comparison mayachemtools/docs/modules/html/SimpleCalcParser.html @ 0:73ae111cf86f draft

Uploaded
author deepakjadmin
date Wed, 20 Jan 2016 11:55:01 -0500
parents
children
comparison
equal deleted inserted replaced
-1:000000000000 0:73ae111cf86f
1 <html>
2 <head>
3 <title>MayaChemTools:Documentation:Parsers::SimpleCalcParser.pm</title>
4 <meta http-equiv="content-type" content="text/html;charset=utf-8">
5 <link rel="stylesheet" type="text/css" href="../../css/MayaChemTools.css">
6 </head>
7 <body leftmargin="20" rightmargin="20" topmargin="10" bottommargin="10">
8 <br/>
9 <center>
10 <a href="http://www.mayachemtools.org" title="MayaChemTools Home"><img src="../../images/MayaChemToolsLogo.gif" border="0" alt="MayaChemTools"></a>
11 </center>
12 <br/>
13 <div class="DocNav">
14 <table width="100%" border=0 cellpadding=0 cellspacing=2>
15 <tr align="left" valign="top"><td width="33%" align="left"><a href="./Lexer.html" title="Lexer.html">Previous</a>&nbsp;&nbsp;<a href="./index.html" title="Table of Contents">TOC</a>&nbsp;&nbsp;<a href="./SimpleCalcYYLexer.html" title="SimpleCalcYYLexer.html">Next</a></td><td width="34%" align="middle"><strong>Parsers::SimpleCalcParser.pm</strong></td><td width="33%" align="right"><a href="././code/SimpleCalcParser.html" title="View source code">Code</a>&nbsp;|&nbsp;<a href="./../pdf/SimpleCalcParser.pdf" title="PDF US Letter Size">PDF</a>&nbsp;|&nbsp;<a href="./../pdfgreen/SimpleCalcParser.pdf" title="PDF US Letter Size with narrow margins: www.changethemargins.com">PDFGreen</a>&nbsp;|&nbsp;<a href="./../pdfa4/SimpleCalcParser.pdf" title="PDF A4 Size">PDFA4</a>&nbsp;|&nbsp;<a href="./../pdfa4green/SimpleCalcParser.pdf" title="PDF A4 Size with narrow margins: www.changethemargins.com">PDFA4Green</a></td></tr>
16 </table>
17 </div>
18 <p>
19 </p>
20 <h2>NAME</h2>
21 <p>Parsers::SimpleCalcParser</p>
22 <p>
23 </p>
24 <h2>SYNOPSIS</h2>
25 <p>use Parsers::SimpleCalcParser ;</p>
26 <p>use Parsers::SimpleCalcParser qw(:all);</p>
27 <p>
28 </p>
29 <h2>DESCRIPTION</h2>
30 <p><strong>Parsers::SimpleCalcParser</strong> class provides the following methods:</p>
31 <p> <a href="#new">new</a>, <a href="#yyclearin">yyclearin</a>, <a href="#yyerrok">yyerrok</a>, <a href="#yyerror">yyerror</a>, <a href="#yyparse">yyparse</a>
32 </p><p><strong>Parsers::SimpleCalcParse.yy</strong> parser grammer definition file implements a simple
33 calculator and is provided to highlight usage of lexer capability available through
34 <strong>Parsers::SimpleCalcYYLexer</strong>, which in turn uses <strong>Parsers::YYLexer</strong> and
35 <strong>Parsers::Lexer</strong> classes to procide underlying lexer functionality.</p>
36 <p>The parser package and token table files, <strong>Parsers::SimpleCalcParser.pm</strong> and
37 <strong>SimpleCalcParser.tab.ph</strong>, are automatically generated from parser grammar definition
38 file, <strong>Parsers::SimpleCalcParser.yy</strong>, using byacc available through perl-byacc1.8 modified
39 with perl5-byacc-patches-0.5 for generation of object oriented parser:</p>
40 <div class="OptionsBox">
41 byacc -l -P -d -b SimpleCalcParser SimpleCalcParser.yy
42 <br/> mv SimpleCalcParser.tab.pl SimpleCalcParser.pm</div>
43 <p>
44 </p>
45 <h2>METHODS</h2>
46 <dl>
47 <dt><strong><a name="new" class="item"><strong>new</strong></a></strong></dt>
48 <dd>
49 <div class="OptionsBox">
50 $SimpleCalcParser = new Parsers::SimpleCalcParser($YYLex,
51 \&amp;Parsers::SimpleCalcParser::yyerror);
52 <br/> $SimpleCalcParser = new Parsers::SimpleCalcParser($YYLex,
53 \&amp;Parsers::SimpleCalcParser::yyerror, $Debug);</div>
54 <p>Using specified <em>YYLex</em> <em>YYError</em> functions, <strong>new</strong> method generates a new
55 <strong>SimpleCalcParser</strong> and returns a reference to newly created <strong>SimpleCalcYYParser</strong> object.</p>
56 <p>Examples:</p>
57 <div class="OptionsBox">
58 # Input string...
59 <br/> $InputText = &quot;3 + 4 +6\nx=3\ny=5\nx+y\nx+z\n&quot;;
60 <br/> $YYLexer = new Parsers::SimpleCalcYYLexer($InputText);
61 <br/> $YYLex = $YYLexer-&gt;GetYYLex();</div>
62 <div class="OptionsBox">
63 $Debug = 0;
64 <br/> $SimpleCalcParser = new Parsers::SimpleCalcParser($YYLex,
65 \&amp;Parsers::SimpleCalcParser::yyerror, $Debug);
66 <br/> $Value = $SimpleCalcParser-&gt;yyparse();
67 <br/> print &quot;Value = &quot; . (defined($Value) ? &quot;$Value&quot; : &quot;Undefined&quot;) . &quot;\n&quot;;</div>
68 <div class="OptionsBox">
69 # Input file...
70 <br/> $InputFile = &quot;TestSimpleCalcParser.txt&quot;;
71 <br/> open INPUTFILE, &quot;$InputFile&quot; or die &quot;Couldn't open $InputFile: $!\n&quot;;</div>
72 <div class="OptionsBox">
73 $YYLexer = new Parsers::SimpleCalcYYLexer(\*INPUTFILE);
74 <br/> $YYLex = $YYLexer-&gt;GetYYLex();</div>
75 <div class="OptionsBox">
76 $Debug = 0;
77 <br/> $SimpleCalcParser = new Parsers::SimpleCalcParser($YYLex,
78 \&amp;Parsers::SimpleCalcParser::yyerror, $Debug);
79 <br/> $Value = $SimpleCalcParser-&gt;yyparse();
80 <br/> print &quot;Value = &quot; . (defined($Value) ? &quot;$Value&quot; : &quot;Undefined&quot;) . &quot;\n&quot;;</div>
81 <div class="OptionsBox">
82 close INPUTFILE;</div>
83 <div class="OptionsBox">
84 # Input iterator...
85 <br/> $InputFile = &quot;TestSimpleCalcParser.txt&quot;;
86 <br/> open INPUTFILE, &quot;$InputFile&quot; or die &quot;Couldn't open $InputFile: $!\n&quot;;
87 <br/> $InputIterator = sub { return &lt;INPUTFILE&gt;; };</div>
88 <div class="OptionsBox">
89 $YYLexer = new Parsers::SimpleCalcYYLexer($InputIterator);
90 <br/> $YYLex = $YYLexer-&gt;GetYYLex();</div>
91 <div class="OptionsBox">
92 $Debug = 0;
93 <br/> $SimpleCalcParser = new Parsers::SimpleCalcParser($YYLex,
94 \&amp;Parsers::SimpleCalcParser::yyerror, $Debug);
95 <br/> $Value = $SimpleCalcParser-&gt;yyparse();
96 <br/> print &quot;Value = &quot; . (defined($Value) ? &quot;$Value&quot; : &quot;Undefined&quot;) . &quot;\n&quot;;</div>
97 <div class="OptionsBox">
98 close INPUTFILE;</div>
99 </dd>
100 <dt><strong><a name="yyclearin" class="item"><strong>yyclearin</strong></a></strong></dt>
101 <dd>
102 <div class="OptionsBox">
103 $SimpleCalcParser-&gt;yyclearin();</div>
104 <p><strong>yyclearin</strong> method clears any previous look-ahead token after encountering a syntax error
105 during parsing. It can be used after <strong>yyerrok</strong> in a grammer rule with the reserved word
106 <strong>error</strong>.</p>
107 </dd>
108 <dt><strong><a name="yyerrok" class="item"><strong>yyerrok</strong></a></strong></dt>
109 <dd>
110 <div class="OptionsBox">
111 $SimpleCalcParser-&gt;yyerrok();</div>
112 <p><strong>yyerrok</strong> method is used with the reserved word <strong>error</strong> in grammer rule to indcate
113 error recovery is complete after encountering a syntax error during parsing.</p>
114 </dd>
115 <dt><strong><a name="yyerror" class="item"><strong>yyerror</strong></a></strong></dt>
116 <dd>
117 <div class="OptionsBox">
118 $SimpleCalcParser-&gt;yyerror();</div>
119 <p><strong>yyerror</strong> function is provided for the caller to use during initialization of a parser. It
120 is used by <strong>yyparse</strong> to print any error messages encountered during parsing of the
121 input.</p>
122 </dd>
123 <dt><strong><a name="yyparse" class="item"><strong>yyparse</strong></a></strong></dt>
124 <dd>
125 <div class="OptionsBox">
126 $Value = $SimpleCalcParser-&gt;yyparse();</div>
127 <p>Returns <em>Value</em> after parsing all the input from a input stream using specified
128 grammer rules.</p>
129 </dd>
130 </dl>
131 <p>
132 </p>
133 <h2>AUTHOR</h2>
134 <p><a href="mailto:msud@san.rr.com">Manish Sud</a></p>
135 <p>
136 </p>
137 <h2>SEE ALSO</h2>
138 <p><a href="./Lexer.html">Lexer.pm</a>,&nbsp<a href="./YYLexer.html">YYLexer.pm</a>,&nbsp<a href="./SimpleCalcYYLexer.html">SimpleCalcYYLexer.pm</a>
139 </p>
140 <p>
141 </p>
142 <h2>COPYRIGHT</h2>
143 <p>Copyright (C) 2015 Manish Sud. All rights reserved.</p>
144 <p>This file is part of MayaChemTools.</p>
145 <p>MayaChemTools is free software; you can redistribute it and/or modify it under
146 the terms of the GNU Lesser General Public License as published by the Free
147 Software Foundation; either version 3 of the License, or (at your option)
148 any later version.</p>
149 <p>&nbsp</p><p>&nbsp</p><div class="DocNav">
150 <table width="100%" border=0 cellpadding=0 cellspacing=2>
151 <tr align="left" valign="top"><td width="33%" align="left"><a href="./Lexer.html" title="Lexer.html">Previous</a>&nbsp;&nbsp;<a href="./index.html" title="Table of Contents">TOC</a>&nbsp;&nbsp;<a href="./SimpleCalcYYLexer.html" title="SimpleCalcYYLexer.html">Next</a></td><td width="34%" align="middle"><strong>March 29, 2015</strong></td><td width="33%" align="right"><strong>Parsers::SimpleCalcParser.pm</strong></td></tr>
152 </table>
153 </div>
154 <br />
155 <center>
156 <img src="../../images/h2o2.png">
157 </center>
158 </body>
159 </html>