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<h3>Table of Contents</h3>
<ul class="link-list" role="directory">
<li><a href="#module-Racc-label-Command-line+Reference">Command-line Reference</a>
<li><a href="#module-Racc-label-Generating+Parser+Using+Racc">Generating Parser Using Racc</a>
<li><a href="#module-Racc-label-Writing+A+Racc+Grammar+File">Writing A Racc Grammar File</a>
<li><a href="#module-Racc-label-Parser">Parser</a>
<li><a href="#module-Racc-label-Debugging">Debugging</a>
<li><a href="#module-Racc-label-Racc+reported+syntax+error.">Racc reported syntax error.</a>
<li><a href="#module-Racc-label-Racc+reported+-22XXXX+conflicts-22.">Racc reported “XXXX conflicts”.</a>
<li><a href="#module-Racc-label-Generated+parsers+does+not+work+correctly">Generated parsers does not work correctly</a>
<li><a href="#module-Racc-label-Re-distributing+Racc+runtime">Re-distributing Racc runtime</a>
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<h1 id="module-Racc" class="module">
module Racc
</h1>
<section class="description">
<p>$Id: 74ff4369ce53c7f45cfc2644ce907785104ebf6e $</p>
<p><a href="Racc.html#Copyright"><code>Copyright</code></a> © 1999-2006 Minero Aoki</p>
<p>This program is free software. You can distribute/modify this program under the terms of the GNU LGPL, Lesser General Public License version 2.1. For details of LGPL, see the file “COPYING”.</p>
<p>$Id: ebb9798ad0b211e031670a12a1ab154678c1c8f3 $</p>
<p><a href="Racc.html#Copyright"><code>Copyright</code></a> © 1999-2006 Minero Aoki</p>
<p>This program is free software. You can distribute/modify this program under the same terms of ruby. see the file “COPYING”.</p>
<p>$Id: 8ab2cb5341529fe5e35956bb1a1f42ec9b9c6f5a $</p>
<p><a href="Racc.html#Copyright"><code>Copyright</code></a> © 1999-2006 Minero Aoki</p>
<p>This program is free software. You can distribute/modify this program under the same terms of ruby. see the file “COPYING”.</p>
<p>$Id: 31aa4331c08dfd4609c06eb5f94b7ef38dc708e1 $</p>
<p><a href="Racc.html#Copyright"><code>Copyright</code></a> © 1999-2006 Minero Aoki</p>
<p>This program is free software. You can distribute/modify this program under the terms of the GNU LGPL, Lesser General Public License version 2.1. For details of the GNU LGPL, see the file “COPYING”.</p>
<p>$Id: 5e9d0a01b5d56fd9cdc3d5cb078b1a3e1bbaf779 $</p>
<p><a href="Racc.html#Copyright"><code>Copyright</code></a> © 1999-2006 Minero Aoki</p>
<p>This program is free software. You can distribute/modify this program under the terms of the GNU LGPL, Lesser General Public License version 2.1. For details of the GNU LGPL, see the file “COPYING”.</p>
<p><a href="Racc.html"><code>Racc</code></a> is a LALR(1) parser generator. It is written in Ruby itself, and generates Ruby programs.</p>
<h2 id="module-Racc-label-Command-line+Reference">Command-line Reference<span><a href="#module-Racc-label-Command-line+Reference">¶</a> <a href="#top">↑</a></span></h2>
<pre>racc [-o<var>filename</var>] [--output-file=<var>filename</var>]
[-e<var>rubypath</var>] [--embedded=<var>rubypath</var>]
[-v] [--verbose]
[-O<var>filename</var>] [--log-file=<var>filename</var>]
[-g] [--debug]
[-E] [--embedded]
[-l] [--no-line-convert]
[-c] [--line-convert-all]
[-a] [--no-omit-actions]
[-C] [--check-only]
[-S] [--output-status]
[--version] [--copyright] [--help] <var>grammarfile</var></pre>
<dl class="rdoc-list label-list"><dt><code>filename</code>
<dd>
<p><a href="Racc.html"><code>Racc</code></a> grammar file. Any extension is permitted.</p>
</dd><dt>-o+outfile+, –output-file=<code>outfile</code>
<dd>
<p>A filename for output. default is <<code>filename</code>>.tab.rb</p>
</dd><dt>-O+filename+, –log-file=<code>filename</code>
<dd>
<p>Place logging output in file <code>filename</code>. Default log file name is <<code>filename</code>>.output.</p>
</dd><dt>-e+rubypath+, –executable=<code>rubypath</code>
<dd>
<p>output executable file(mode 755). where <code>path</code> is the Ruby interpreter.</p>
</dd><dt>-v, –verbose
<dd>
<p>verbose mode. create <code>filename</code>.output file, like yacc's y.output file.</p>
</dd><dt>-g, –debug
<dd>
<p>add debug code to parser class. To display debuggin information, use this '-g' option and set @yydebug true in parser class.</p>
</dd><dt>-E, –embedded
<dd>
<p>Output parser which doesn't need runtime files (racc/parser.rb).</p>
</dd><dt>-C, –check-only
<dd>
<p>Check syntax of racc grammar file and quit.</p>
</dd><dt>-S, –output-status
<dd>
<p>Print messages time to time while compiling.</p>
</dd><dt>-l, –no-line-convert
<dd>
<p>turns off line number converting.</p>
</dd><dt>-c, –line-convert-all
<dd>
<p>Convert line number of actions, inner, header and footer.</p>
</dd><dt>-a, –no-omit-actions
<dd>
<p>Call all actions, even if an action is empty.</p>
</dd><dt>–version
<dd>
<p>print <a href="Racc.html"><code>Racc</code></a> version and quit.</p>
</dd><dt>–copyright
<dd>
<p>Print copyright and quit.</p>
</dd><dt>–help
<dd>
<p>Print usage and quit.</p>
</dd></dl>
<h2 id="module-Racc-label-Generating+Parser+Using+Racc">Generating <a href="Racc/Parser.html"><code>Parser</code></a> Using <a href="Racc.html"><code>Racc</code></a><span><a href="#module-Racc-label-Generating+Parser+Using+Racc">¶</a> <a href="#top">↑</a></span></h2>
<p>To compile <a href="Racc.html"><code>Racc</code></a> grammar file, simply type:</p>
<pre>$ racc parse.y</pre>
<p>This creates Ruby script file “parse.tab.y”. The -o option can change the output filename.</p>
<h2 id="module-Racc-label-Writing+A+Racc+Grammar+File">Writing A <a href="Racc.html"><code>Racc</code></a> <a href="Racc/Grammar.html"><code>Grammar</code></a> <a href="File.html"><code>File</code></a><span><a href="#module-Racc-label-Writing+A+Racc+Grammar+File">¶</a> <a href="#top">↑</a></span></h2>
<p>If you want your own parser, you have to write a grammar file. A grammar file contains the name of your parser class, grammar for the parser, user code, and anything else. When writing a grammar file, yacc's knowledge is helpful. If you have not used yacc before, <a href="Racc.html"><code>Racc</code></a> is not too difficult.</p>
<p>Here's an example <a href="Racc.html"><code>Racc</code></a> grammar file.</p>
<pre>class Calcparser
rule
target: exp { print val[0] }
exp: exp '+' exp
| exp '*' exp
| '(' exp ')'
| NUMBER
end</pre>
<p><a href="Racc.html"><code>Racc</code></a> grammar files resemble yacc files. But (of course), this is Ruby code. yacc's $$ is the 'result', $0, $1… is an array called 'val', and $-1, $-2… is an array called '_values'.</p>
<p>See the <a href="lib/racc/rdoc/grammar_en_rdoc.html">Grammar File Reference</a> for more information on grammar files.</p>
<h2 id="module-Racc-label-Parser"><a href="Racc/Parser.html"><code>Parser</code></a><span><a href="#module-Racc-label-Parser">¶</a> <a href="#top">↑</a></span></h2>
<p>Then you must prepare the parse entry method. There are two types of parse methods in <a href="Racc.html"><code>Racc</code></a>, Racc::Parser#do_parse and Racc::Parser#yyparse</p>
<p>Racc::Parser#do_parse is simple.</p>
<p>It's yyparse() of yacc, and <a href="Racc/Parser.html#method-i-next_token"><code>Racc::Parser#next_token</code></a> is yylex(). This method must returns an array like [TOKENSYMBOL, ITS_VALUE]. EOF is [false, false]. (TOKENSYMBOL is a Ruby symbol (taken from <a href="String.html#method-i-intern"><code>String#intern</code></a>) by default. If you want to change this, see the grammar reference.</p>
<p>Racc::Parser#yyparse is little complicated, but useful. It does not use <a href="Racc/Parser.html#method-i-next_token"><code>Racc::Parser#next_token</code></a>, instead it gets tokens from any iterator.</p>
<p>For example, <code>yyparse(obj, :scan)</code> causes calling +obj#scan+, and you can return tokens by yielding them from +obj#scan+.</p>
<h2 id="module-Racc-label-Debugging">Debugging<span><a href="#module-Racc-label-Debugging">¶</a> <a href="#top">↑</a></span></h2>
<p>When debugging, “-v” or/and the “-g” option is helpful.</p>
<p>“-v” creates verbose log file (.output). “-g” creates a “Verbose Parser”. Verbose <a href="Racc/Parser.html"><code>Parser</code></a> prints the internal status when parsing. But it's <em>not</em> automatic. You must use -g option and set +@yydebug+ to <code>true</code> in order to get output. -g option only creates the verbose parser.</p>
<h3 id="module-Racc-label-Racc+reported+syntax+error."><a href="Racc.html"><code>Racc</code></a> reported syntax error.<span><a href="#module-Racc-label-Racc+reported+syntax+error.">¶</a> <a href="#top">↑</a></span></h3>
<p>Isn't there too many “end”? grammar of racc file is changed in v0.10.</p>
<p><a href="Racc.html"><code>Racc</code></a> does not use '%' mark, while yacc uses huge number of '%' marks..</p>
<h3 id="module-Racc-label-Racc+reported+-22XXXX+conflicts-22."><a href="Racc.html"><code>Racc</code></a> reported “XXXX conflicts”.<span><a href="#module-Racc-label-Racc+reported+-22XXXX+conflicts-22.">¶</a> <a href="#top">↑</a></span></h3>
<p>Try “racc -v xxxx.y”. It causes producing racc's internal log file, xxxx.output.</p>
<h3 id="module-Racc-label-Generated+parsers+does+not+work+correctly">Generated parsers does not work correctly<span><a href="#module-Racc-label-Generated+parsers+does+not+work+correctly">¶</a> <a href="#top">↑</a></span></h3>
<p>Try “racc -g xxxx.y”. This command let racc generate “debugging parser”. Then set @yydebug=true in your parser. It produces a working log of your parser.</p>
<h2 id="module-Racc-label-Re-distributing+Racc+runtime">Re-distributing <a href="Racc.html"><code>Racc</code></a> runtime<span><a href="#module-Racc-label-Re-distributing+Racc+runtime">¶</a> <a href="#top">↑</a></span></h2>
<p>A parser, which is created by <a href="Racc.html"><code>Racc</code></a>, requires the <a href="Racc.html"><code>Racc</code></a> runtime module; racc/parser.rb.</p>
<p>Ruby 1.8.x comes with <a href="Racc.html"><code>Racc</code></a> runtime module, you need NOT distribute <a href="Racc.html"><code>Racc</code></a> runtime files.</p>
<p>If you want to include the <a href="Racc.html"><code>Racc</code></a> runtime module with your parser. This can be done by using '-E' option:</p>
<pre>$ racc -E -omyparser.rb myparser.y</pre>
<p>This command creates myparser.rb which `includes' <a href="Racc.html"><code>Racc</code></a> runtime. Only you must do is to distribute your parser file (myparser.rb).</p>
<p>Note: parser.rb is ruby license, but your parser is not. Your own parser is completely yours.</p>
<p>$Id: 3b2d89d9ada2f5fcb043837dcc5c9631856d5b70 $</p>
<p><a href="Racc.html#Copyright"><code>Copyright</code></a> © 1999-2006 Minero Aoki</p>
<p>This program is free software. You can distribute/modify this program under the terms of the GNU LGPL, Lesser General Public License version 2.1. For details of LGPL, see the file “COPYING”.</p>
</section>
<section id="5Buntitled-5D" class="documentation-section">
<section class="constants-list">
<header>
<h3>Constants</h3>
</header>
<dl>
<dt id="Copyright">Copyright
<dd>
<dt id="GrammarFileParser">GrammarFileParser
<dd>
<dt id="PARSER_TEXT">PARSER_TEXT
<dd>
<dt id="StateTransitionTable">StateTransitionTable
<dd>
<dt id="VERSION">VERSION
<dd>
<dt id="Version">Version
<dd>
</dl>
</section>
</section>
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