annotate website/src/diff.html @ 1362:77f2d091f17f

minor - SaneQueryParser
author Franklin Schmidt <fschmidt@gmail.com>
date Sun, 26 May 2019 12:42:08 -0600
parents b29eefad2111
children f5368cd8c056
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
1216
5dbb552075ff doctype
Franklin Schmidt <fschmidt@gmail.com>
parents: 1092
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: 390
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: 390
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: 390
diff changeset
4 <title>How Luan differs from Lua</title>
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
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: 513
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: 390
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: 390
diff changeset
9 <body>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
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>
1324
1660136ac451 website - remove Shared.luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 1216
diff changeset
15
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
16 <h1><a href="diff.html">How Luan differs from Lua</a></h1>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
17
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
18 <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
19
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
20 <hr/>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
21
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
22 <h2>Contents</h2>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
23
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
24 <div contents><a href="#intro">Introduction</a></div>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
25
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
26 <div contents>
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
27 <a href="#basic">Basic Concepts</a>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
28 <ul>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
29 <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
30 <li><a href="#env">Environments</a></li>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
31 <li><a href="#error">Error Handling</a></li>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
32 <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
33 <li><a href="#gc">Garbage Collection</a></li>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
34 <li><a href="#coroutines">Coroutines</a></li>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
35 </ul>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
36 </div>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
37
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
38 <div contents>
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
39 <a href="#lang">The Language</a>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
40 <ul>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
41 <li><a href="#lex">Lexical Conventions</a></li>
512
d96944467ffc update documentation for luan changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 505
diff changeset
42 <li><a href="#vars">Variables</a></li>
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
43 <li>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
44 <a href="#stmt">Statements</a>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
45 <ul>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
46 <li><a href="#control">Control Structures</a></li>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
47 <li><a href="#for">For Statement</a></li>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
48 <li><a href="#logical">Logical Statements</a></li>
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
49 <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
50 </ul>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
51 </li>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
52 <li>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
53 <a href="#expr">Expressions</a>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
54 <ul>
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
55 <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
56 <li><a href="#bit">Bitwise Operators</a></li>
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
57 <li><a href="#logical_ops">Logical Operators</a></li>
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
58 <li><a href="#concatenation">Concatenation</a></li>
686
33f1b4ad2c9d more documentation fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 685
diff changeset
59 <li><a href="#constructors">Table Constructors</a></li>
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
60 <li><a href="#fn_calls">Function Calls</a></li>
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
61 <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
62 </ul>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
63 </li>
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 </div>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
66
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
67 <hr/>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
68
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
69 <h2 heading><a name="intro" href="#intro">Introduction</a></h2>
372
f08cefa4594c start editing manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 370
diff changeset
70
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
71 <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
72
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
73 <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
74
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
75 <h2 heading><a name="basic" href="#basic">Basic Concepts</a></h2>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
76
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
77 <h3 heading><a name="types" href="#types">Values and Types</a></h3>
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 <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
80
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
81 <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
82
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
83 <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
84
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
85 <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
86
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
87 <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
88
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
89 <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
90
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
91 <h3 heading><a name="env" href="#env">Environments</a></h3>
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 <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
94
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
95 <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
96
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
97 <h3 heading><a name="error" href="#error">Error Handling</a></h3>
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 <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
100
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
101 <h3 heading><a name="meta" href="#meta">Metatables and Metamethods</a></h3>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
102
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
103 <p>Luan only has metatable for tables, not for other types.</p>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
104
685
1e4b0bc0202d update documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 604
diff changeset
105 <p>Luan does not support the <b>call</b> metamethod. There is nothing that one can do with the <b>call</b> metamethod that can't be done more cleanly with closures, so this was left out.</p>
1e4b0bc0202d update documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 604
diff changeset
106
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
107 <h3 heading><a name="gc" href="#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
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
113 <h3 heading><a name="coroutines" href="#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
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
117 <h2 heading><a name="lang" href="#lang">The Language</a></h2>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
118
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
119 <h3 heading><a name="lex" href="#lex">Lexical Conventions</a></h3>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
120
685
1e4b0bc0202d update documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 604
diff changeset
121 <p>Unlike Lua, 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.</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
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
125 <h3 heading><a name="vars" href="#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
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
130 <h3 heading><a name="stmt" href="#stmt">Statements</a></h3>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
131
1092
a26fbde7ee28 documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 1090
diff changeset
132 <p>Luan adds the block terminators <b>end_do</b>, <b>end_for</b>, <b>end_function</b>, <b>end_if</b>, and <b>end_while</b>. These can be used to end the appropriate block type, but <b>end</b> can also be used to end any block.</p>
a26fbde7ee28 documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 1090
diff changeset
133
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
134 <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
135
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
136 <h4 heading><a name="control" href="#control">Control Structures</a></h4>
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>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
139
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
140 <p>Luan does not have a <b>goto</b> statement.</p>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
141
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
142 <h4 heading><a name="for" href="#for">For Statement</a></h4>
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 <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
145
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
146 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
147 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
148 </pre>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
149
468
9b51e2413cab documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 465
diff changeset
150 <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
151
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
152 <pre>
390
Franklin Schmidt <fschmidt@gmail.com>
parents: 389
diff changeset
153 for var_1, &middot;&middot;&middot;, var_n in exp do block end
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
154 </pre>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
155
389
497d4ef0a89f documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 387
diff changeset
156 <p>is equivalent to the code:</p>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
157
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
158 <pre>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
159 do
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
160 local f = exp
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
161 while true do
390
Franklin Schmidt <fschmidt@gmail.com>
parents: 389
diff changeset
162 local var_1, &middot;&middot;&middot;, var_n = f()
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
163 if var_1 == nil then break end
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
164 block
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
165 end
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
166 end
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
167 </pre>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
168
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
169 <h4 heading><a name="logical" href="#logical">Logical Statements</a></h4>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
170
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
171 <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
172
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 x==5 or error "x should be 5"
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
175 </pre>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
176
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
177 <h4 heading><a name="template_stmt" href="#template_stmt">Template Statements</a></h4>
367
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
178
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
179 <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
180
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
181
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
182 <h3 heading><a name="expr" href="#expr">Expressions</a></h3>
367
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
183
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
184 <h4 heading><a name="conversions" href="#conversions">Coercions and Conversions</a></h4>
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
185
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
186 <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
187
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
188 <h4 heading><a name="bit" href="#bit">Bitwise Operators</a></h4>
367
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
189
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
190 <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
191
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
192 <h4 heading><a name="logical_ops" href="#logical_ops">Logical Operators</a></h4>
367
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
193
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
194 <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
195
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
196 <h4 heading><a name="concatenation" href="#concatenation">Concatenation</a></h4>
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
197
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
198 <p>Unlike Lua, Luan converts all concatenation operands to strings.
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
199
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
200 <h4 heading><a name="constructors" href="#constructors">Table Constructors</a></h4>
686
33f1b4ad2c9d more documentation fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 685
diff changeset
201
33f1b4ad2c9d more documentation fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 685
diff changeset
202 <p>Unlike Lua, Luan considers an <b>end_of_line</b> to be a field separator in a table constructor.</p>
33f1b4ad2c9d more documentation fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 685
diff changeset
203
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
204 <h4 heading><a name="fn_calls" href="#fn_calls">Function Calls</a></h4>
367
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
205
1090
616761e0b9f6 update documentation for last change
Franklin Schmidt <fschmidt@gmail.com>
parents: 693
diff changeset
206 <p>Unlike Lua, Luan does not allow extra non-nil arguments to be passed to a function. In Luan, this causes an error. This change helps find coding mistakes that would be very hard to detect otherwise.</p>
616761e0b9f6 update documentation for last change
Franklin Schmidt <fschmidt@gmail.com>
parents: 693
diff changeset
207
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
208 <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
209
685
1e4b0bc0202d update documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 604
diff changeset
210 <p>Luan doesn't support <em>proper tail calls</em>. Because Java doesn't support this cleanly, this was left out.</p>
1e4b0bc0202d update documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 604
diff changeset
211
1327
b29eefad2111 website - improve docs
Franklin Schmidt <fschmidt@gmail.com>
parents: 1326
diff changeset
212 <h4 heading><a name="template_expr" href="#template_expr">Template Expressions</a></h4>
367
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
213
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
214 <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
215
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
216 </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
217 </html>