annotate website/src/diff.html.luan @ 735:2486fa6490c6

add Io.my_ips()
author Franklin Schmidt <fschmidt@gmail.com>
date Tue, 14 Jun 2016 18:24:28 -0600
parents ca169567ce07
children 616761e0b9f6
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
693
ca169567ce07 module URIs must now include ".luan"
Franklin Schmidt <fschmidt@gmail.com>
parents: 686
diff changeset
1 local Io = require "luan:Io.luan"
ca169567ce07 module URIs must now include ".luan"
Franklin Schmidt <fschmidt@gmail.com>
parents: 686
diff changeset
2 local Http = require "luan:http/Http.luan"
ca169567ce07 module URIs must now include ".luan"
Franklin Schmidt <fschmidt@gmail.com>
parents: 686
diff changeset
3 local Shared = require "site:/Shared.luan"
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>
686
33f1b4ad2c9d more documentation fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 685
diff changeset
62 <li><a href="#constructors">Table Constructors</a></li>
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
63 <li><a href="#fn_calls">Function Calls</a></li>
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
64 <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
65 </ul>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
66 </li>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
67 </ul>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
68 </div>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
69
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
70 <hr/>
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
71
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
72 <h2 heading><a name="intro">Introduction</a></h2>
372
f08cefa4594c start editing manual
Franklin Schmidt <fschmidt@gmail.com>
parents: 370
diff changeset
73
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
74 <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
75
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
76 <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
77
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
78 <h2 heading><a name="basic">Basic Concepts</a></h2>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
79
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
80 <h3 heading><a name="types">Values and Types</a></h3>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
81
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
82 <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
83
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
84 <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
85
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
86 <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
87
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
88 <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
89
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
90 <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
91
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
92 <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
93
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
94 <h3 heading><a name="env">Environments</a></h3>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
95
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
96 <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
97
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
98 <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
99
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
100 <h3 heading><a name="error">Error Handling</a></h3>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
101
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
102 <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
103
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
104 <h3 heading><a name="meta">Metatables and Metamethods</a></h3>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
105
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
106 <p>Luan only has metatable for tables, not for other types.</p>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
107
685
1e4b0bc0202d update documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 604
diff changeset
108 <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
109
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
110 <h3 heading><a name="gc">Garbage Collection</a></h3>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
111
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
112 <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
113
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
114 <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
115
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
116 <h3 heading><a name="coroutines">Coroutines</a></h3>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
117
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
118 <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
119
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
120 <h2 heading><a name="lang">The Language</a></h2>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
121
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
122 <h3 heading><a name="lex">Lexical Conventions</a></h3>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
123
685
1e4b0bc0202d update documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 604
diff changeset
124 <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
125
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
126 <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
127
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
128 <h3 heading><a name="vars">Variables</a></h3>
512
d96944467ffc update documentation for luan changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 505
diff changeset
129
d96944467ffc update documentation for luan changes
Franklin Schmidt <fschmidt@gmail.com>
parents: 505
diff changeset
130 <p>
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
131 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
132
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
133 <h3 heading><a name="stmt">Statements</a></h3>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
134
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
135 <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
136
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
137 <h4 heading><a name="control">Control Structures</a></h4>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
138
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
139 <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
140
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
141 <p>Luan does not have a <b>goto</b> statement.</p>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
142
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
143 <h4 heading><a name="for">For Statement</a></h4>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
144
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
145 <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
146
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
147 <pre>
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
148 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
149 </pre>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
150
468
9b51e2413cab documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 465
diff changeset
151 <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
152
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
153 <pre>
390
Franklin Schmidt <fschmidt@gmail.com>
parents: 389
diff changeset
154 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
155 </pre>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
156
389
497d4ef0a89f documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 387
diff changeset
157 <p>is equivalent to the code:</p>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
158
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
159 <pre>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
160 do
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
161 local f = exp
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
162 while true do
390
Franklin Schmidt <fschmidt@gmail.com>
parents: 389
diff changeset
163 local var_1, &middot;&middot;&middot;, var_n = f()
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
164 if var_1 == nil then break end
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
165 block
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
166 end
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
167 end
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
168 </pre>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
169
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
170 <h4 heading><a name="logical">Logical Statements</a></h4>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
171
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
172 <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
173
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
174 <pre>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
175 x==5 or error "x should be 5"
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
176 </pre>
353
38c19ecc384d start documentation
Franklin Schmidt <fschmidt@gmail.com>
parents:
diff changeset
177
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
178 <h4 heading><a name="template_stmt">Template Statements</a></h4>
367
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
179
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
180 <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
181
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
182
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
183 <h3 heading><a name="expr">Expressions</a></h3>
367
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
184
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
185 <h4 heading><a name="conversions">Coercions and Conversions</a></h4>
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
186
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
187 <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
188
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
189 <h4 heading><a name="bit">Bitwise Operators</a></h4>
367
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
190
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
191 <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
192
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
193 <h4 heading><a name="logical_ops">Logical Operators</a></h4>
367
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
194
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
195 <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
196
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
197 <h4 heading><a name="concatenation">Concatenation</a></h4>
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
198
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
199 <p>Unlike Lua, Luan converts all concatenation operands to strings.
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
200
686
33f1b4ad2c9d more documentation fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 685
diff changeset
201 <h4 heading><a name="constructors">Table Constructors</a></h4>
33f1b4ad2c9d more documentation fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 685
diff changeset
202
33f1b4ad2c9d more documentation fixes
Franklin Schmidt <fschmidt@gmail.com>
parents: 685
diff changeset
203 <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
204
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
205 <h4 heading><a name="fn_calls">Function Calls</a></h4>
367
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
206
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
207 <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
208
685
1e4b0bc0202d update documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 604
diff changeset
209 <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
210
562
7cc9d4a53d3b remove SimplyHTML from documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 513
diff changeset
211 <h4 heading><a name="template_expr">Template Expressions</a></h4>
367
c207be7cf45d more documentation
Franklin Schmidt <fschmidt@gmail.com>
parents: 354
diff changeset
212
465
47c7de1f2322 documentation work
Franklin Schmidt <fschmidt@gmail.com>
parents: 464
diff changeset
213 <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
214
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
215 </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
216 </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
217 <%
386
db23f654f87d make all of website use luan
Franklin Schmidt <fschmidt@gmail.com>
parents: 372
diff changeset
218 end