1 package Parsers::SimpleCalcYYLexer;
   2 #
   3 # File: SimpleCalcYYLexer.pm
   4 # Author: Manish Sud <msud@san.rr.com>
   5 #
   6 # Copyright (C) 2024 Manish Sud. All rights reserved.
   7 #
   8 # This file is part of MayaChemTools.
   9 #
  10 # MayaChemTools is free software; you can redistribute it and/or modify it under
  11 # the terms of the GNU Lesser General Public License as published by the Free
  12 # Software Foundation; either version 3 of the License, or (at your option) any
  13 # later version.
  14 #
  15 # MayaChemTools is distributed in the hope that it will be useful, but without
  16 # any warranty; without even the implied warranty of merchantability of fitness
  17 # for a particular purpose.  See the GNU Lesser General Public License for more
  18 # details.
  19 #
  20 # You should have received a copy of the GNU Lesser General Public License
  21 # along with MayaChemTools; if not, see <http://www.gnu.org/licenses/> or
  22 # write to the Free Software Foundation Inc., 59 Temple Place, Suite 330,
  23 # Boston, MA, 02111-1307, USA.
  24 #
  25 
  26 use strict;
  27 use Carp;
  28 use Exporter;
  29 use Scalar::Util ();
  30 use Parsers::YYLexer;
  31 
  32 use vars qw(@ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
  33 
  34 @ISA = qw(Parsers::YYLexer Exporter);
  35 @EXPORT = qw();
  36 @EXPORT_OK = qw();
  37 
  38 %EXPORT_TAGS = (all  => [@EXPORT, @EXPORT_OK]);
  39 
  40 # Setup class variables...
  41 my($ClassName, $YYTabFile, @YYLexerTokensSpec);
  42 _InitializeClass();
  43 
  44 # Overload Perl functions...
  45 use overload '""' => 'StringifySimpleCalcYYLexer';
  46 
  47 # Class constructor...
  48 sub new {
  49   my($Class, $Input) = @_;
  50   my(@TokensSpec);
  51 
  52   # Initialize object...
  53   my $This = $Class->SUPER::new($Input,  @YYLexerTokensSpec);
  54   bless $This, ref($Class) || $Class;
  55   $This->_InitializeYYLexer();
  56 
  57   return $This;
  58 }
  59 
  60 # Initialize object data...
  61 #
  62 sub _InitializeYYLexer {
  63   my($This) = @_;
  64 
  65   # Setup default YYTabFile containing mapping of token names to numbers...
  66   $This->SetupYYTabFile($YYTabFile);
  67 
  68   return $This;
  69 }
  70 
  71 # Initialize class ...
  72 sub _InitializeClass {
  73   #Class name...
  74   $ClassName = __PACKAGE__;
  75 
  76   # Setup default token table file...
  77   $YYTabFile = "Parsers/SimpleCalcParser.tab.ph";
  78 
  79   # Setup default lexer tokens specs...
  80   @YYLexerTokensSpec = (
  81                         [ 'LETTER', qr/[a-zA-Z]/ ],
  82                         [ 'NUMBER', qr/\d+/ ],
  83                         [ 'SPACE', qr/[ ]*/, sub { my($This, $TokenLabel, $MatchedText) = @_; return ''; } ],
  84                         [ 'NEWLINE', qr/(?:\r\n|\r|\n)/, sub { my($This, $TokenLabel, $MatchedText) = @_;  return "\n"; } ],
  85                         [ 'CHAR', qr/./ ]
  86                        );
  87 }
  88 
  89 # Is it a lexer object?
  90 sub _IsSimpleCalcYYLexer {
  91   my($Object) = @_;
  92 
  93   return (Scalar::Util::blessed($Object) && $Object->isa($ClassName)) ? 1 : 0;
  94 }
  95 
  96 # Return a string containing information about lexer...
  97 sub StringifySimpleCalcYYLexer {
  98   my($This) = @_;
  99   my($SimleCalcYYLexerString);
 100 
 101   $SimleCalcYYLexerString = "SimpleCalcYYLexer: PackageName: $ClassName; " . $This->_GetYYLexerInfoString();
 102 
 103   return $SimleCalcYYLexerString;
 104 }
 105