use Parsers::SimpleCalcParser ;
use Parsers::SimpleCalcParser qw(:all);
Parsers::SimpleCalcParser class provides the following methods:
new, yyclearin, yyerrok, yyerror, yyparse
Parsers::SimpleCalcParse.yy parser grammer definition file implements a simple calculator and is provided to highlight usage of lexer capability available through Parsers::SimpleCalcYYLexer, which in turn uses Parsers::YYLexer and Parsers::Lexer classes to procide underlying lexer functionality.
The parser package and token table files, Parsers::SimpleCalcParser.pm and SimpleCalcParser.tab.ph, are automatically generated from parser grammar definition file, Parsers::SimpleCalcParser.yy, using byacc available through perl-byacc1.8 modified with perl5-byacc-patches-0.5 for generation of object oriented parser:
Using specified YYLex YYError functions, new method generates a new SimpleCalcParser and returns a reference to newly created SimpleCalcYYParser object.
yyclearin method clears any previous look-ahead token after encountering a syntax error during parsing. It can be used after yyerrok in a grammer rule with the reserved word error.
yyerrok method is used with the reserved word error in grammer rule to indcate error recovery is complete after encountering a syntax error during parsing.
yyerror function is provided for the caller to use during initialization of a parser. It is used by yyparse to print any error messages encountered during parsing of the input.
Returns Value after parsing all the input from a input stream using specified grammer rules.
Lexer.pm, YYLexer.pm, SimpleCalcYYLexer.pm
Copyright (C) 2017 Manish Sud. All rights reserved.
This file is part of MayaChemTools.
MayaChemTools is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.