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

annotate website/src/diff.html.luan @ 635:c83b8cefd922

better error handling in theme code

author	Franklin Schmidt <fschmidt@gmail.com>
date	Tue, 01 Mar 2016 07:01:58 -0700
parents	b73f005f3735
children	1e4b0bc0202d

rev	line source
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	1 local Io = require "luan:Io"
494 2b9bc97f0439 change luan:web to luan:http Franklin Schmidt <fschmidt@gmail.com> parents: 483 diff changeset	2 local Http = require "luan:http/Http"
387 23d075ce1e48 add website/src/Shared.luan Franklin Schmidt <fschmidt@gmail.com> parents: 386 diff changeset	3 local Shared = require "site:/Shared"
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	4
503 92c3d22745b8 make _ENV optional Franklin Schmidt <fschmidt@gmail.com> parents: 495 diff changeset	5
505 7bc63886d4f2 web page modules now return a function Franklin Schmidt <fschmidt@gmail.com> parents: 503 diff changeset	6 return function()
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	7 Io.stdout = Http.response.text_writer()
391 2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 390 diff changeset	8 %>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 390 diff changeset	9 <html>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 390 diff changeset	10 <head>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 390 diff changeset	11 <title>How Luan differs from Lua</title>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	12 <style>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	13 @import "/site.css";
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	14 </style>
391 2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 390 diff changeset	15 </head>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 390 diff changeset	16 <body>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	17
387 23d075ce1e48 add website/src/Shared.luan Franklin Schmidt <fschmidt@gmail.com> parents: 386 diff changeset	18 <% Shared.header() %>
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	19 <h1>How Luan differs from Lua</h1>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	20
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	21 <p>This document explains how Luan differs from <a href="http://www.lua.org">Lua</a> as described in the <a href="http://www.lua.org/manual/5.3/">Lua 5.3 Reference Manual</a>.</p>
372 f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 370 diff changeset	22
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	23 <hr/>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	24
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	25 <h2>Contents</h2>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	26
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	27 <div contents><a href="#intro">Introduction</a></div>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	28
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	29 <div contents>
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	30 <a href="#basic">Basic Concepts</a>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	31 <ul>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	32 <li><a href="#types">Values and Types</a></li>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	33 <li><a href="#env">Environments</a></li>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	34 <li><a href="#error">Error Handling</a></li>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	35 <li><a href="#meta">Metatables and Metamethods</a></li>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	36 <li><a href="#gc">Garbage Collection</a></li>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	37 <li><a href="#coroutines">Coroutines</a></li>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	38 </ul>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	39 </div>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	40
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	41 <div contents>
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	42 <a href="#lang">The Language</a>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	43 <ul>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	44 <li><a href="#lex">Lexical Conventions</a></li>
512 d96944467ffc update documentation for luan changes Franklin Schmidt <fschmidt@gmail.com> parents: 505 diff changeset	45 <li><a href="#vars">Variables</a></li>
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	46 <li>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	47 <a href="#stmt">Statements</a>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	48 <ul>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	49 <li><a href="#control">Control Structures</a></li>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	50 <li><a href="#for">For Statement</a></li>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	51 <li><a href="#logical">Logical Statements</a></li>
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	52 <li><a href="#template_stmt">Template Statements</a></li>
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	53 </ul>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	54 </li>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	55 <li>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	56 <a href="#expr">Expressions</a>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	57 <ul>
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	58 <li><a href="#conversions">Coercions and Conversions</a></li>
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	59 <li><a href="#bit">Bitwise Operators</a></li>
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	60 <li><a href="#logical_ops">Logical Operators</a></li>
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	61 <li><a href="#concatenation">Concatenation</a></li>
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	62 <li><a href="#fn_calls">Function Calls</a></li>
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	63 <li><a href="#template_expr">Template Expressions</a></li>
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	64 </ul>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	65 </li>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	66 </ul>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	67 </div>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	68
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	69 <hr/>
db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	70
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	71 <h2 heading><a name="intro">Introduction</a></h2>
372 f08cefa4594c start editing manual Franklin Schmidt <fschmidt@gmail.com> parents: 370 diff changeset	72
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	73 <p>Lua is one of the simplest languages available, but Luan is even simpler. This means Luan removes more than it adds. Most of what is added is added in the library, not in the language itself.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	74
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	75 <p>Luan is implemented in Java and is tightly integrated with Java. This makes it an excellent scripting language for Java.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	76
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	77 <h2 heading><a name="basic">Basic Concepts</a></h2>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	78
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	79 <h3 heading><a name="types">Values and Types</a></h3>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	80
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	81 <p>Luan does not have the Lua <em>thread</em> type. Luan adds a <em>binary</em> type that Lua doesn't have. This is because Lua strings can represent binary while Luan strings cannot.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	82
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	83 <p>The Luan <em>Nil</em> type is implemented as the Java <em>null</em>. The Luan <em>Boolean</em> type is implemented as the Java <em>Boolean</em> type. The Luan <em>Number</em> type is implemented as the Java <em>Number</em> type. The Luan <em>String</em> type is implemented as the Java <em>String</em> type. Actual numbers may be any subclass of the Java <em>Number</em> class.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	84
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	85 <p>Luan functions may be written in Luan or may be wrappers around native Java methods. Any Java method may be called as a Luan function.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	86
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	87 <p>The Luan <em>java</em> type is a replacement for Lua's <em>userdata</em>. A Luan <em>java</em> value is nothing more than a Java object that doesn't fall into one of the other recognized types.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	88
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	89 <p>The Luan <em>binary</em> type is the Java <em>byte[ ]</em> type which is an array of bytes.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	90
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	91 <p>The Luan <em>table</em> type is just like its Lua equivalent, but implemented in Java.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	92
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	93 <h3 heading><a name="env">Environments</a></h3>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	94
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	95 <p>Luan has no global environment at all, no <code>_G</code>. By default, Luan doesn't define <code>_ENV</code> either, but if you define it as a local table in a chunk, then it acts like it does in Lua. When <code>_ENV</code> isn't defined, there are no global variables and an unrecognized variable name produces a compile error.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	96
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	97 <p>Every module is initialized with two local functions: <code>require</code> and <code>java</code>. The module then uses these functions to get access to whatever else it needs.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	98
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	99 <h3 heading><a name="error">Error Handling</a></h3>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	100
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	101 <p>Luan has the functions <code>error</code> and <code>pcall</code> but does not have <code>xpcall</code>. Luan adds the function <code>try</code> which looks and acts like try-catch blocks in other languages. Luan errors are implemented as an error table, not as a message object.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	102
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	103 <h3 heading><a name="meta">Metatables and Metamethods</a></h3>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	104
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	105 <p>Luan only has metatable for tables, not for other types.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	106
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	107 <h3 heading><a name="gc">Garbage Collection</a></h3>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	108
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	109 <p>Luan uses Java garbage collection. Luan has no special garbage collection methods.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	110
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	111 <p>Luan does not yet have weak tables but this will be added.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	112
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	113 <h3 heading><a name="coroutines">Coroutines</a></h3>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	114
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	115 <p>Luan does not have coroutines. Coroutines is a complex concept that isn't needed in a simple language, so it was left out.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	116
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	117 <h2 heading><a name="lang">The Language</a></h2>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	118
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	119 <h3 heading><a name="lex">Lexical Conventions</a></h3>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	120
604 b73f005f3735 table constructor now uses end_of_line as a delimiter Franklin Schmidt <fschmidt@gmail.com> parents: 562 diff changeset	121 <p>Unlike Lua, Luan generally considers the end of a line to be the end of a statement. This catches errors and encourages readability. The exception to this is in paranthesis <em>(...)</em> where the end of line is treated as white space.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	122
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	123 <p>Luan has exactly the same set of keywords as Lua and has the same other lexical conventions.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	124
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	125 <h3 heading><a name="vars">Variables</a></h3>
512 d96944467ffc update documentation for luan changes Franklin Schmidt <fschmidt@gmail.com> parents: 505 diff changeset	126
d96944467ffc update documentation for luan changes Franklin Schmidt <fschmidt@gmail.com> parents: 505 diff changeset	127 <p>
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	128 By default, there are no global variables and an undefined variable produces a compile error. To enable global variables, one must define <code>_ENV</code>. Avoiding global variables makes it much easier to catch errors at compile time.
512 d96944467ffc update documentation for luan changes Franklin Schmidt <fschmidt@gmail.com> parents: 505 diff changeset	129
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	130 <h3 heading><a name="stmt">Statements</a></h3>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	131
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	132 <p>Most statements in Luan are the same as Lua. Only those statements that differ will be listed here.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	133
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	134 <h4 heading><a name="control">Control Structures</a></h4>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	135
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	136 <p>The Luan <b>if</b>, <b>while</b>, and <b>repeat</b> statement are the same as in Lua except that the condition expression must return a boolean value. Any other value type will produce an error. This helps catch errors and makes code more readable.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	137
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	138 <p>Luan does not have a <b>goto</b> statement.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	139
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	140 <h4 heading><a name="for">For Statement</a></h4>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	141
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	142 <p>Luan has no numeric <b>for</b> statement. Luan only has generic <b>for</b> statement. Instead of the numeric <b>for</b> statement, Luan uses the <code>range</code> function in a generic <b>for</b> statement like this:</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	143
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	144 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	145 for i in range(from,to,step) do <em>block</em> end
7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	146 </pre>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	147
468 9b51e2413cab documentation Franklin Schmidt <fschmidt@gmail.com> parents: 465 diff changeset	148 <p>The Luan generic <b>for</b> statement is simpler than the Lua version because Luan only uses an expression, not an explist. So a <b>for</b> statement like:</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	149
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	150 <pre>
390 bfbbce690bba minor Franklin Schmidt <fschmidt@gmail.com> parents: 389 diff changeset	151 for var_1, ···, var_n in exp do block end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	152 </pre>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	153
389 497d4ef0a89f documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 387 diff changeset	154 <p>is equivalent to the code:</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	155
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	156 <pre>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	157 do
38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	158 local f = exp
38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	159 while true do
390 bfbbce690bba minor Franklin Schmidt <fschmidt@gmail.com> parents: 389 diff changeset	160 local var_1, ···, var_n = f()
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	161 if var_1 == nil then break end
38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	162 block
38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	163 end
38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	164 end
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	165 </pre>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	166
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	167 <h4 heading><a name="logical">Logical Statements</a></h4>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	168
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	169 <p>Unlike Lua, Luan allows <b>or</b> and <b>and</b> expressions to be stand-alone statements. This is useful in cases like this:</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	170
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	171 <pre>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	172 x==5 or error "x should be 5"
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	173 </pre>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	174
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	175 <h4 heading><a name="template_stmt">Template Statements</a></h4>
367 c207be7cf45d more documentation Franklin Schmidt <fschmidt@gmail.com> parents: 354 diff changeset	176
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	177 <p>Template statements are a Luan addition that don't exist in Lua. See <a href="manual.html#template_stmt">Template Statements</a> in the Luan Reference Manual.</p>
367 c207be7cf45d more documentation Franklin Schmidt <fschmidt@gmail.com> parents: 354 diff changeset	178
c207be7cf45d more documentation Franklin Schmidt <fschmidt@gmail.com> parents: 354 diff changeset	179
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	180 <h3 heading><a name="expr">Expressions</a></h3>
367 c207be7cf45d more documentation Franklin Schmidt <fschmidt@gmail.com> parents: 354 diff changeset	181
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	182 <h4 heading><a name="conversions">Coercions and Conversions</a></h4>
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	183
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	184 <p>Unlike Lua, Luan does not do automatic conversions of strings to numbers.</p>
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	185
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	186 <h4 heading><a name="bit">Bitwise Operators</a></h4>
367 c207be7cf45d more documentation Franklin Schmidt <fschmidt@gmail.com> parents: 354 diff changeset	187
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	188 <p>Bitwise operators appear to be a new addition to Lua 5.3 and didn't exist in Lua 5.2. Luan does not support bitwise operators, but these can be added if there is a need.</p>
367 c207be7cf45d more documentation Franklin Schmidt <fschmidt@gmail.com> parents: 354 diff changeset	189
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	190 <h4 heading><a name="logical_ops">Logical Operators</a></h4>
367 c207be7cf45d more documentation Franklin Schmidt <fschmidt@gmail.com> parents: 354 diff changeset	191
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	192 <p>The only change in Luan is that <b>not</b> must take a boolean argument. This helps catch errors and makes code more readable.</p>
367 c207be7cf45d more documentation Franklin Schmidt <fschmidt@gmail.com> parents: 354 diff changeset	193
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	194 <h4 heading><a name="concatenation">Concatenation</a></h4>
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	195
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	196 <p>Unlike Lua, Luan converts all concatenation operands to strings.
47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	197
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	198 <h4 heading><a name="fn_calls">Function Calls</a></h4>
367 c207be7cf45d more documentation Franklin Schmidt <fschmidt@gmail.com> parents: 354 diff changeset	199
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	200 <p>Luan does not support Lua's <code>v:name(args)</code> style object-oriented function call. Object oriented programming is done in Luan using closures, so this feature is not needed.</p>
367 c207be7cf45d more documentation Franklin Schmidt <fschmidt@gmail.com> parents: 354 diff changeset	201
562 7cc9d4a53d3b remove SimplyHTML from documentation Franklin Schmidt <fschmidt@gmail.com> parents: 513 diff changeset	202 <h4 heading><a name="template_expr">Template Expressions</a></h4>
367 c207be7cf45d more documentation Franklin Schmidt <fschmidt@gmail.com> parents: 354 diff changeset	203
465 47c7de1f2322 documentation work Franklin Schmidt <fschmidt@gmail.com> parents: 464 diff changeset	204 <p>Template expressions are a Luan addition that don't exist in Lua. See <a href="manual.html#template_expr">Template Expressions</a> in the Luan Reference Manual.</p>
353 38c19ecc384d start documentation Franklin Schmidt <fschmidt@gmail.com> parents: diff changeset	205
391 2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 390 diff changeset	206 </body>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 390 diff changeset	207 </html>
2f5cc9c2cbf0 replace Html.simply_html_page with simply_html_head and simply_html_body_bottom Franklin Schmidt <fschmidt@gmail.com> parents: 390 diff changeset	208 <%
386 db23f654f87d make all of website use luan Franklin Schmidt <fschmidt@gmail.com> parents: 372 diff changeset	209 end

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