diff mayachemtools/docs/modules/html/code/YYLexer.html @ 0:73ae111cf86f draft

Uploaded
author deepakjadmin
date Wed, 20 Jan 2016 11:55:01 -0500
parents
children
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mayachemtools/docs/modules/html/code/YYLexer.html	Wed Jan 20 11:55:01 2016 -0500
@@ -0,0 +1,325 @@
+<html>
+<head>
+<title>MayaChemTools:Code:Parsers::YYLexer.pm</title>
+<meta http-equiv="content-type" content="text/html;charset=utf-8">
+<link rel="stylesheet" type="text/css" href="../../../css/MayaChemToolsCode.css">
+</head>
+<body leftmargin="20" rightmargin="20" topmargin="10" bottommargin="10">
+<br/>
+<center>
+<a href="http://www.mayachemtools.org" title="MayaChemTools Home"><img src="../../../images/MayaChemToolsLogo.gif" border="0" alt="MayaChemTools"></a>
+</center>
+<br/>
+<pre>
+<a name="package-Parsers::YYLexer-"></a>   1 <span class="k">package </span><span class="i">Parsers::YYLexer</span><span class="sc">;</span>
+   2 <span class="c">#</span>
+   3 <span class="c"># $RCSfile: YYLexer.pm,v $</span>
+   4 <span class="c"># $Date: 2015/02/28 20:50:55 $</span>
+   5 <span class="c"># $Revision: 1.10 $</span>
+   6 <span class="c">#</span>
+   7 <span class="c"># Author: Manish Sud &lt;msud@san.rr.com&gt;</span>
+   8 <span class="c">#</span>
+   9 <span class="c"># Copyright (C) 2015 Manish Sud. All rights reserved.</span>
+  10 <span class="c">#</span>
+  11 <span class="c"># This file is part of MayaChemTools.</span>
+  12 <span class="c">#</span>
+  13 <span class="c"># MayaChemTools is free software; you can redistribute it and/or modify it under</span>
+  14 <span class="c"># the terms of the GNU Lesser General Public License as published by the Free</span>
+  15 <span class="c"># Software Foundation; either version 3 of the License, or (at your option) any</span>
+  16 <span class="c"># later version.</span>
+  17 <span class="c">#</span>
+  18 <span class="c"># MayaChemTools is distributed in the hope that it will be useful, but without</span>
+  19 <span class="c"># any warranty; without even the implied warranty of merchantability of fitness</span>
+  20 <span class="c"># for a particular purpose.  See the GNU Lesser General Public License for more</span>
+  21 <span class="c"># details.</span>
+  22 <span class="c">#</span>
+  23 <span class="c"># You should have received a copy of the GNU Lesser General Public License</span>
+  24 <span class="c"># along with MayaChemTools; if not, see &lt;http://www.gnu.org/licenses/&gt; or</span>
+  25 <span class="c"># write to the Free Software Foundation Inc., 59 Temple Place, Suite 330,</span>
+  26 <span class="c"># Boston, MA, 02111-1307, USA.</span>
+  27 <span class="c">#</span>
+  28 
+  29 <span class="k">use</span> <span class="w">strict</span><span class="sc">;</span>
+  30 <span class="k">use</span> <span class="w">Carp</span><span class="sc">;</span>
+  31 <span class="k">use</span> <span class="w">Exporter</span><span class="sc">;</span>
+  32 <span class="k">use</span> <span class="w">Scalar::Util</span> <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
+  33 <span class="k">use</span> <span class="w">Parsers::Lexer</span><span class="sc">;</span>
+  34 
+  35 <span class="k">use</span> <span class="w">vars</span> <span class="q">qw(@ISA @EXPORT @EXPORT_OK %EXPORT_TAGS)</span><span class="sc">;</span>
+  36 
+  37 <span class="i">@ISA</span> = <span class="q">qw(Parsers::Lexer Exporter)</span><span class="sc">;</span>
+  38 <span class="i">@EXPORT</span> = <span class="q">qw()</span><span class="sc">;</span>
+  39 <span class="i">@EXPORT_OK</span> = <span class="q">qw()</span><span class="sc">;</span>
+  40 
+  41 <span class="i">%EXPORT_TAGS</span> = <span class="s">(</span><span class="w">all</span>  <span class="cm">=&gt;</span> <span class="s">[</span><span class="i">@EXPORT</span><span class="cm">,</span> <span class="i">@EXPORT_OK</span><span class="s">]</span><span class="s">)</span><span class="sc">;</span>
+  42 
+  43 <span class="c"># Setup class variables...</span>
+  44 <span class="k">my</span><span class="s">(</span><span class="i">$ClassName</span><span class="s">)</span><span class="sc">;</span>
+  45 <span class="i">_InitializeClass</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
+  46 
+  47 <span class="c"># Overload Perl functions...</span>
+  48 <span class="k">use</span> <span class="w">overload</span> <span class="q">&#39;&quot;&quot;&#39;</span> <span class="cm">=&gt;</span> <span class="q">&#39;StringifyYYLexer&#39;</span><span class="sc">;</span>
+  49 
+  50 <span class="c"># Class constructor...</span>
+<a name="new-"></a>  51 <span class="k">sub </span><span class="m">new</span> <span class="s">{</span>
+  52   <span class="k">my</span><span class="s">(</span><span class="i">$Class</span><span class="cm">,</span> <span class="i">$Input</span><span class="cm">,</span>  <span class="i">@TokensSpec</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
+  53 
+  54   <span class="c"># Initialize object...</span>
+  55   <span class="k">my</span> <span class="i">$This</span> = <span class="i">$Class</span><span class="i">-&gt;SUPER::new</span><span class="s">(</span><span class="i">$Input</span><span class="cm">,</span>  <span class="i">@TokensSpec</span><span class="s">)</span><span class="sc">;</span>
+  56   <span class="k">bless</span> <span class="i">$This</span><span class="cm">,</span> <span class="k">ref</span><span class="s">(</span><span class="i">$Class</span><span class="s">)</span> || <span class="i">$Class</span><span class="sc">;</span>
+  57   <span class="i">$This</span><span class="i">-&gt;_InitializeYYLexer</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
+  58 
+  59   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
+  60 <span class="s">}</span>
+  61 
+  62 <span class="c"># Initialize object data...</span>
+  63 <span class="c">#</span>
+<a name="_InitializeYYLexer-"></a>  64 <span class="k">sub </span><span class="m">_InitializeYYLexer</span> <span class="s">{</span>
+  65   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
+  66 
+  67   <span class="c"># File generated containing mapping of token labels to token numbers by</span>
+  68   <span class="c"># running command byacc with -d option on a parser definition file.</span>
+  69   <span class="c">#</span>
+  70   <span class="c"># For example, &quot;byacc -l -P -d -b Parser Parser.yy&quot; would generate file</span>
+  71   <span class="c"># Parser.tab.ph, which might contain the following tokem name and values</span>
+  72   <span class="c"># for a parser for a simple calculator:</span>
+  73   <span class="c">#</span>
+  74   <span class="c">#  $NUMBER=257;</span>
+  75   <span class="c">#  $LETTER=258;</span>
+  76   <span class="c">#</span>
+  77   <span class="c">#</span>
+  78   <span class="i">$This</span>-&gt;{<span class="w">YYTabFile</span>} = <span class="k">undef</span><span class="sc">;</span>
+  79   <span class="i">$This</span>-&gt;{<span class="w">YYTabFilePath</span>} = <span class="k">undef</span><span class="sc">;</span>
+  80 
+  81   <span class="c"># Mapping of token lables to token numbers...</span>
+  82   <span class="i">%</span>{<span class="i">$This</span>-&gt;{<span class="w">YYTabDataMap</span>}} = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
+  83 
+  84   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
+  85 <span class="s">}</span>
+  86 
+  87 <span class="c"># Initialize class ...</span>
+<a name="_InitializeClass-"></a>  88 <span class="k">sub </span><span class="m">_InitializeClass</span> <span class="s">{</span>
+  89   <span class="c">#Class name...</span>
+  90 
+  91   <span class="i">$ClassName</span> = <span class="w">__PACKAGE__</span><span class="sc">;</span>
+  92 <span class="s">}</span>
+  93 
+  94 <span class="c"># Process tokens in YYTab file and load mapping of token labels to integers</span>
+  95 <span class="c"># for return during YYLex method invocation...</span>
+  96 <span class="c">#</span>
+  97 <span class="c"># Notes:</span>
+  98 <span class="c">#   . YYTabFile must be a complete path or available through @INC path in the</span>
+  99 <span class="c">#     same directory where this package is located.</span>
+ 100 <span class="c">#   . Name of YYTabFile might start with any valid sub directory name in @INC</span>
+ 101 <span class="c">#     For example, &quot;Parsers/&lt;YYTablFile&gt;&quot; implies the tab file in parsers sub directory</span>
+ 102 <span class="c">#     under MayaChemTools lib directory as it would be already in @INC path.</span>
+ 103 <span class="c">#   . YYTabFile must be explicitly set by the caller. The default YYTabFile name,</span>
+ 104 <span class="c">#     y.tab.ph, generated by byacc is not used implicitly to avoid confusion among</span>
+ 105 <span class="c">#     multiple distinct instances of YYLexer.</span>
+ 106 <span class="c">#   . YYTabFile is generated by byacc during its usage with -d options and contains</span>
+ 107 <span class="c">#     mapping of token codes to token names/labels. YYLexer used this file to map</span>
+ 108 <span class="c">#     token lables to token codes before retuning token code and value pair back</span>
+ 109 <span class="c">#     to yyparse function used by byacc.</span>
+ 110 <span class="c">#   . User defined token numbers start from 257</span>
+ 111 <span class="c">#</span>
+ 112 <span class="c">#     The format of YYTabFile generted by byacc during generation of parser code in</span>
+ 113 <span class="c">#     Perl code is:</span>
+ 114 <span class="c">#</span>
+ 115 <span class="c">#     ... ...</span>
+ 116 <span class="c">#     $NUMBER=257;</span>
+ 117 <span class="c">#     $ADDOP=258;</span>
+ 118 <span class="c">#     $SUBOP=259;</span>
+ 119 <span class="c">#     ... ..</span>
+ 120 <span class="c">#</span>
+<a name="SetupYYTabFile-"></a> 121 <span class="k">sub </span><span class="m">SetupYYTabFile</span> <span class="s">{</span>
+ 122   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="cm">,</span> <span class="i">$YYTabFile</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
+ 123   <span class="k">my</span><span class="s">(</span><span class="i">$YYTabFilePath</span><span class="cm">,</span> <span class="i">$Line</span><span class="cm">,</span> <span class="i">$TokenLabel</span><span class="cm">,</span> <span class="i">$TokenNumber</span><span class="s">)</span><span class="sc">;</span>
+ 124 
+ 125   <span class="i">$This</span>-&gt;{<span class="w">YYTabFile</span>} = <span class="k">undef</span><span class="sc">;</span>
+ 126   <span class="i">$This</span>-&gt;{<span class="w">YYTabFilePath</span>} = <span class="k">undef</span><span class="sc">;</span>
+ 127   <span class="i">%</span>{<span class="i">$This</span>-&gt;{<span class="w">YYTabDataMap</span>}} = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
+ 128 
+ 129   <span class="k">if</span> <span class="s">(</span>!<span class="k">defined</span> <span class="i">$YYTabFile</span><span class="s">)</span> <span class="s">{</span>
+ 130     <span class="w">croak</span> <span class="q">&quot;Error: ${ClassName}-&gt;SetupYYTabFile: YYTabFile must be specified...&quot;</span><span class="sc">;</span>
+ 131   <span class="s">}</span>
+ 132   <span class="i">$This</span>-&gt;{<span class="w">YYTabFile</span>} = <span class="i">$YYTabFile</span><span class="sc">;</span>
+ 133 
+ 134   <span class="k">if</span> <span class="s">(</span><span class="k">-e</span> <span class="i">$YYTabFile</span><span class="s">)</span> <span class="s">{</span>
+ 135     <span class="i">$YYTabFilePath</span> = <span class="i">$YYTabFile</span><span class="sc">;</span>
+ 136   <span class="s">}</span>
+ 137   <span class="k">else</span> <span class="s">{</span>
+ 138     <span class="s">(</span><span class="i">$YYTabFilePath</span><span class="s">)</span> = <span class="k">grep</span> <span class="s">{</span><span class="k">-f</span> <span class="q">&quot;$_/$YYTabFile&quot;</span><span class="s">}</span>  <span class="i">@INC</span><span class="sc">;</span>
+ 139     <span class="k">if</span> <span class="s">(</span>!<span class="i">$YYTabFilePath</span><span class="s">)</span> <span class="s">{</span>
+ 140       <span class="w">carp</span> <span class="q">&quot;Warning: ${ClassName}-&gt;SetupYYTabFile: YYTabFile, $YYTabFile,  can&#39;t be located in \@INC path: @INC...&quot;</span><span class="sc">;</span>
+ 141       <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
+ 142     <span class="s">}</span>
+ 143     <span class="i">$YYTabFilePath</span> = <span class="q">&quot;${YYTabFilePath}/$YYTabFile&quot;</span><span class="sc">;</span>
+ 144   <span class="s">}</span>
+ 145 
+ 146   <span class="i">$This</span>-&gt;{<span class="w">YYTabFilePath</span>} = <span class="i">$YYTabFilePath</span><span class="sc">;</span>
+ 147 
+ 148   <span class="k">open</span> <span class="w">YYTABFILE</span><span class="cm">,</span> <span class="q">&quot;$YYTabFilePath&quot;</span> <span class="k">or</span> <span class="k">die</span> <span class="q">&quot;Couldn&#39;t open $YYTabFilePath: $_\n&quot;</span><span class="sc">;</span>
+ 149   <span class="k">while</span> <span class="s">(</span><span class="i">$Line</span> = <span class="q">&lt;YYTABFILE&gt;</span><span class="s">)</span> <span class="s">{</span>
+ 150     <span class="s">(</span><span class="i">$TokenLabel</span><span class="cm">,</span> <span class="i">$TokenNumber</span><span class="s">)</span> = <span class="s">(</span><span class="i">$Line</span> =~ <span class="q">/^\$(.*?)=(.*?);$/</span><span class="s">)</span><span class="sc">;</span>
+ 151     <span class="k">if</span> <span class="s">(</span>!<span class="s">(</span><span class="k">defined</span><span class="s">(</span><span class="i">$TokenLabel</span><span class="s">)</span> &amp;&amp; <span class="k">defined</span><span class="s">(</span><span class="i">$TokenNumber</span><span class="s">)</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
+ 152       <span class="w">croak</span> <span class="q">&quot;Error: ${ClassName}-&gt;SetupYYTabFile: Couldn&#39;t extract token label and number from YYTabFile $YYTabFile at line: $Line...&quot;</span><span class="sc">;</span>
+ 153     <span class="s">}</span>
+ 154     <span class="k">if</span> <span class="s">(</span><span class="k">exists</span> <span class="i">$This</span>-&gt;{<span class="w">YYTabDataMap</span>}{<span class="i">$TokenLabel</span>}<span class="s">)</span> <span class="s">{</span>
+ 155       <span class="w">carp</span> <span class="q">&quot;Warning: ${ClassName}-&gt;SetupYYTabFile: Token lable, $TokenLabel, already defined in YYTabFile $YYTabFile...&quot;</span><span class="sc">;</span>
+ 156     <span class="s">}</span>
+ 157     <span class="i">$This</span>-&gt;{<span class="w">YYTabDataMap</span>}{<span class="i">$TokenLabel</span>} = <span class="i">$TokenNumber</span><span class="sc">;</span>
+ 158   <span class="s">}</span>
+ 159   <span class="k">close</span> <span class="w">YYTABFILE</span><span class="sc">;</span>
+ 160 
+ 161   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
+ 162 <span class="s">}</span>
+ 163 
+ 164 <span class="c"># Get next available token number and any matched text from input stream</span>
+ 165 <span class="c"># by either removing it from the input stream or simply peeking ahead.</span>
+ 166 <span class="c">#</span>
+ 167 <span class="c"># Supported mode values: Peek, Next. Default: Next</span>
+ 168 <span class="c">#</span>
+ 169 <span class="c"># Notes:</span>
+ 170 <span class="c">#   . Token label and value pairs returned by lexer, which can&#39;t be mapped to token</span>
+ 171 <span class="c">#     labels specified in YYTabFile are ignored.</span>
+ 172 <span class="c">#   . Token text of length 1 returned by lexer without a corresponding explicit token label,</span>
+ 173 <span class="c">#     which can&#39;t be mapped to a token number using Perl ord function, is ignored.</span>
+ 174 <span class="c">#</span>
+<a name="YYLex-"></a> 175 <span class="k">sub </span><span class="m">YYLex</span> <span class="s">{</span>
+ 176   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="cm">,</span> <span class="i">$Mode</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
+ 177   <span class="k">my</span><span class="s">(</span><span class="i">$LexerToken</span><span class="cm">,</span> <span class="i">$TokenLabel</span><span class="cm">,</span> <span class="i">$TokenNumber</span><span class="cm">,</span> <span class="i">$TokenText</span><span class="s">)</span><span class="sc">;</span>
+ 178 
+ 179   <span class="s">(</span><span class="i">$TokenLabel</span><span class="cm">,</span> <span class="i">$TokenNumber</span><span class="cm">,</span> <span class="i">$TokenText</span><span class="s">)</span> = <span class="s">(</span><span class="k">undef</span><span class="s">)</span> x <span class="n">3</span><span class="sc">;</span>
+ 180 
+ 181   <span class="j">TOKEN:</span> <span class="k">while</span> <span class="s">(</span><span class="k">defined</span><span class="s">(</span><span class="i">$LexerToken</span> = <span class="i">$This</span><span class="i">-&gt;Lex</span><span class="s">(</span><span class="i">$Mode</span><span class="s">)</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
+ 182     <span class="k">if</span> <span class="s">(</span><span class="k">ref</span> <span class="i">$LexerToken</span><span class="s">)</span> <span class="s">{</span>
+ 183       <span class="s">(</span><span class="i">$TokenLabel</span><span class="cm">,</span> <span class="i">$TokenText</span><span class="s">)</span> = <span class="i">@</span>{<span class="i">$LexerToken</span>}<span class="sc">;</span>
+ 184       <span class="k">if</span> <span class="s">(</span><span class="k">exists</span> <span class="i">$This</span>-&gt;{<span class="w">YYTabDataMap</span>}{<span class="i">$TokenLabel</span>}<span class="s">)</span> <span class="s">{</span>
+ 185         <span class="i">$TokenNumber</span> = <span class="i">$This</span>-&gt;{<span class="w">YYTabDataMap</span>}{<span class="i">$TokenLabel</span>}<span class="sc">;</span>
+ 186       <span class="s">}</span>
+ 187       <span class="k">elsif</span> <span class="s">(</span><span class="i">$TokenLabel</span> =~ <span class="q">/^EOI$/i</span><span class="s">)</span> <span class="s">{</span>
+ 188         <span class="i">$TokenNumber</span> = <span class="n">0</span><span class="sc">;</span>
+ 189       <span class="s">}</span>
+ 190     <span class="s">}</span>
+ 191     <span class="k">else</span> <span class="s">{</span>
+ 192       <span class="i">$TokenText</span> = <span class="i">$LexerToken</span><span class="sc">;</span>
+ 193     <span class="s">}</span>
+ 194 
+ 195     <span class="c"># Check for any literals (+, - , = etc.) to generte token numbers...</span>
+ 196     <span class="c">#</span>
+ 197     <span class="k">if</span> <span class="s">(</span>!<span class="k">defined</span> <span class="i">$TokenNumber</span><span class="s">)</span> <span class="s">{</span>
+ 198       <span class="k">if</span> <span class="s">(</span><span class="k">length</span><span class="s">(</span><span class="i">$TokenText</span><span class="s">)</span> == <span class="n">1</span> &amp;&amp; <span class="k">ord</span> <span class="i">$TokenText</span><span class="s">)</span> <span class="s">{</span>
+ 199         <span class="i">$TokenNumber</span> = <span class="k">ord</span> <span class="i">$TokenText</span><span class="sc">;</span>
+ 200       <span class="s">}</span>
+ 201     <span class="s">}</span>
+ 202 
+ 203     <span class="c"># Generate error message for no mapping to token numbers...</span>
+ 204     <span class="k">if</span> <span class="s">(</span><span class="k">defined</span> <span class="i">$TokenNumber</span><span class="s">)</span> <span class="s">{</span>
+ 205       <span class="k">last</span> <span class="j">TOKEN</span><span class="sc">;</span>
+ 206     <span class="s">}</span>
+ 207     <span class="k">else</span> <span class="s">{</span>
+ 208       <span class="k">if</span> <span class="s">(</span><span class="k">defined</span> <span class="i">$TokenLabel</span><span class="s">)</span> <span class="s">{</span>
+ 209         <span class="w">carp</span> <span class="q">&quot;Warning: ${ClassName}-&gt;YYLex: Igorning token label, $TokenLabel, with matched text, $TokenText, returned by lexer and retrieving next available token or text. Token label couldn&#39;t be mapped to token numbers specified in YYTabFile generated from a parser defintion file using byacc. After updating parser definition file, a new YYTabFile containing entry for token label must be generated...&quot;</span><span class="sc">;</span>
+ 210       <span class="s">}</span>
+ 211       <span class="k">else</span> <span class="s">{</span>
+ 212         <span class="w">carp</span> <span class="q">&quot;Warning: ${ClassName}-&gt;YYLex: Igorning token text, $TokenText, returned by lexer and retrieving next available token or text. Token text returned by lexer couldn&#39;t be mapped to token number using Perl ord function. After updating lexer token specifications and parser definition file, a new YYTabFile containing entry for a new token label to match unrecognized text must be generated...  &quot;</span><span class="sc">;</span>
+ 213       <span class="s">}</span>
+ 214       <span class="k">next</span> <span class="j">TOKEN</span><span class="sc">;</span>
+ 215     <span class="s">}</span>
+ 216   <span class="s">}</span>
+ 217 
+ 218   <span class="k">if</span> <span class="s">(</span>!<span class="k">defined</span> <span class="i">$LexerToken</span><span class="s">)</span> <span class="s">{</span>
+ 219     <span class="c"># Chained lexer returns undefined at end of input. So it&#39;s equivalent to EOI</span>
+ 220     <span class="c"># token.</span>
+ 221     <span class="k">if</span> <span class="s">(</span><span class="k">exists</span> <span class="i">$This</span>-&gt;{<span class="w">YYTabDataMap</span>}{<span class="w">EOI</span>}<span class="s">)</span> <span class="s">{</span>
+ 222       <span class="i">$TokenLabel</span> = <span class="q">&quot;EOI&quot;</span><span class="sc">;</span>
+ 223       <span class="i">$TokenNumber</span> = <span class="i">$This</span>-&gt;{<span class="w">YYTabDataMap</span>}{<span class="i">$TokenLabel</span>}<span class="sc">;</span>
+ 224       <span class="i">$TokenText</span> = <span class="q">&quot;0&quot;</span><span class="sc">;</span>
+ 225     <span class="s">}</span>
+ 226     <span class="k">else</span> <span class="s">{</span>
+ 227       <span class="s">(</span><span class="i">$TokenLabel</span><span class="cm">,</span> <span class="i">$TokenNumber</span><span class="cm">,</span> <span class="i">$TokenText</span><span class="s">)</span> = <span class="s">(</span><span class="q">&quot;EOI&quot;</span><span class="cm">,</span> <span class="n">0</span><span class="cm">,</span> <span class="q">&quot;0&quot;</span><span class="s">)</span><span class="sc">;</span>
+ 228     <span class="s">}</span>
+ 229   <span class="s">}</span>
+ 230 
+ 231   <span class="k">return</span> <span class="s">(</span><span class="i">$TokenNumber</span><span class="cm">,</span> <span class="i">$TokenText</span><span class="s">)</span><span class="sc">;</span>
+ 232 <span class="s">}</span>
+ 233 
+ 234 <span class="c"># Get next available token number and text pair from input stream by removing it</span>
+ 235 <span class="c"># from the input stream...</span>
+ 236 <span class="c">#</span>
+<a name="Next-"></a> 237 <span class="k">sub </span><span class="m">Next</span> <span class="s">{</span>
+ 238   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
+ 239 
+ 240   <span class="k">return</span> <span class="i">$This</span><span class="i">-&gt;YYLex</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
+ 241 <span class="s">}</span>
+ 242 
+ 243 <span class="c"># Get next available token number and text pair from input stream by by simply</span>
+ 244 <span class="c"># peeking ahead and without removing it from the input stream...</span>
+ 245 <span class="c">#</span>
+<a name="Peek-"></a> 246 <span class="k">sub </span><span class="m">Peek</span> <span class="s">{</span>
+ 247   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
+ 248 
+ 249   <span class="k">return</span> <span class="i">$This</span><span class="i">-&gt;YYLex</span><span class="s">(</span><span class="q">&#39;Peek&#39;</span><span class="s">)</span>
+ 250 <span class="s">}</span>
+ 251 
+ 252 <span class="c"># Return a curried verson of lexer: yyparse in parser generated by byacc expects it</span>
+ 253 <span class="c"># to call without passing any argument for the YYLexer object...</span>
+ 254 <span class="c">#</span>
+<a name="GetYYLex-"></a> 255 <span class="k">sub </span><span class="m">GetYYLex</span> <span class="s">{</span>
+ 256   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
+ 257 
+ 258   <span class="k">return</span> <span class="k">sub</span> <span class="s">{</span> <span class="k">my</span><span class="s">(</span><span class="i">$Mode</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span> <span class="i">$This</span><span class="i">-&gt;YYLex</span><span class="s">(</span><span class="i">$Mode</span><span class="s">)</span><span class="sc">;</span> <span class="s">}</span><span class="sc">;</span>
+ 259 <span class="s">}</span>
+ 260 
+ 261 <span class="c"># Is it a lexer object?</span>
+<a name="_IsYYLexer-"></a> 262 <span class="k">sub </span><span class="m">_IsYYLexer</span> <span class="s">{</span>
+ 263   <span class="k">my</span><span class="s">(</span><span class="i">$Object</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
+ 264 
+ 265   <span class="k">return</span> <span class="s">(</span><span class="i">Scalar::Util::blessed</span><span class="s">(</span><span class="i">$Object</span><span class="s">)</span> &amp;&amp; <span class="i">$Object</span><span class="i">-&gt;isa</span><span class="s">(</span><span class="i">$ClassName</span><span class="s">)</span><span class="s">)</span> ? <span class="n">1</span> <span class="co">:</span> <span class="n">0</span><span class="sc">;</span>
+ 266 <span class="s">}</span>
+ 267 
+ 268 <span class="c"># Return a string containing information about lexer...</span>
+<a name="StringifyYYLexer-"></a> 269 <span class="k">sub </span><span class="m">StringifyYYLexer</span> <span class="s">{</span>
+ 270   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
+ 271   <span class="k">my</span><span class="s">(</span><span class="i">$YYLexerString</span><span class="s">)</span><span class="sc">;</span>
+ 272 
+ 273   <span class="i">$YYLexerString</span> = <span class="q">&quot;YYLexer: PackageName: $ClassName; &quot;</span> . <span class="i">$This</span><span class="i">-&gt;_GetYYLexerInfoString</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
+ 274 
+ 275   <span class="k">return</span> <span class="i">$YYLexerString</span><span class="sc">;</span>
+ 276 <span class="s">}</span>
+ 277 
+ 278 <span class="c"># Stringigy YYTabFile token name and value information...</span>
+ 279 <span class="c">#</span>
+<a name="_GetYYLexerInfoString-"></a> 280 <span class="k">sub </span><span class="m">_GetYYLexerInfoString</span> <span class="s">{</span>
+ 281   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
+ 282   <span class="k">my</span><span class="s">(</span><span class="i">$YYLexerInfoString</span><span class="cm">,</span> <span class="i">$TokenValue</span><span class="cm">,</span> <span class="i">$YYTabFile</span><span class="cm">,</span> <span class="i">$YYTabFilePath</span><span class="cm">,</span> <span class="i">$YYTabDataMapString</span><span class="s">)</span><span class="sc">;</span>
+ 283 
+ 284   <span class="i">$YYTabFile</span> = <span class="k">defined</span> <span class="i">$This</span>-&gt;{<span class="w">YYTabFile</span>} ? <span class="i">$This</span>-&gt;{<span class="w">YYTabFile</span>} <span class="co">:</span> <span class="q">&#39;None&#39;</span><span class="sc">;</span>
+ 285   <span class="i">$YYTabFilePath</span> = <span class="k">defined</span> <span class="i">$This</span>-&gt;{<span class="w">YYTabFilePath</span>} ? <span class="i">$This</span>-&gt;{<span class="w">YYTabFilePath</span>} <span class="co">:</span> <span class="q">&#39;None&#39;</span><span class="sc">;</span>
+ 286 
+ 287   <span class="i">$YYLexerInfoString</span> = <span class="q">&quot;YYTabFile: $YYTabFile; YYTabFilePath: $YYTabFilePath&quot;</span><span class="sc">;</span>
+ 288 
+ 289   <span class="i">$YYTabDataMapString</span> = <span class="q">&quot;YYTabDataMap: None&quot;</span><span class="sc">;</span>
+ 290   <span class="k">if</span> <span class="s">(</span><span class="k">keys</span> <span class="i">%</span>{<span class="i">$This</span>-&gt;{<span class="w">YYTabDataMap</span>}}<span class="s">)</span> <span class="s">{</span>
+ 291     <span class="k">my</span><span class="s">(</span><span class="i">$TokenLabel</span><span class="cm">,</span> <span class="i">$TokenNumber</span><span class="s">)</span><span class="sc">;</span>
+ 292 
+ 293     <span class="i">$YYTabDataMapString</span> = <span class="q">&quot;YYTabDataMap:&quot;</span><span class="sc">;</span>
+ 294     <span class="k">for</span> <span class="i">$TokenLabel</span> <span class="s">(</span><span class="k">sort</span> <span class="k">keys</span> <span class="i">%</span>{<span class="i">$This</span>-&gt;{<span class="w">YYTabDataMap</span>}}<span class="s">)</span> <span class="s">{</span>
+ 295       <span class="i">$TokenValue</span> = <span class="i">$This</span>-&gt;{<span class="w">YYTabDataMap</span>}{<span class="i">$TokenLabel</span>}<span class="sc">;</span>
+ 296       <span class="i">$YYTabDataMapString</span> .= <span class="q">&quot; ${TokenLabel}=${TokenValue}&quot;</span><span class="sc">;</span>
+ 297     <span class="s">}</span>
+ 298   <span class="s">}</span>
+ 299 
+ 300   <span class="i">$YYLexerInfoString</span> .= <span class="q">&quot;; $YYTabDataMapString; &quot;</span> . <span class="i">$This</span><span class="i">-&gt;_GetLexerInfoString</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
+ 301 
+ 302   <span class="k">return</span> <span class="i">$YYLexerInfoString</span><span class="sc">;</span>
+ 303 <span class="s">}</span>
+ 304 
+<a name="EOF-"></a></pre>
+<p>&nbsp;</p>
+<br />
+<center>
+<img src="../../../images/h2o2.png">
+</center>
+</body>
+</html>