 removes the metatable of the given table.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2055 If the original metatable has a <code>"__metatable"</code> field,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2056 raises an error.
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
1389 eb8b35dccd99 cleanup and stringify change Franklin Schmidt <fschmidt@gmail.com> parents: 1384 diff changeset	2059 <h4 heading><a name="Luan.stringify" href="#Luan.stringify"><code>Luan.stringify (v [,options])</code></a></h4>
eb8b35dccd99 cleanup and stringify change Franklin Schmidt <fschmidt@gmail.com> parents: 1384 diff changeset	2060
eb8b35dccd99 cleanup and stringify change Franklin Schmidt <fschmidt@gmail.com> parents: 1384 diff changeset	2061 <p>
eb8b35dccd99 cleanup and stringify change Franklin Schmidt <fschmidt@gmail.com> parents: 1384 diff changeset	2062 Receives a value of any type and converts it to a string that is a Luan expression. <code>options</code> is a table. If <code>options.strict==true</code> then invalid types throw an error. Otherwise invalid types are represented but the resulting expression is invalid. If <code>options.number_types==true</code> then numbers will be wrapped in functions for their type.
1189 73d754b1889f add stringify Franklin Schmidt <fschmidt@gmail.com> parents: 1164 diff changeset	2063
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2064
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2065 <h4 heading><a name="Luan.to_string" href="#Luan.to_string"><code>Luan.to_string (v)</code></a></h4>
475 7ac0891718eb documentation Franklin Schmidt <fschmidt@gmail.com> parents: 474 diff changeset	2066
7ac0891718eb documentation Franklin Schmidt <fschmidt@gmail.com> parents: 474 diff changeset	2067 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2068 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	2069 converts it to a string in a human-readable format.
475 7ac0891718eb documentation Franklin Schmidt <fschmidt@gmail.com> parents: 474 diff changeset	2070
7ac0891718eb documentation Franklin Schmidt <fschmidt@gmail.com> parents: 474 diff changeset	2071 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2072 If the metatable of <code>v</code> has a <code>"__to_string"</code> field,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2073 then <code>to_string</code> calls the corresponding value
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2074 with <code>v</code> as argument,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2075 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	2076
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2077
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2078
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2079 <h4 heading><a name="Luan.try" href="#Luan.try"><code>Luan.try (t, ···)</code></a></h4>
589 97c8ae330efe add varargs to Luan.try; Franklin Schmidt <fschmidt@gmail.com> parents: 581 diff changeset	2080
97c8ae330efe add varargs to Luan.try; Franklin Schmidt <fschmidt@gmail.com> parents: 581 diff changeset	2081 <p>
97c8ae330efe add varargs to Luan.try; Franklin Schmidt <fschmidt@gmail.com> parents: 581 diff changeset	2082 Implements try-catch as found in other languages where each block is in table <code>t</code>. <code>t[1]</code> is the "try" block. The <code>t.catch</code> and <code>t.finally</code> blocks are optional. Any extra arguments are passed to the "try" function. Returns the result of the "try" block or the "catch" block.
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2083
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2084 <p>
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2085 Example use:
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2086
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2087 <pre>
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2088 try {
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2089 function()
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2090 a_dangerous_fn()
702 87970832a3c3 improve Http_test Franklin Schmidt <fschmidt@gmail.com> parents: 695 diff changeset	2091 end
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2092 catch = function(e)
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2093 -- handle error
702 87970832a3c3 improve Http_test Franklin Schmidt <fschmidt@gmail.com> parents: 695 diff changeset	2094 end
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2095 finally = function()
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2096 -- clean up
702 87970832a3c3 improve Http_test Franklin Schmidt <fschmidt@gmail.com> parents: 695 diff changeset	2097 end
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2098 }
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2099 </pre>
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2100
482 7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2101 <p>
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2102 Could be defined as:
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2103
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2104 <pre>
482 7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2105 function Luan.try(t)
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2106 local r = { <a href="#Luan.pcall">Luan.pcall</a>(t[1]) }
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2107 if r[1] then
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2108 Table.remove(r,1)
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2109 elseif t.catch ~= nil then
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2110 r = { t.catch(r[2]) }
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2111 else
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2112 t.finally and t.finally()
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2113 r[2].throw()
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2114 end
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2115 t.finally and t.finally()
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2116 return Table.unpack(r)
7e9fcfbf22ec documentation Franklin Schmidt <fschmidt@gmail.com> parents: 479 diff changeset	2117 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2118 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2119
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2120
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2121 <h4 heading><a name="Luan.type" href="#Luan.type"><code>Luan.type (v)</code></a></h4>
475 7ac0891718eb documentation Franklin Schmidt <fschmidt@gmail.com> parents: 474 diff changeset	2122
7ac0891718eb documentation Franklin Schmidt <fschmidt@gmail.com> parents: 474 diff changeset	2123 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2124 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	2125 The possible results of this function are
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2126 "<code>nil</code>" (a string, not the value <b>nil</b>),
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2127 "<code>number</code>",
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2128 "<code>string</code>",
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2129 "<code>binary</code>",
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2130 "<code>boolean</code>",
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2131 "<code>table</code>",
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2132 "<code>function</code>",
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2133 and "<code>java</code>".
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2134
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2135
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2136 <h4 heading><a name="Luan.values" href="#Luan.values"><code>Luan.values (···)</code></a></h4>
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2137
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2138 <p>
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2139 Returns a function so that the construction
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2140
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2141 <pre>
1276 623dfe0e2e73 change Luan.values Franklin Schmidt <fschmidt@gmail.com> parents: 1272 diff changeset	2142 for i, v in Luan.values(···) do <em>body</em> end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2143 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2144
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2145 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2146 will iterate over all values of <code>···</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2147
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2148
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2149
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2150 <h4 heading><a name="Luan.VERSION" href="#Luan.VERSION"><code>Luan.VERSION</code></a></h4>
475 7ac0891718eb documentation Franklin Schmidt <fschmidt@gmail.com> parents: 474 diff changeset	2151
7ac0891718eb documentation Franklin Schmidt <fschmidt@gmail.com> parents: 474 diff changeset	2152 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2153 A global variable (not a function) that
1325 28c1fc6d9d29 website - make docs html Franklin Schmidt <fschmidt@gmail.com> parents: 1324 diff changeset	2154 holds a string containing the current Luan version.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2155
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2156
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2157
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2158
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2159
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2160
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	2161 <h3 heading><a name="package_lib" href="#package_lib">Modules</a></h3>
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2162
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2163 <p>
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2164 Include this library by:
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2165
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2166 <pre>
693 ca169567ce07 module URIs must now include ".luan" Franklin Schmidt <fschmidt@gmail.com> parents: 685 diff changeset	2167 local Package = require "luan:Package.luan"
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2168 </pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2169
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2170 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2171 The package library provides basic
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2172 facilities for loading modules in Luan.
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2173
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2174
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2175 <h4 heading><a name="Package.load" href="#Package.load"><code>Package.load (mod_uri)</code></a></h4>
371 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 Loads the given module.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2179 The function starts by looking into the <a href="#Package.loaded"><code>Package.loaded</code></a> table
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2180 to determine whether <code>mod_uri</code> is already loaded.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2181 If it is, then <code>Package.load</code> returns the value stored
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2182 at <code>Package.loaded[mod_uri]</code>.
476 cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2183 Otherwise, it tries to load a new value for the module.
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2184
cd22e4694ea3 documentation Franklin Schmidt <fschmidt@gmail.com> parents: 475 diff changeset	2185 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2186 To load a new value, <code>Package.load</code> first checks if <code>mod_uri</code> starts with "<b>java:</b>". If yes, then this is a Java class which is loaded by special Java code.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2187
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2188 <p>
799 9c13a15a4002 Package.load() now returns false instead of null, and caches the result. This cleans up the luan.isLocked issues. Franklin Schmidt <fschmidt@gmail.com> parents: 793 diff changeset	2189 Otherwise <code>Package.load</code> tries to read the text of the file referred to by <code>mod_uri</code>. If the file doesn't exist, then <code>Package.load</code> returns <b>false</b>. If the file exists, then its content is compiled into a chunk by calling <a href="#Luan.load"><code>Luan.load</code></a>. This chunk is run passing in <code>mod_uri</code> as an argument. The value returned by the chunk must not be <b>nil</b> and is loaded.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2190
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2191 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2192 If a new value for the module successful loaded, then it is stored in <code>Package.loaded[mod_uri]</code>. The value is returned.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2193
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2194
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2195
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2196
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2197 <h4 heading><a name="Package.loaded" href="#Package.loaded"><code>Package.loaded</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2198
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2199
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2200 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2201 A table used by <a href="#Package.load"><code>Package.load</code></a> to control which
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2202 modules are already loaded.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2203 When you load a module <code>mod_uri</code> and
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2204 <code>Package.loaded[mod_uri]</code> is not <b>nil</b>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2205 <a href="#Package.load"><code>Package.load</code></a> simply returns the value stored there.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2206
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2207
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2208 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2209 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	2210 assignments to this variable do not change the
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2211 table used by <a href="#Package.load"><code>Package.load</code></a>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2212
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2213
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2214
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2215
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2216
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2217
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	2218 <h3 heading><a name="string_lib" href="#string_lib">String Manipulation</a></h3>
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2219
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2220 <p>
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2221 Include this library by:
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2222
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2223 <pre>
693 ca169567ce07 module URIs must now include ".luan" Franklin Schmidt <fschmidt@gmail.com> parents: 685 diff changeset	2224 local String = require "luan:String.luan"
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2225 </pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2226
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2227 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2228 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	2229 such as finding and extracting substrings, and pattern matching.
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2230 When indexing a string in Luan, the first character is at position 1
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2231 (not at 0, as in Java).
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2232 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	2233 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	2234 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	2235
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2236
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2237
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2238 <h4 heading><a name="String.char" href="#String.char"><code>String.char (···)</code></a></h4>
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2239
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2240 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2241 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	2242 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	2243 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	2244 to its corresponding argument.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2245
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2246
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2247 <h4 heading><a name="String.encode" href="#String.encode"><code>String.encode (s)</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2248
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2249 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2250 Encodes argument <code>s</code> into a string that can be placed in quotes so as to return the original value of the string.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2251
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2252
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2253
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2254
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2255 <h4 heading><a name="String.find" href="#String.find"><code>String.find (s, pattern [, init [, plain]])</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2256
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2257 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2258 Looks for the first match of
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2259 <code>pattern</code> (see <a href="http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html">Pattern</a>) in the string <code>s</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2260 If it finds a match, then <code>find</code> returns the indices of <code>s</code>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2261 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	2262 otherwise, it returns <b>nil</b>.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2263 A third, optional numerical argument <code>init</code> specifies
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2264 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	2265 its default value is 1 and can be negative.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2266 A value of <b>true</b> as a fourth, optional argument <code>plain</code>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2267 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	2268 so the function does a plain "find substring" operation,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2269 with no characters in <code>pattern</code> being considered magic.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2270 Note that if <code>plain</code> is given, then <code>init</code> must be given as well.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2271
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2272 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2273 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	2274 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	2275 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	2276 after the two indices.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2279
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2280
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2281 <h4 heading><a name="String.format" href="#String.format"><code>String.format (formatstring, ···)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2282
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2285 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	2286 following the description given in its first argument (which must be a string).
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2287 The format string follows the same rules as the Java function <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#format(java.lang.String,%20java.lang.Object...)"><code>String.format</code></a> because Luan calls this internally.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2288
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2289 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2290 Note that Java's <code>String.format</code> is too stupid to convert between ints and floats, so you must provide the right kind of number.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2291
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2292
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2293
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2294 <h4 heading><a name="String.gmatch" href="#String.gmatch"><code>String.gmatch (s, pattern)</code></a></h4>
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2295
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2296 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2297 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	2298 each time it is called,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2299 returns the next captures from <code>pattern</code> (see <a href="http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html">Pattern</a>)
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2300 over the string <code>s</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2301 If <code>pattern</code> specifies no captures,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2302 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	2303
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2304
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2305 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2306 As an example, the following loop
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2307 will iterate over all the words from string <code>s</code>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2308 printing one per line:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2309
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2310 <pre>
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2311 local s = "hello world from Lua"
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2312 for w in String.gmatch(s, [[\w+]]) do
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2313 print(w)
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2314 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2315 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2316
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2317 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2318 The next example collects all pairs <code>key=value</code> from the
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2319 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	2320
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2321 <pre>
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2322 local t = {}
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2323 local s = "from=world, to=Lua"
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2324 for k, v in String.gmatch(s, [[(\w+)=(\w+)]]) do
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2325 t[k] = v
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2326 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2327 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2328
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2329 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2330 For this function, a caret '<code>^</code>' at the start of a pattern does not
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2331 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	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
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2335 <h4 heading><a name="String.gsub" href="#String.gsub"><code>String.gsub (s, pattern, repl [, n])</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2336
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2337 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2338 Returns a copy of <code>s</code>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2339 in which all (or the first <code>n</code>, if given)
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2340 occurrences of the <code>pattern</code> (see <a href="http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html">Pattern</a>) have been
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2341 replaced by a replacement string specified by <code>repl</code>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2342 which can be a string, a table, or a function.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2343 <code>gsub</code> also returns, as its second value,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2344 the total number of matches that occurred.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2345 The name <code>gsub</code> comes from <em>Global SUBstitution</em>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2346
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2347
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2348 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2349 If <code>repl</code> is a string, then its value is used for replacement.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2350 The character <code>\</code> works as an escape character.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2351 Any sequence in <code>repl</code> of the form <code>$<em>d</em></code>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2352 with <em>d</em> between 1 and 9,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2353 stands for the value of the <em>d</em>-th captured substring.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2354 The sequence <code>$0</code> stands for the whole match.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2355
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2356
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2357 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2358 If <code>repl</code> is a table, then the table is queried for every match,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2359 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	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>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2363 If <code>repl</code> is a function, then this function is called every time a
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2364 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	2365 in order.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2366
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2367
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2368 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2369 In any case,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2370 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	2371 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	2372
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2373
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2374 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2375 If the value returned by the table query or by the function call
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2376 is not <b>nil</b>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2377 then it is used as the replacement string;
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2378 otherwise, if it is <b>nil</b>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2379 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	2380 (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	2381
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2382
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2383 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2384 Here are some examples:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2385
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2386 <pre>
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2387 x = String.gsub("hello world", [[(\w+)]], "$1 $1")
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2388 --> 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	2389
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2390 x = String.gsub("hello world", [[\w+]], "$0 $0", 1)
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2391 --> x="hello hello world"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2392
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2393 x = String.gsub("hello world from Luan", [[(\w+)\s*(\w+)]], "$2 $1")
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2394 --> x="world hello Luan from"
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2395
e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2396 x = String.gsub("4+5 = $return 4+5$", [[\$(.*?)\$]], function (s)
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2397 return load(s)()
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2398 end)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2399 --> x="4+5 = 9"
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2400
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2401 local t = {name="lua", version="5.3"}
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2402 x = String.gsub("$name-$version.tar.gz", [[\$(\w+)]], t)
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2403 --> x="lua-5.3.tar.gz"
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2404 </pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2405
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2406
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2407 <h4 heading><a name="String.lower" href="#String.lower"><code>String.lower (s)</code></a></h4>
555 e25ba7a2e816 some String documentation and fixes Franklin Schmidt <fschmidt@gmail.com> parents: 553 diff changeset	2408 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2409 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	2410 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	2411 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	2412
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2413
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2414
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2415 <h4 heading><a name="String.match" href="#String.match"><code>String.match (s, pattern [, init])</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2416
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2417 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2418 Looks for the first <em>match</em> of
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2419 <code>pattern</code> (see <a href="http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html">Pattern</a>) in the string <code>s</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2420 If it finds one, then <code>match</code> returns
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2421 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	2422 otherwise it returns <b>nil</b>.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2423 If <code>pattern</code> specifies no captures,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2424 then the whole match is returned.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2425 A third, optional numerical argument <code>init</code> specifies
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2426 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	2427 its default value is 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	2428
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2429
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2430 <h4 heading><a name="String.matches" href="#String.matches"><code>String.matches (s, pattern)</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2431 <p>
629 35dde32c02ab change String.matches() Franklin Schmidt <fschmidt@gmail.com> parents: 626 diff changeset	2432 Returns a boolean indicating whether the <code>pattern</code> can be found in string <code>s</code>.
35dde32c02ab change String.matches() Franklin Schmidt <fschmidt@gmail.com> parents: 626 diff changeset	2433 This function is equivalent to
35dde32c02ab change String.matches() Franklin Schmidt <fschmidt@gmail.com> parents: 626 diff changeset	2434
35dde32c02ab change String.matches() Franklin Schmidt <fschmidt@gmail.com> parents: 626 diff changeset	2435 <pre>
35dde32c02ab change String.matches() Franklin Schmidt <fschmidt@gmail.com> parents: 626 diff changeset	2436 return String.match(s,pattern) ~= nil
35dde32c02ab change String.matches() Franklin Schmidt <fschmidt@gmail.com> parents: 626 diff changeset	2437 </pre>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2438
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2439
1422 e48290f3d9fb better quoting Franklin Schmidt <fschmidt@gmail.com> parents: 1395 diff changeset	2440 <h4 heading><a name="String.regex_quote" href="#String.regex_quote"><code>String.regex_quote (s)</code></a></h4>
e48290f3d9fb better quoting Franklin Schmidt <fschmidt@gmail.com> parents: 1395 diff changeset	2441 <p>
e48290f3d9fb better quoting Franklin Schmidt <fschmidt@gmail.com> parents: 1395 diff changeset	2442 Returns a string which matches the literal string <code>s</code> in a regular expression. This function is simply the Java method <a href="http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html#quote(java.lang.String)"><code>Pattern.quote</code></a>.
e48290f3d9fb better quoting Franklin Schmidt <fschmidt@gmail.com> parents: 1395 diff changeset	2443
e48290f3d9fb better quoting Franklin Schmidt <fschmidt@gmail.com> parents: 1395 diff changeset	2444
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2445 <h4 heading><a name="String.rep" href="#String.rep"><code>String.rep (s, n [, sep])</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2446 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2447 Returns a string that is the concatenation of <code>n</code> copies of
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2448 the string <code>s</code> separated by the string <code>sep</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2449 The default value for <code>sep</code> is the empty string
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2450 (that is, no separator).
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2451 Returns the empty string if <code>n</code> is not positive.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2452
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2453
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2454
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2455
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2456 <h4 heading><a name="String.reverse" href="#String.reverse"><code>String.reverse (s)</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2457 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2458 Returns a string that is the string <code>s</code> reversed.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2459
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2460
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2461
1195 9a57f0b16c2b better String.split Franklin Schmidt <fschmidt@gmail.com> parents: 1189 diff changeset	2462 <h4 heading><a name="String.split" href="#String.match"><code>String.split (s, pattern [, limit])</code></a></h4>
9a57f0b16c2b better String.split Franklin Schmidt <fschmidt@gmail.com> parents: 1189 diff changeset	2463
9a57f0b16c2b better String.split Franklin Schmidt <fschmidt@gmail.com> parents: 1189 diff changeset	2464 <p>
9a57f0b16c2b better String.split Franklin Schmidt <fschmidt@gmail.com> parents: 1189 diff changeset	2465 Splits <code>s</code> using regex <code>pattern</code> and returns the results. If <code>limit</code> is positive, then only returns at most that many results. If <code>limit</code> is zero, then remove trailing empty results.
9a57f0b16c2b better String.split Franklin Schmidt <fschmidt@gmail.com> parents: 1189 diff changeset	2466
9a57f0b16c2b better String.split Franklin Schmidt <fschmidt@gmail.com> parents: 1189 diff changeset	2467
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2468
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2469 <h4 heading><a name="String.sub" href="#String.sub"><code>String.sub (s, i [, j])</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2470
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2471 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2472 Returns the substring of <code>s</code> that
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2473 starts at <code>i</code> and continues until <code>j</code>;
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2474 <code>i</code> and <code>j</code> can be negative.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2475 If <code>j</code> is absent, then it is assumed to be equal to -1
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2476 (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	2477 In particular,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2478 the call <code>string.sub(s,1,j)</code> returns a prefix of <code>s</code>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2479 with length <code>j</code>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2480 and <code>string.sub(s, -i)</code> returns a suffix of <code>s</code>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2481 with length <code>i</code>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2482
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2483
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2484 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2485 If, after the translation of negative indices,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2486 <code>i</code> is less than 1,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2487 it is corrected to 1.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2488 If <code>j</code> is greater than the string length,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2489 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	2490 If, after these corrections,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2491 <code>i</code> is greater than <code>j</code>,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2492 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	2493
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2494
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2495
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2496 <h4 heading><a name="String.to_binary" href="#String.to_binary"><code>String.to_binary (s)</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2497
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2498 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2499 Converts a string to a binary by calling the Java method <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#getBytes()"><code>String.getBytes</code></a>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2500
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2501
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2502
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2503 <h4 heading><a name="String.to_number" href="#String.to_number"><code>String.to_number (s [, base])</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2504
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2505 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2506 When called with no <code>base</code>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2507 <code>to_number</code> tries to convert its argument to a number.
556 d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2508 If the argument is
d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2509 a string convertible to a number,
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2510 then <code>to_number</code> returns this number;
556 d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2511 otherwise, it returns <b>nil</b>.
d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2512
d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2513 The conversion of strings can result in integers or floats.
d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2514
d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2515
d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2516 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2517 When called with <code>base</code>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2518 then <code>s</code> must be a string to be interpreted as
556 d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2519 an integer numeral in that base.
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2520 In bases above 10, the letter '<code>A</code>' (in either upper or lower case)
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2521 represents 10, '<code>B</code>' represents 11, and so forth,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2522 with '<code>Z</code>' representing 35.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2523 If the string <code>s</code> is not a valid numeral in the given base,
556 d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2524 the function returns <b>nil</b>.
d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2525
d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2526
d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2527
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2528 <h4 heading><a name="String.trim" href="#String.trim"><code>String.trim (s)</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2529
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2530 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2531 Removes the leading and trailing whitespace by calling the Java method <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#trim()"><code>String.trim</code></a>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2532
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2533
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2534
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2535
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2536 <h4 heading><a name="String.unicode" href="#String.unicode"><code>String.unicode (s [, i [, j]])</code></a></h4>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2537
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2538 <p>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2539 Returns the internal numerical codes of the characters <code>s[i]</code>,
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2540 <code>s[i+1]</code>, ..., <code>s[j]</code>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2541 The default value for <code>i</code> is 1;
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2542 the default value for <code>j</code> is <code>i</code>.
556 d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2543 These indices are corrected
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2544 following the same rules of function <a href="#String.sub"><code>String.sub</code></a>.
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2545
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2546
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2547
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2548
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 556 diff changeset	2549
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2550 <h4 heading><a name="String.upper" href="#String.upper"><code>String.upper (s)</code></a></h4>
556 d02f43598ba3 finish String documentation Franklin Schmidt <fschmidt@gmail.com> parents: 555 diff changeset	2551 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2552 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	2553 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	2554 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	2555 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	2556
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2557
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2558
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2559
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2560
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	2561 <h3 heading><a name="binary_lib" href="#binary_lib">Binary Manipulation</a></h3>
567 6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2562
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2563 <p>
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2564 Include this library by:
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2565
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2566 <pre>
693 ca169567ce07 module URIs must now include ".luan" Franklin Schmidt <fschmidt@gmail.com> parents: 685 diff changeset	2567 local Binary = require "luan:Binary.luan"
567 6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2568 </pre>
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2569
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2570
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2571 <h4 heading><a name="Binary.binary" href="#Binary.binary"><code>Binary.binary (···)</code></a></h4>
567 6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2572
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2573 <p>
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2574 Receives zero or more bytes (as integers).
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2575 Returns a binary with length equal to the number of arguments,
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2576 in which each byte has the internal numerical code equal
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2577 to its corresponding argument.
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2578
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2579
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2580 <h4 heading><a name="Binary.byte" href="#Binary.byte"><code>Binary.byte (b [, i [, j]])</code></a></h4>
567 6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2581
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2582 <p>
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2583 Returns the internal numerical codes of the bytes <code>b[i]</code>,
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2584 <code>b[i+1]</code>, ..., <code>b[j]</code>.
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2585 The default value for <code>i</code> is 1;
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2586 the default value for <code>j</code> is <code>i</code>.
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2587 These indices are corrected
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2588 following the same rules of function <a href="#String.sub"><code>String.sub</code></a>.
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2589
6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2590
1257 e38f5869e9df don't reset in send_redirect and other improvements Franklin Schmidt <fschmidt@gmail.com> parents: 1216 diff changeset	2591 <h4 heading><a name="Binary.to_string" href="#Binary.to_string"><code>Binary.to_string (b [,charset])</code></a></h4>
e38f5869e9df don't reset in send_redirect and other improvements Franklin Schmidt <fschmidt@gmail.com> parents: 1216 diff changeset	2592 <p>
e38f5869e9df don't reset in send_redirect and other improvements Franklin Schmidt <fschmidt@gmail.com> parents: 1216 diff changeset	2593 If <code>charset</code> is not nil then converts the binary <code>b</code> to a string using the Java <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#String(byte[],%20java.lang.String)">String constructor</a>, else makes each byte a char.
567 6c00b8a59240 document Binary Franklin Schmidt <fschmidt@gmail.com> parents: 566 diff changeset	2594
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2595
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2596
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2597
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	2598 <h3 heading><a name="table_lib" href="#table_lib">Table Manipulation</a></h3>
565 22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2599
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2600 <p>
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2601 Include this library by:
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2602
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2603 <pre>
693 ca169567ce07 module URIs must now include ".luan" Franklin Schmidt <fschmidt@gmail.com> parents: 685 diff changeset	2604 local Table = require "luan:Table.luan"
565 22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2605 </pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2606
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2607 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2608 This library provides generic functions for table manipulation.
565 22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2609 It provides all its functions inside the table <code>Table</code>.
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2610
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2611
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2612
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2613 <h4 heading><a name="Table.clear" href="#Table.clear"><code>Table.clear (tbl)</code></a></h4>
580 1e69d9c21461 add Table.clear(); Franklin Schmidt <fschmidt@gmail.com> parents: 567 diff changeset	2614
1e69d9c21461 add Table.clear(); Franklin Schmidt <fschmidt@gmail.com> parents: 567 diff changeset	2615 <p>
1e69d9c21461 add Table.clear(); Franklin Schmidt <fschmidt@gmail.com> parents: 567 diff changeset	2616 Clears the table.
1e69d9c21461 add Table.clear(); Franklin Schmidt <fschmidt@gmail.com> parents: 567 diff changeset	2617
1e69d9c21461 add Table.clear(); Franklin Schmidt <fschmidt@gmail.com> parents: 567 diff changeset	2618
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2619 <h4 heading><a name="Table.concat" href="#Table.concat"><code>Table.concat (list [, sep [, i [, j]]])</code></a></h4>
565 22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2620
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2621 <p>
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2622 Given a list,
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2623 returns the string <code>list[i]..sep..list[i+1] ··· sep..list[j]</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2624 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	2625 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	2626 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	2627 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	2628
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2629
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2630 <h4 heading><a name="Table.copy" href="#Table.copy"><code>Table.copy (tbl [, i [, j]])</code></a></h4>
565 22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2631
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2632 <p>
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2633 If <code>i</code> is <code>nil</code>, returns a shallow copy of <code>tbl</code>.
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2634 Otherwise returns a new table which is a list of the elements <code>tbl[i] ··· tbl[j]</code>.
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2635 By default, <code>j</code> is <code>#tbl</code>.
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2636
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2637
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2638
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2639 <h4 heading><a name="Table.insert" href="#Table.insert"><code>Table.insert (list, pos, value)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2640
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2641 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2642 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	2643 shifting up the elements
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2644 <code>list[pos], list[pos+1], ···, list[#list]</code>.
565 22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2645
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2646
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2647
1100 ad6b3b9fef40 add Table.is_empty() and Table.size() Franklin Schmidt <fschmidt@gmail.com> parents: 1092 diff changeset	2648 <h4 heading><a name="Table.is_empty" href="#Table.is_empty"><code>Table.is_empty (tbl)</code></a></h4>
ad6b3b9fef40 add Table.is_empty() and Table.size() Franklin Schmidt <fschmidt@gmail.com> parents: 1092 diff changeset	2649
ad6b3b9fef40 add Table.is_empty() and Table.size() Franklin Schmidt <fschmidt@gmail.com> parents: 1092 diff changeset	2650
ad6b3b9fef40 add Table.is_empty() and Table.size() Franklin Schmidt <fschmidt@gmail.com> parents: 1092 diff changeset	2651
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2652 <h4 heading><a name="Table.pack" href="#Table.pack"><code>Table.pack (···)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2653
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2654 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2655 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	2656 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	2657 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	2658
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2659
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
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2662 <h4 heading><a name="Table.remove" href="#Table.remove"><code>Table.remove (list, pos)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2663
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2664
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2665 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2666 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	2667 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	2668 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	2669 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	2670 <code>list[pos+1], list[pos+2], ···, list[#list]</code>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2671 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	2672 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	2673 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	2674 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	2675
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2676
565 22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2677
1100 ad6b3b9fef40 add Table.is_empty() and Table.size() Franklin Schmidt <fschmidt@gmail.com> parents: 1092 diff changeset	2678 <h4 heading><a name="Table.size" href="#Table.size"><code>Table.size (tbl)</code></a></h4>
ad6b3b9fef40 add Table.is_empty() and Table.size() Franklin Schmidt <fschmidt@gmail.com> parents: 1092 diff changeset	2679
ad6b3b9fef40 add Table.is_empty() and Table.size() Franklin Schmidt <fschmidt@gmail.com> parents: 1092 diff changeset	2680
565 22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2681
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2682 <h4 heading><a name="Table.sort" href="#Table.sort"><code>Table.sort (list [, comp])</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	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 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	2686 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	2687 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	2688 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	2689 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	2690 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	2691 (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	2692 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	2693 then the standard Lua operator <code><</code> is used instead.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2694
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2695 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2696 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	2697 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	2698 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	2699
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2700
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2701
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2702 <h4 heading><a name="Table.unpack" href="#Table.unpack"><code>Table.unpack (list [, i [, j]])</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2703
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2704 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2705 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	2706 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	2707
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2708 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2709 return list[i], list[i+1], ···, list[j]
565 22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2710 </pre>
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2711
22bfd8a2eaee do Table documentation; Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	2712 <p>
1277 5ba660381bd5 fix Io.print() Franklin Schmidt <fschmidt@gmail.com> parents: 1276 diff changeset	2713 By default, <code>i</code> is 1 and <code>j</code> is <code>list.n or #list</code>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2714
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2715
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2716
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2717
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	2718 <h3 heading><a name="number_lib" href="#number_lib">Number Manipulation</a></h3>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2719
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2720 <p>
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2721 Include this library by:
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2722
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2723 <pre>
693 ca169567ce07 module URIs must now include ".luan" Franklin Schmidt <fschmidt@gmail.com> parents: 685 diff changeset	2724 local Number = require "luan:Number.luan"
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2725 </pre>
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2726
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2727
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2728 <h4 heading><a name="Number.double" href="#Number.double"><code>Number.double (x)</code></a></h4>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2729 <p>
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2730 Returns <code>x</code> as a double.
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2731
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2732
1342 60599adc27b8 add lucene search options Franklin Schmidt <fschmidt@gmail.com> parents: 1327 diff changeset	2733 <h4 heading><a name="Number.float" href="#Number.double"><code>Number.float (x)</code></a></h4>
60599adc27b8 add lucene search options Franklin Schmidt <fschmidt@gmail.com> parents: 1327 diff changeset	2734 <p>
60599adc27b8 add lucene search options Franklin Schmidt <fschmidt@gmail.com> parents: 1327 diff changeset	2735 Returns <code>x</code> as a float.
60599adc27b8 add lucene search options Franklin Schmidt <fschmidt@gmail.com> parents: 1327 diff changeset	2736
60599adc27b8 add lucene search options Franklin Schmidt <fschmidt@gmail.com> parents: 1327 diff changeset	2737
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2738 <h4 heading><a name="Number.integer" href="#Number.integer"><code>Number.integer (x)</code></a></h4>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2739 <p>
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2740 If the value <code>x</code> is convertible to an integer,
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2741 returns that integer.
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2742 Otherwise throws an error.
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2743
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2744
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2745 <h4 heading><a name="Number.long" href="#Number.long"><code>Number.long (x)</code></a></h4>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2746 <p>
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2747 If the value <code>x</code> is convertible to an long,
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2748 returns that long.
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2749 Otherwise throws an error.
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2750
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2751
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2752 <h4 heading><a name="Number.long_to_string" href="#Number.long_to_string"><code>Number.long_to_string (i, radix)</code></a></h4>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2753 <p>
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2754 Converts long value <code>i</code> to a string by calling <code><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Long.html#toString(long,%20int)">Long.toString</a></code>.
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2755
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2756
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2757 <h4 heading><a name="Number.type" href="#Number.type"><code>Number.type (x)</code></a></h4>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2758 <p>
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2759 Returns a string for the numeric type of <code>x</code>. Possible return values include "<code>integer</code>", "<code>long</code>", "<code>double</code>", and "<code>float</code>".
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2760
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2761
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2762
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2763
1327 b29eefad2111 website - improve docs Franklin Schmidt <fschmidt@gmail.com> parents: 1326 diff changeset	2764 <h3 heading><a name="math_lib" href="#math_lib">Mathematical Functions</a></h3>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2765
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2766 <p>
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2767 Include this library by:
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2768
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2769 <pre>
693 ca169567ce07 module URIs must now include ".luan" Franklin Schmidt <fschmidt@gmail.com> parents: 685 diff changeset	2770 local Math = require "luan:Math.luan"
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2771 </pre>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2772
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2773 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2774 This library provides basic mathematical functions.
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2775 It provides all its functions and constants inside the table <code>Math</code>.
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2776
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2777
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2778 <h4 heading><a name="Math.abs" href="#Math.abs"><code>Math.abs (x)</code></a></h4>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2779
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2780 <p>
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2781 Returns the absolute value of <code>x</code>.
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2782
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2783
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2784
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2785 <h4 heading><a name="Math.acos" href="#Math.acos"><code>Math.acos (x)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2786
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2787 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2788 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	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
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2793 <h4 heading><a name="Math.asin" href="#Math.asin"><code>Math.asin (x)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2794
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2795 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2796 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	2797
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2798
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2799
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2800
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2801 <h4 heading><a name="Math.atan" href="#Math.atan"><code>Math.atan (y, x)</code></a></h4>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2802
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2803 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2804 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	2805 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	2806 quadrant of the result.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2807 (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	2808
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2809
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2810
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2811
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2812 <h4 heading><a name="Math.ceil" href="#Math.ceil"><code>Math.ceil (x)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2813
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2814 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2815 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	2816
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2817
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2818
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2819
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2820 <h4 heading><a name="Math.cos" href="#Math.cos"><code>Math.cos (x)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2821
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2822 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2823 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	2824
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2825
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2826
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2827
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2828 <h4 heading><a name="Math.deg" href="#Math.deg"><code>Math.deg (x)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2829
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2830 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2831 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	2832
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
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2836 <h4 heading><a name="Math.exp" href="#Math.exp"><code>Math.exp (x)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2837
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2838 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2839 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	2840 (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	2841
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2842
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
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2845 <h4 heading><a name="Math.floor" href="#Math.floor"><code>Math.floor (x)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2846
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2847 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2848 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	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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2852
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2853 <h4 heading><a name="Math.fmod" href="#Math.fmod"><code>Math.fmod (x, y)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	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 the remainder of the division of <code>x</code> by <code>y</code>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2857 that rounds the quotient towards zero.
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2858
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2859
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2860
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2861
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2862 <h4 heading><a name="Math.huge" href="#Math.huge"><code>Math.huge</code></a></h4>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2863
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2864 <p>
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2865 A value larger than any other numerical value.
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2866
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2867
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2868
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2869
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2870 <h4 heading><a name="Math.log" href="#Math.log"><code>Math.log (x [, base])</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2871
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2872 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2873 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	2874 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	2875 (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	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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2879
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2880 <h4 heading><a name="Math.max" href="#Math.max"><code>Math.max (x, ···)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	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 Returns the argument with the maximum value,
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2884 according to the Lua operator <code><</code>.
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2885
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2886
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2887
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2888
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2889 <h4 heading><a name="Math.max_integer" href="#Math.max_integer"><code>Math.max_integer</code></a></h4>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2890 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2891 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	2892
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2893
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2894
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2895
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2896 <h4 heading><a name="Math.min" href="#Math.min"><code>Math.min (x, ···)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	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 Returns the argument with the minimum value,
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2900 according to the Lua operator <code><</code>.
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2901
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2902
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2903
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2904
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2905 <h4 heading><a name="Math.min_integer" href="#Math.min_integer"><code>Math.min_integer</code></a></h4>
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2906 <p>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2907 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	2908
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
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2912 <h4 heading><a name="Math.modf" href="#Math.modf"><code>Math.modf (x)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2913
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2914 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2915 Returns the integral part of <code>x</code> and the fractional part of <code>x</code>.
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2916
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2917
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2918
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2919
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2920 <h4 heading><a name="Math.pi" href="#Math.pi"><code>Math.pi</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2921
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2922 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2923 The value of <em>π</em>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2924
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2925
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2926
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2927
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2928 <h4 heading><a name="Math.rad" href="#Math.rad"><code>Math.rad (x)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2929
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2930 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2931 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	2932
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2935
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2936 <h4 heading><a name="Math.random" href="#Math.random"><code>Math.random ([m [, n])</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2937
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2938
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2939 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2940 When called without arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2941 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	2942 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	2943 When called with two integers <code>m</code> and <code>n</code>,
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2944 <code>Math.random</code> returns a pseudo-random integer
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2945 with uniform distribution in the range <em>[m, n]</em>.
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2946 (The value <em>m-n</em> cannot be negative and must fit in a Luan integer.)
90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2947 The call <code>Math.random(n)</code> is equivalent to <code>Math.random(1,n)</code>.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	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 This function is an interface to the underling
566 90b93790c544 Number and Math documentation and minor changes Franklin Schmidt <fschmidt@gmail.com> parents: 565 diff changeset	2952 pseudo-random generator function provided by Java.
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2953 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	2954
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2955
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2956
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2957
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2958 <h4 heading><a name="Math.sin" href="#Math.sin"><code>Math.sin (x)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	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 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	2962
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2963
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
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2966 <h4 heading><a name="Math.sqrt" href="#Math.sqrt"><code>Math.sqrt (x)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2967
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2968 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2969 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	2970 (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	2971
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2972
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
642 c4216a583de4 add links to functions in manual Franklin Schmidt <fschmidt@gmail.com> parents: 629 diff changeset	2975 <h4 heading><a name="Math.tan" href="#Math.tan"><code>Math.tan (x)</code></a></h4>
371 e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2976
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2977 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2978 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	2979
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2980
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2983
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2984
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2985
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2986
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2987 <h2>6.8 – <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	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 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	2991 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	2992 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	2993 default output file,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2994 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	2995 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	2996
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2997
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2998 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	2999 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	3000 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	3001 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	3002 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	3003 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	3004
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3005
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3006 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3007 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	3008 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	3009 <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	3010 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	3011
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3012
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3013 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3014 Unless otherwise stated,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3015 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	3016 (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	3017 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	3018 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	3019 On non-POSIX systems,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3020 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	3021 in case of errors
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3022 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	3023 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	3024
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3025
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3026 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3027 <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	3028
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3029
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3030 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3031 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	3032 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	3033
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3034
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 <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	3039
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3040
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3041 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3042 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	3043
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3044
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3045
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3048 <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	3049
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3050
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3051 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3052 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	3053 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	3054 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	3055 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	3056 When called without parameters,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3057 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	3058
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3059
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3060 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3061 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	3062 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	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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3066
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3067 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3068 <hr><h3><a name="pdf-io.lines"><code>io.lines ([filename ···])</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3069
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3070
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3071 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3072 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	3073 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	3074 works like <code>file:lines(···)</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	3075 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	3076 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	3077
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3078
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3079 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3080 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	3081 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	3082 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	3083 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	3084
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3085
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3086 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3087 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	3088 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	3089
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3090
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3091
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3092
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3093 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3094 <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	3095
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3096
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3097 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3098 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	3099 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	3100 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	3101 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	3102
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3105 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	3106
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3107 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3108 <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	3109 <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	3110 <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	3111 <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	3112 <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	3113 <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	3114 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	3115 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3116 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	3117 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	3118
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3119
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3120
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3121
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3122 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3123 <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	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 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	3128
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3129
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3130
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3131
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3132 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3133 <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	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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3137 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	3138 on all platforms.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3139
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3140
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3141 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3142 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	3143 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	3144 (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	3145 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	3146 (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	3147
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3148
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3149
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3150
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3151 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3152 <hr><h3><a name="pdf-io.read"><code>io.read (···)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3153
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3154
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3155 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3156 Equivalent to <code>io.input():read(···)</code>.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3159
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3160
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3161 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3162 <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	3163
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3164
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3165 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3166 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	3167 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	3168 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	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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3172
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3173 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3174 <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	3175
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3176
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3177 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3178 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	3179 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	3180 <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	3181 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	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-io.write"><code>io.write (···)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3188
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3189
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3190 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3191 Equivalent to <code>io.output():write(···)</code>.
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3197 <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	3198
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3199
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3200 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3201 Closes <code>file</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3202 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	3203 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	3204 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	3205
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3206
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3207 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3208 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	3209 <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	3210 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	3211
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3212
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3213
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3216 <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	3217
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3218
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3219 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3220 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	3221
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
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3226 <hr><h3><a name="pdf-file:lines"><code>file:lines (···)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3227
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3230 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	3231 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	3232 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	3233 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	3234 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	3235 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	3236
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3237 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3238 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	3239 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3240 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	3241 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	3242 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	3243 when the loop ends.
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3246 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3247 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	3248 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	3249
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3250
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3251
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3252
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3253 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3254 <hr><h3><a name="pdf-file:read"><code>file:read (···)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3255
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3256
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3257 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3258 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	3259 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	3260 For each format,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3261 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	3262 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	3263 (In this latter case,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3264 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	3265 When called without formats,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3266 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	3267 (see below).
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 available formats are
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3272
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3273 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3274
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3275 <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	3276 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	3277 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	3278 (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	3279 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	3280 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	3281 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	3282 (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	3283 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	3284 </li>
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 <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	3287 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	3288 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3289
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3290 <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	3291 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	3292 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	3293 </li>
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 <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	3296 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	3297 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	3298 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	3299 </li>
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><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	3302 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	3303 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	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><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	3307 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	3308 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	3309 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	3310 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	3311 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	3312 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3313
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3314 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3315 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	3316
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3319
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3320 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3321 <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	3322
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3323
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3324 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3325 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	3326 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	3327 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	3328 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	3329
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3330 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3331 <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	3332 <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	3333 <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	3334 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3335 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	3336 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	3337 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	3338 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	3339
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3340
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3341 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3342 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	3343 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	3344 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	3345 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	3346 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	3347 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	3348 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	3349 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	3350
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3351
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3352
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3353
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3354 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3355 <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	3356
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3359 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	3360 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	3361
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3362 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3363
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3364 <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	3365 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	3366 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3367
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3368 <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	3369 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	3370 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	3371 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	3372 </li>
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 <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	3375 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	3376 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	3377 (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	3378 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3379
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3380 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3381 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	3382 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	3383 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	3384
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3385
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3386
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3387
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3388 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3389 <hr><h3><a name="pdf-file:write"><code>file:write (···)</code></a></h3>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3390
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3391
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3392 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3393 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	3394 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	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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3398 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	3399 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	3400
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3401
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3404
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3405
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3406
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3407 <h2>6.9 – <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	3408
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3409 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3410 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	3411
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3412
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3413 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3414 <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	3415
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3416
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3417 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3418 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	3419 used by the program.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3420
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3421
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3422
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3423
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3424 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3425 <hr><h3><a name="pdf-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	3426
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3427
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3428 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3429 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	3430 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	3431
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3432
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3433 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3434 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	3435 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	3436 (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	3437 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	3438
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3439
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3440 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3441 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	3442 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	3443 After this optional character,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3444 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	3445 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	3446 <code>year</code> (four digits), <code>month</code> (1–12), <code>day</code> (1–31),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3447 <code>hour</code> (0–23), <code>min</code> (0–59), <code>sec</code> (0–61),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3448 <code>wday</code> (weekday, Sunday is 1),
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3449 <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	3450 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	3451 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	3452 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	3453
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3454
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3455 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3456 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	3457 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	3458 formatted according to the same rules as the ISO 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	3459
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3462 When called without arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3463 <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	3464 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	3465 (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	3466
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3469 On non-POSIX systems,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3470 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	3471 because of its reliance on C function <code>gmtime</code> and C function <code>localtime</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3472
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3473
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3474
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3475
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3476 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3477 <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	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 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	3482 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	3483 (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	3484 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	3485 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	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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3491 <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	3492
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3493
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3494 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3495 This function is equivalent to the ISO 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	3496 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	3497 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	3498 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	3499 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	3500 After this first result
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3501 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	3502 as follows:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3503
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3504 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3505
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3506 <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	3507 the command terminated normally;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3508 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	3509 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3510
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3511 <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	3512 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	3513 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	3514 </li>
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 </ul>
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3519 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	3520 <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	3521
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3522
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3523
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3524
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3525 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3526 <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	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 Calls the ISO 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	3531 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	3532 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	3533 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	3534 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	3535 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	3536 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	3537 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	3538
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3539
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3540 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3541 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	3542 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	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-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	3549
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3550
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3551 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3552 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	3553 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	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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3558 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3559 <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	3560
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3561
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3562 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3563 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	3564 with the given name.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3565 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	3566 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	3567
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3568
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3569
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3570
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3571 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3572 <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	3573
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3574
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3575 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3576 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	3577 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	3578 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	3579
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3580
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3581
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3582
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3583 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3584 <hr><h3><a name="pdf-os.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	3585
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3586
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3587 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3588 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	3589 <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	3590 <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	3591 <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	3592 <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	3593 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	3594 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	3595 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	3596
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3597
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3598 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3599 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	3600 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	3601 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	3602 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	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 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	3607 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	3608 for the given category.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3609
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3610
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3611 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3612 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	3613 because of its reliance on C function <code>setlocale</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3614
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3615
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3616
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3617
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3618 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3619 <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	3620
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3621
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3622 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3623 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	3624 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	3625 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	3626 and may have fields
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3627 <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	3628 <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	3629 <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	3630 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	3631 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	3632
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3633
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3634 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3635 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	3636 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	3637 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	3638 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	3639 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	3640 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	3641 <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	3642
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3643
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3644
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3647 <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	3648
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3649
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3650 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3651 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	3652 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	3653 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	3654 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	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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3658 On POSIX systems,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3659 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	3660 to avoid security risks.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3661 (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	3662 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	3663 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	3664 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	3665
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3666
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3667 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3668 When possible,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3669 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	3670 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	3671
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3672
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3676
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3677
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3678 <h2>6.10 – <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	3679
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3680 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3681 This library provides
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3682 the functionality of the debug interface (<a href="#4.9">§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	3683 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	3684 Several of its functions
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3685 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	3686 (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	3687 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	3688 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	3689 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	3690 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	3691 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	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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3695 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	3696 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	3697 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	3698 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	3699 thread to operate over.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3700 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	3701
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3702
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3703 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3704 <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	3705
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3706
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3707 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3708 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	3709 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	3710 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	3711 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	3712 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	3713 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	3714 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	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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3718 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	3719 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	3720
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3724 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3725 <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	3726
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3727
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3728 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3729 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	3730 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	3731 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	3732 (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	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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3738 <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	3739
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3740
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3741 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3742 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	3743 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	3744 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	3745 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	3746 of the given thread:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3747 level 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	3748 level 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	3749 (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	3750 and so on.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3751 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	3752 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	3753
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3756 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	3757 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	3758 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	3759 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	3760 If present,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3761 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	3762 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	3763 If present,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3764 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	3765 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	3766 valid lines.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3767
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3770 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	3771 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	3772 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	3773 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	3774 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	3775 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	3776
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3777
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3781 <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	3782
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3783
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3784 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3785 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	3786 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	3787 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	3788 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	3789
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3790
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3791 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3792 The first parameter or local variable has index 1, and so on,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3793 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	3794 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	3795 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	3796 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	3797 -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	3798 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	3799 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	3800 (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	3801
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3802
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3803 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3804 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	3805 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	3806 (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	3807 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	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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3811 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	3812 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	3813
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3814
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3815
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3816
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3817 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3818 <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	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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3822 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	3823 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	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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3827
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3828 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3829 <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	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 Returns the registry table (see <a href="#4.5">§4.5</a>).
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3837
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3838 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3839 <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	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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3843 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	3844 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	3845 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	3846
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3847
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3848 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3849 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	3850 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	3851 (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	3852
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3853
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3854
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3857 <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	3858
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3859
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3860 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3861 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	3862 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	3863 returns <b>nil</b>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3864
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3865
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 <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	3870
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3871
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3872 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3873 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	3874 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	3875 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	3876 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	3877 with the given meaning:
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 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3880 <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	3881 <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	3882 <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	3883 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3884 Moreover,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3885 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	3886 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	3887
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3888
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3889 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3890 When called without arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3891 <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	3892
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3893
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3894 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3895 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	3896 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	3897 <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	3898 <code>"return"</code>,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3899 <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	3900 For line events,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3901 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	3902 Inside a hook,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3903 you can call <code>getinfo</code> with level 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	3904 the running function
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3905 (level 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	3906 and level 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	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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3910
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3911 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3912 <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	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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3916 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	3917 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	3918 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	3919 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	3920 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	3921 (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	3922 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	3923
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3924
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3925 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3926 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	3927 variable indices and names.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3928
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3929
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3930
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3933 <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	3934
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3935
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3936 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3937 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	3938 (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	3939 Returns <code>value</code>.
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-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	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 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	3950 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	3951 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	3952 with the given index.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3953 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	3954
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3955
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 <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	3960
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3961
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3962 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3963 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	3964 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	3965 <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	3966
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3967
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3968 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3969 Returns <code>udata</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3970
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3971
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3972
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3975 <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	3976
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3977
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3978 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3979 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	3980 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	3981 Otherwise,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3982 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	3983 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	3984 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	3985 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	3986 to start the traceback
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3987 (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	3988
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3989
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3990
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3991
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3992 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3993 <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	3994
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	3997 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	3998 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	3999 from the given function.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4000
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4003 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	4004 closures share upvalues.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4005 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	4006 (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	4007 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	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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4011
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4012 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4013 <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	4014
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4015
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4016 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4017 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	4018 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	4019
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4020
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4021
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4025
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4026 <h1>7 – <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	4027
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4028 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4029 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	4030 to be embedded in a host C program,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4031 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	4032 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	4033 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	4034 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	4035 The standalone interpreter includes
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4036 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	4037 Its usage is:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4038
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4039 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4040 lua [options] [script [args]]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4041 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4042 The options are:
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 <ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4045 <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	4046 <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	4047 <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	4048 <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	4049 <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	4050 <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	4051 <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	4052 </ul><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4053 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	4054 When called without arguments,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4055 <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	4056 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	4057 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	4058
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4059
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4060 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4061 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	4062 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	4063 (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	4064 before running any argument.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4065 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	4066 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	4067 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	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 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	4072 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	4073 Lua also ignores
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4074 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	4075 setting the values of
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4076 <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	4077 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	4078
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4079
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4080 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4081 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	4082 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	4083
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4084 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4085 $ 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	4086 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4087 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	4088 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	4089 (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	4090
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4091
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4092 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4093 Before running any code,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4094 <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	4095 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	4096 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	4097 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	4098 and so on.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4099 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	4100 (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	4101 go to negative indices.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4102 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	4103
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4104 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4105 $ 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	4106 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4107 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	4108
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4109 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4110 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	4111 [0] = "b.lua",
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4112 [1] = "t1", [2] = "t2" }
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4113 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4114 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	4115 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	4116 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	4117 For instance, the call
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 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4120 $ 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	4121 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4122 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	4123 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	4124 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	4125 <code>arg[1]</code>, ···, <code>arg[#arg]</code>.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4126 (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	4127 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	4128
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4129
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4130 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4131 In interactive mode,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4132 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	4133 After reading a line,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4134 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	4135 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	4136 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	4137 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	4138 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	4139 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	4140
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4143 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	4144 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	4145 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	4146 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	4147 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	4148 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	4149 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	4150
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4151
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4152 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4153 When finishing normally,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4154 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	4155 (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	4156 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	4157 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	4158
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4159
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4160 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4161 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	4162 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	4163 the standalone interpreter skips
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4164 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	4165 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	4166 by using <code>chmod +x</code> and the <code>#!</code> form,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4167 as in
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 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4170 #!/usr/local/bin/lua
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4171 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4172 (Of course,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4173 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	4174 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	4175 then
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4176
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4177 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4178 #!/usr/bin/env lua
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4179 </pre><p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4180 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	4181
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4182
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4183
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4184 <h1>8 – <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	4185
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4186 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4187 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	4188 from Lua 5.2 to Lua 5.3.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4189 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	4190 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	4191 However,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4192 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	4193
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4194
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4195 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4196 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	4197 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	4198 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	4199 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	4200 Therefore,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4201 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	4202 different Lua versions.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4203 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	4204 using a new version.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4205
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 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4208 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	4209 of precompiled chunks;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4210 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	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 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	4215 change between versions.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4216
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4217
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4218
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4219 <h2>8.1 – <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	4220 <ul>
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 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4223 The main difference between Lua 5.2 and Lua 5.3 is the
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4224 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	4225 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	4226 some computations
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4227 (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	4228 can give different results.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4229
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4230
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4231 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4232 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	4233 (in Lua 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	4234 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	4235 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	4236 (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	4237 for an occasional incompatibility;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4238 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	4239 For good programming,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4240 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	4241 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	4242 </li>
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 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4245 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	4246 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	4247 (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	4248 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	4249 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	4250 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	4251
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4252
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4253 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4254 (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	4255 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	4256 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	4257 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4258
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4259 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4260 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	4261 (It was an experimental feature in Lua 5.2.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4262 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4263
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4264 </ul>
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4269 <h2>8.2 – <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	4270 <ul>
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 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4273 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	4274 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	4275 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	4276 (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	4277 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	4278 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4279
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4280 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4281 The 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	4282 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	4283 </li>
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 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4286 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	4287 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	4288 </li>
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 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4291 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	4292 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	4293 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4294
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4295 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4296 The 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	4297 <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	4298 <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	4299 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	4300 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	4301 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	4302 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	4303 For the other operations,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4304 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	4305 implement them in Lua.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4306 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4307
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4308 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4309 The 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	4310 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	4311 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	4312 (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	4313 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	4314 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	4315 (Lua 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	4316 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	4317 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4318
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4319 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4320
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4321
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 <h2>8.3 – <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	4325
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4326
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4327 <ul>
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 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4330 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	4331 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	4332 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	4333 Adapt your code accordingly.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4334 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4335
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4336 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4337 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	4338 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	4339 </li>
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 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4342 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	4343 (<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	4344 <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	4345 were deprecated.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4346 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	4347 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4348
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4349 <li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4350 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	4351 (<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	4352 were deprecated.
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4353 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	4354 (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	4355 </li>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4356
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4357 </ul>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4358
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4359
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4360
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 <h1>9 – <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	4363
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4364 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4365 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	4366 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	4367 {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	4368 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	4369 (For operator precedences, see <a href="#3.4.8">§3.4.8</a>;
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4370 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	4371 Name, Numeral,
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4372 and LiteralString, see <a href="#3.1">§3.1</a>.)
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4373
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4374
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4375
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4376
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4377 <pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4378
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4379 chunk ::= block
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4380
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4381 block ::= {stat} [retstat]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4382
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4383 stat ::= ‘<b>;</b>’ \|
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4384 varlist ‘<b>=</b>’ explist \|
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4385 functioncall \|
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4386 label \|
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4387 <b>break</b> \|
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4388 <b>goto</b> Name \|
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4389 <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	4390 <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	4391 <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	4392 <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	4393 <b>for</b> Name ‘<b>=</b>’ exp ‘<b>,</b>’ exp [‘<b>,</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	4394 <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	4395 <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	4396 <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	4397 <b>local</b> namelist [‘<b>=</b>’ explist]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4398
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4399 retstat ::= <b>return</b> [explist] [‘<b>;</b>’]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4400
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4401 label ::= ‘<b>::</b>’ Name ‘<b>::</b>’
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4402
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4403 funcname ::= Name {‘<b>.</b>’ Name} [‘<b>:</b>’ Name]
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4404
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4405 varlist ::= var {‘<b>,</b>’ var}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4406
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4407 var ::= Name \| prefixexp ‘<b>[</b>’ exp ‘<b>]</b>’ \| prefixexp ‘<b>.</b>’ Name
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4408
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4409 namelist ::= Name {‘<b>,</b>’ Name}
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4410
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4411 explist ::= exp {‘<b>,</b>’ exp}
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 exp ::= <b>nil</b> \| <b>false</b> \| <b>true</b> \| Numeral \| LiteralString \| ‘<b>...</b>’ \| functiondef \|
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4414 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	4415
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4416 prefixexp ::= var \| functioncall \| ‘<b>(</b>’ exp ‘<b>)</b>’
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4417
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4418 functioncall ::= prefixexp args \| prefixexp ‘<b>:</b>’ Name args
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4419
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4420 args ::= ‘<b>(</b>’ [explist] ‘<b>)</b>’ \| tableconstructor \| LiteralString
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4421
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4422 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	4423
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4424 funcbody ::= ‘<b>(</b>’ [parlist] ‘<b>)</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	4425
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4426 parlist ::= namelist [‘<b>,</b>’ ‘<b>...</b>’] \| ‘<b>...</b>’
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4427
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4428 tableconstructor ::= ‘<b>{</b>’ [fieldlist] ‘<b>}</b>’
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 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	4431
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4432 field ::= ‘<b>[</b>’ exp ‘<b>]</b>’ ‘<b>=</b>’ exp \| Name ‘<b>=</b>’ exp \| exp
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 fieldsep ::= ‘<b>,</b>’ \| ‘<b>;</b>’
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 binop ::= ‘<b>+</b>’ \| ‘<b>-</b>’ \| ‘<b>*</b>’ \| ‘<b>/</b>’ \| ‘<b>//</b>’ \| ‘<b>^</b>’ \| ‘<b>%</b>’ \|
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4437 ‘<b>&</b>’ \| ‘<b>~</b>’ \| ‘<b>\|</b>’ \| ‘<b>>></b>’ \| ‘<b><<</b>’ \| ‘<b>..</b>’ \|
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4438 ‘<b><</b>’ \| ‘<b><=</b>’ \| ‘<b>></b>’ \| ‘<b>>=</b>’ \| ‘<b>==</b>’ \| ‘<b>~=</b>’ \|
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4439 <b>and</b> \| <b>or</b>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4440
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4441 unop ::= ‘<b>-</b>’ \| <b>not</b> \| ‘<b>#</b>’ \| ‘<b>~</b>’
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4442
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4443 </pre>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4444
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4445 <p>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4446
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4447
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4448
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4449
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4450
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
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4453
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4454 <HR>
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4455 <SMALL CLASS="footer">
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4456 Last update:
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4457 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	4458 </SMALL>
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 Last change: minor edit
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4461 -->
e01cddba3433 add manual.html as copy of Lua 5.3 Reference Manual Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4462
391 2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 389 diff changeset	4463 </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	4464 </html>

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