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Handle first h1 tag differently. git-svn-id: https://luan-java.googlecode.com/svn/trunk@243 21e917c8-12df-6dd8-5cb6-c86387c605b9
author hugo.tech@gmail.com <hugo.tech@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
date Tue, 07 Oct 2014 01:43:07 +0000
parents 852840d64a7f
children c912f6de2053
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241:852840d64a7f 242:b5a926c481a5
9 </head> 9 </head>
10 10
11 <body> 11 <body>
12 12
13 <hr> 13 <hr>
14 <h1> 14 <h1 class="main">
15 Luan Reference Manual 15 Luan Reference Manual
16 </h1> 16 </h1>
17 17
18 <P> 18 <P>
19 The reference manual is the official definition of the Luan language. 19 The reference manual is the official definition of the Luan language.
174 For a discussion of the decisions behind the design of Lua, 174 For a discussion of the decisions behind the design of Lua,
175 see the technical papers available at Lua's web site. 175 see the technical papers available at Lua's web site.
176 For a detailed introduction to programming in Lua, 176 For a detailed introduction to programming in Lua,
177 see Roberto's book, <em>Programming in Lua</em>. 177 see Roberto's book, <em>Programming in Lua</em>.
178 178
179
180 <h1>2 &ndash; <a name="2">Basic Concepts</a></h1> 179 <h1>2 &ndash; <a name="2">Basic Concepts</a></h1>
181 180
182 <p> 181 <p>
183 This section describes the basic concepts of the language. 182 This section describes the basic concepts of the language.
184 183
1174 <pre> 1173 <pre>
1175 function foo (a) 1174 function foo (a)
1176 print("foo", a) 1175 print("foo", a)
1177 return coroutine.yield(2*a) 1176 return coroutine.yield(2*a)
1178 end 1177 end
1179 1178
1180 co = coroutine.create(function (a,b) 1179 co = coroutine.create(function (a,b)
1181 print("co-body", a, b) 1180 print("co-body", a, b)
1182 local r = foo(a+1) 1181 local r = foo(a+1)
1183 print("co-body", r) 1182 print("co-body", r)
1184 local r, s = coroutine.yield(a+b, a-b) 1183 local r, s = coroutine.yield(a+b, a-b)
1185 print("co-body", r, s) 1184 print("co-body", r, s)
1186 return b, "end" 1185 return b, "end"
1187 end) 1186 end)
1188 1187
1189 print("main", coroutine.resume(co, 1, 10)) 1188 print("main", coroutine.resume(co, 1, 10))
1190 print("main", coroutine.resume(co, "r")) 1189 print("main", coroutine.resume(co, "r"))
1191 print("main", coroutine.resume(co, "x", "y")) 1190 print("main", coroutine.resume(co, "x", "y"))
1192 print("main", coroutine.resume(co, "x", "y")) 1191 print("main", coroutine.resume(co, "x", "y"))
1193 </pre><p> 1192 </pre><p>
1511 </pre><p> 1510 </pre><p>
1512 The grammar could see it in two ways: 1511 The grammar could see it in two ways:
1513 1512
1514 <pre> 1513 <pre>
1515 a = b + c(print or io.write)('done') 1514 a = b + c(print or io.write)('done')
1516 1515
1517 a = b + c; (print or io.write)('done') 1516 a = b + c; (print or io.write)('done')
1518 </pre><p> 1517 </pre><p>
1519 The current parser always sees such constructions 1518 The current parser always sees such constructions
1520 in the first way, 1519 in the first way,
1521 interpreting the open parenthesis 1520 interpreting the open parenthesis
1991 g(x, f()) -- g gets x plus all results from f() 1990 g(x, f()) -- g gets x plus all results from f()
1992 a,b,c = f(), x -- f() is adjusted to 1 result (c gets nil) 1991 a,b,c = f(), x -- f() is adjusted to 1 result (c gets nil)
1993 a,b = ... -- a gets the first vararg parameter, b gets 1992 a,b = ... -- a gets the first vararg parameter, b gets
1994 -- the second (both a and b can get nil if there 1993 -- the second (both a and b can get nil if there
1995 -- is no corresponding vararg parameter) 1994 -- is no corresponding vararg parameter)
1996 1995
1997 a,b,c = x, f() -- f() is adjusted to 2 results 1996 a,b,c = x, f() -- f() is adjusted to 2 results
1998 a,b,c = f() -- f() is adjusted to 3 results 1997 a,b,c = f() -- f() is adjusted to 3 results
1999 return f() -- returns all results from f() 1998 return f() -- returns all results from f()
2000 return ... -- returns all received vararg parameters 1999 return ... -- returns all received vararg parameters
2001 return x,y,f() -- returns x, y, and all results from f() 2000 return x,y,f() -- returns x, y, and all results from f()
2462 Then, we have the following mapping from arguments to parameters and 2461 Then, we have the following mapping from arguments to parameters and
2463 to the vararg expression: 2462 to the vararg expression:
2464 2463
2465 <pre> 2464 <pre>
2466 CALL PARAMETERS 2465 CALL PARAMETERS
2467 2466
2468 f(3) a=3, b=nil 2467 f(3) a=3, b=nil
2469 f(3, 4) a=3, b=4 2468 f(3, 4) a=3, b=4
2470 f(3, 4, 5) a=3, b=4 2469 f(3, 4, 5) a=3, b=4
2471 f(r(), 10) a=1, b=10 2470 f(r(), 10) a=1, b=10
2472 f(r()) a=1, b=2 2471 f(r()) a=1, b=2
2473 2472
2474 g(3) a=3, b=nil, ... --&gt; (nothing) 2473 g(3) a=3, b=nil, ... --&gt; (nothing)
2475 g(3, 4) a=3, b=4, ... --&gt; (nothing) 2474 g(3, 4) a=3, b=4, ... --&gt; (nothing)
2476 g(3, 4, 5, 8) a=3, b=4, ... --&gt; 5 8 2475 g(3, 4, 5, 8) a=3, b=4, ... --&gt; 5 8
2477 g(5, r()) a=5, b=1, ... --&gt; 2 3 2476 g(5, r()) a=5, b=1, ... --&gt; 2 3
2478 </pre> 2477 </pre>
8128 Here are some examples: 8127 Here are some examples:
8129 8128
8130 <pre> 8129 <pre>
8131 x = string.gsub("hello world", "(%w+)", "%1 %1") 8130 x = string.gsub("hello world", "(%w+)", "%1 %1")
8132 --&gt; x="hello hello world world" 8131 --&gt; x="hello hello world world"
8133 8132
8134 x = string.gsub("hello world", "%w+", "%0 %0", 1) 8133 x = string.gsub("hello world", "%w+", "%0 %0", 1)
8135 --&gt; x="hello hello world" 8134 --&gt; x="hello hello world"
8136 8135
8137 x = string.gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1") 8136 x = string.gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1")
8138 --&gt; x="world hello Lua from" 8137 --&gt; x="world hello Lua from"
8139 8138
8140 x = string.gsub("home = $HOME, user = $USER", "%$(%w+)", os.getenv) 8139 x = string.gsub("home = $HOME, user = $USER", "%$(%w+)", os.getenv)
8141 --&gt; x="home = /home/roberto, user = roberto" 8140 --&gt; x="home = /home/roberto, user = roberto"
8142 8141
8143 x = string.gsub("4+5 = $return 4+5$", "%$(.-)%$", function (s) 8142 x = string.gsub("4+5 = $return 4+5$", "%$(.-)%$", function (s)
8144 return load(s)() 8143 return load(s)()
8145 end) 8144 end)
8146 --&gt; x="4+5 = 9" 8145 --&gt; x="4+5 = 9"
8147 8146
8148 local t = {name="lua", version="5.2"} 8147 local t = {name="lua", version="5.2"}
8149 x = string.gsub("$name-$version.tar.gz", "%$(%w+)", t) 8148 x = string.gsub("$name-$version.tar.gz", "%$(%w+)", t)
8150 --&gt; x="lua-5.2.tar.gz" 8149 --&gt; x="lua-5.2.tar.gz"
8151 </pre> 8150 </pre>
8152 8151
8815 8814
8816 8815
8817 <p> 8816 <p>
8818 When called without arguments, 8817 When called without arguments,
8819 returns a uniform pseudo-random real number 8818 returns a uniform pseudo-random real number
8820 in the range <em>[0,1)</em>. 8819 in the range <em>[0,1)</em>.
8821 When called with an integer number <code>m</code>, 8820 When called with an integer number <code>m</code>,
8822 <code>math.random</code> returns 8821 <code>math.random</code> returns
8823 a uniform pseudo-random integer in the range <em>[1, m]</em>. 8822 a uniform pseudo-random integer in the range <em>[1, m]</em>.
8824 When called with two integer numbers <code>m</code> and <code>n</code>, 8823 When called with two integer numbers <code>m</code> and <code>n</code>,
8825 <code>math.random</code> returns a uniform pseudo-random 8824 <code>math.random</code> returns a uniform pseudo-random
10169 when the standard input (<code>stdin</code>) is a terminal, 10168 when the standard input (<code>stdin</code>) is a terminal,
10170 and as <code>lua -</code> otherwise. 10169 and as <code>lua -</code> otherwise.
10171 10170
10172 10171
10173 <p> 10172 <p>
10174 When called without option <code>-E</code>, 10173 When called without option <code>-E</code>,
10175 the interpreter checks for an environment variable <a name="pdf-LUA_INIT_5_2"><code>LUA_INIT_5_2</code></a> 10174 the interpreter checks for an environment variable <a name="pdf-LUA_INIT_5_2"><code>LUA_INIT_5_2</code></a>
10176 (or <a name="pdf-LUA_INIT"><code>LUA_INIT</code></a> if it is not defined) 10175 (or <a name="pdf-LUA_INIT"><code>LUA_INIT</code></a> if it is not defined)
10177 before running any argument. 10176 before running any argument.
10178 If the variable content has the format <code>@<em>filename</em></code>, 10177 If the variable content has the format <code>@<em>filename</em></code>,
10179 then <code>lua</code> executes the file. 10178 then <code>lua</code> executes the file.
10515 10514
10516 chunk ::= block 10515 chunk ::= block
10517 10516
10518 block ::= {stat} [retstat] 10517 block ::= {stat} [retstat]
10519 10518
10520 stat ::= &lsquo;<b>;</b>&rsquo; | 10519 stat ::= &lsquo;<b>;</b>&rsquo; |
10521 varlist &lsquo;<b>=</b>&rsquo; explist | 10520 varlist &lsquo;<b>=</b>&rsquo; explist |
10522 functioncall | 10521 functioncall |
10523 label | 10522 label |
10524 <b>break</b> | 10523 <b>break</b> |
10525 <b>goto</b> Name | 10524 <b>goto</b> Name |
10526 <b>do</b> block <b>end</b> | 10525 <b>do</b> block <b>end</b> |
10527 <b>while</b> exp <b>do</b> block <b>end</b> | 10526 <b>while</b> exp <b>do</b> block <b>end</b> |
10528 <b>repeat</b> block <b>until</b> exp | 10527 <b>repeat</b> block <b>until</b> exp |
10529 <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] <b>end</b> | 10528 <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] <b>end</b> |
10530 <b>for</b> Name &lsquo;<b>=</b>&rsquo; exp &lsquo;<b>,</b>&rsquo; exp [&lsquo;<b>,</b>&rsquo; exp] <b>do</b> block <b>end</b> | 10529 <b>for</b> Name &lsquo;<b>=</b>&rsquo; exp &lsquo;<b>,</b>&rsquo; exp [&lsquo;<b>,</b>&rsquo; exp] <b>do</b> block <b>end</b> |
10531 <b>for</b> namelist <b>in</b> explist <b>do</b> block <b>end</b> | 10530 <b>for</b> namelist <b>in</b> explist <b>do</b> block <b>end</b> |
10532 <b>function</b> funcname funcbody | 10531 <b>function</b> funcname funcbody |
10533 <b>local</b> <b>function</b> Name funcbody | 10532 <b>local</b> <b>function</b> Name funcbody |
10534 <b>local</b> namelist [&lsquo;<b>=</b>&rsquo; explist] 10533 <b>local</b> namelist [&lsquo;<b>=</b>&rsquo; explist]
10535 10534
10536 retstat ::= <b>return</b> [explist] [&lsquo;<b>;</b>&rsquo;] 10535 retstat ::= <b>return</b> [explist] [&lsquo;<b>;</b>&rsquo;]
10537 10536
10538 label ::= &lsquo;<b>::</b>&rsquo; Name &lsquo;<b>::</b>&rsquo; 10537 label ::= &lsquo;<b>::</b>&rsquo; Name &lsquo;<b>::</b>&rsquo;
10539 10538
10540 funcname ::= Name {&lsquo;<b>.</b>&rsquo; Name} [&lsquo;<b>:</b>&rsquo; Name] 10539 funcname ::= Name {&lsquo;<b>.</b>&rsquo; Name} [&lsquo;<b>:</b>&rsquo; Name]
10541 10540
10542 varlist ::= var {&lsquo;<b>,</b>&rsquo; var} 10541 varlist ::= var {&lsquo;<b>,</b>&rsquo; var}
10543 10542
10544 var ::= Name | prefixexp &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo; | prefixexp &lsquo;<b>.</b>&rsquo; Name 10543 var ::= Name | prefixexp &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo; | prefixexp &lsquo;<b>.</b>&rsquo; Name
10545 10544
10546 namelist ::= Name {&lsquo;<b>,</b>&rsquo; Name} 10545 namelist ::= Name {&lsquo;<b>,</b>&rsquo; Name}
10547 10546
10548 explist ::= exp {&lsquo;<b>,</b>&rsquo; exp} 10547 explist ::= exp {&lsquo;<b>,</b>&rsquo; exp}
10549 10548
10550 exp ::= <b>nil</b> | <b>false</b> | <b>true</b> | Number | String | &lsquo;<b>...</b>&rsquo; | functiondef | 10549 exp ::= <b>nil</b> | <b>false</b> | <b>true</b> | Number | String | &lsquo;<b>...</b>&rsquo; | functiondef |
10551 prefixexp | tableconstructor | exp binop exp | unop exp 10550 prefixexp | tableconstructor | exp binop exp | unop exp
10552 10551
10553 prefixexp ::= var | functioncall | &lsquo;<b>(</b>&rsquo; exp &lsquo;<b>)</b>&rsquo; 10552 prefixexp ::= var | functioncall | &lsquo;<b>(</b>&rsquo; exp &lsquo;<b>)</b>&rsquo;
10554 10553
10555 functioncall ::= prefixexp args | prefixexp &lsquo;<b>:</b>&rsquo; Name args 10554 functioncall ::= prefixexp args | prefixexp &lsquo;<b>:</b>&rsquo; Name args
10556 10555
10557 args ::= &lsquo;<b>(</b>&rsquo; [explist] &lsquo;<b>)</b>&rsquo; | tableconstructor | String 10556 args ::= &lsquo;<b>(</b>&rsquo; [explist] &lsquo;<b>)</b>&rsquo; | tableconstructor | String
10558 10557
10559 functiondef ::= <b>function</b> funcbody 10558 functiondef ::= <b>function</b> funcbody
10560 10559
10561 funcbody ::= &lsquo;<b>(</b>&rsquo; [parlist] &lsquo;<b>)</b>&rsquo; block <b>end</b> 10560 funcbody ::= &lsquo;<b>(</b>&rsquo; [parlist] &lsquo;<b>)</b>&rsquo; block <b>end</b>
10562 10561
10568 10567
10569 field ::= &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo; &lsquo;<b>=</b>&rsquo; exp | Name &lsquo;<b>=</b>&rsquo; exp | exp 10568 field ::= &lsquo;<b>[</b>&rsquo; exp &lsquo;<b>]</b>&rsquo; &lsquo;<b>=</b>&rsquo; exp | Name &lsquo;<b>=</b>&rsquo; exp | exp
10570 10569
10571 fieldsep ::= &lsquo;<b>,</b>&rsquo; | &lsquo;<b>;</b>&rsquo; 10570 fieldsep ::= &lsquo;<b>,</b>&rsquo; | &lsquo;<b>;</b>&rsquo;
10572 10571
10573 binop ::= &lsquo;<b>+</b>&rsquo; | &lsquo;<b>-</b>&rsquo; | &lsquo;<b>*</b>&rsquo; | &lsquo;<b>/</b>&rsquo; | &lsquo;<b>^</b>&rsquo; | &lsquo;<b>%</b>&rsquo; | &lsquo;<b>..</b>&rsquo; | 10572 binop ::= &lsquo;<b>+</b>&rsquo; | &lsquo;<b>-</b>&rsquo; | &lsquo;<b>*</b>&rsquo; | &lsquo;<b>/</b>&rsquo; | &lsquo;<b>^</b>&rsquo; | &lsquo;<b>%</b>&rsquo; | &lsquo;<b>..</b>&rsquo; |
10574 &lsquo;<b>&lt;</b>&rsquo; | &lsquo;<b>&lt;=</b>&rsquo; | &lsquo;<b>&gt;</b>&rsquo; | &lsquo;<b>&gt;=</b>&rsquo; | &lsquo;<b>==</b>&rsquo; | &lsquo;<b>~=</b>&rsquo; | 10573 &lsquo;<b>&lt;</b>&rsquo; | &lsquo;<b>&lt;=</b>&rsquo; | &lsquo;<b>&gt;</b>&rsquo; | &lsquo;<b>&gt;=</b>&rsquo; | &lsquo;<b>==</b>&rsquo; | &lsquo;<b>~=</b>&rsquo; |
10575 <b>and</b> | <b>or</b> 10574 <b>and</b> | <b>or</b>
10576 10575
10577 unop ::= &lsquo;<b>-</b>&rsquo; | <b>not</b> | &lsquo;<b>#</b>&rsquo; 10576 unop ::= &lsquo;<b>-</b>&rsquo; | <b>not</b> | &lsquo;<b>#</b>&rsquo;
10578 10577
10579 </pre> 10578 </pre>