00001 /* $Id: BoolExprParser.h,v 1.14 2008/10/07 02:29:03 sarrazip Exp $ 00002 BoolExprParser.h - Boolean expression parser and syntax tree builder 00003 00004 boolstuff - Disjunctive Normal Form boolean expression library 00005 Copyright (C) 2002-2005 Pierre Sarrazin <http://sarrazip.com/> 00006 00007 This program is free software; you can redistribute it and/or 00008 modify it under the terms of the GNU General Public License 00009 as published by the Free Software Foundation; either version 2 00010 of the License, or (at your option) any later version. 00011 00012 This program is distributed in the hope that it will be useful, 00013 but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00015 GNU General Public License for more details. 00016 00017 You should have received a copy of the GNU General Public License 00018 along with this program; if not, write to the Free Software 00019 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 00020 02111-1307, USA. 00021 */ 00022 00023 #ifndef _H_BoolExprParser 00024 #define _H_BoolExprParser 00025 00026 #include <boolstuff/BoolExpr.h> 00027 00028 #include <string> 00029 00030 00031 namespace boolstuff { 00032 00033 00039 class BoolExprParser 00040 { 00041 public: 00042 00044 class Error 00045 { 00046 public: 00048 enum Code 00049 { 00053 GARBAGE_AT_END, 00054 00058 RUNAWAY_PARENTHESIS, 00059 00064 IDENTIFIER_EXPECTED, 00065 00068 STRING_EXPECTED = IDENTIFIER_EXPECTED 00069 }; 00070 00072 size_t index; 00073 00075 Code code; 00076 00080 Error(size_t i, Code c) : index(i), code(c) {} 00081 }; 00082 00083 00087 BoolExprParser(); 00088 00092 ~BoolExprParser(); 00093 00104 BoolExpr<std::string> *parse(const std::string &expr) throw(Error); 00105 00106 private: 00107 00108 std::string curInput; 00109 size_t curIndex; 00110 00111 // Implementation methods: 00112 BoolExpr<std::string> *parseExpr() throw(Error); 00113 BoolExpr<std::string> *parseTerm() throw(Error); 00114 BoolExpr<std::string> *parseFactor() throw(Error); 00115 BoolExpr<std::string> *parseAtom() throw(Error); 00116 BoolExpr<std::string> *parseIdentifier() throw(Error); 00117 00118 bool atEnd(); 00119 bool tokenSeen(const char *s); 00120 void skipToken(const char *s); 00121 void skipSpaces(); 00122 bool isIdentifierChar(char c) const; 00123 00124 // Forbidden operations: 00125 BoolExprParser(const BoolExprParser &); 00126 BoolExprParser &operator = (const BoolExprParser &); 00127 }; 00128 00129 00130 } // namespace boolstuff 00131 00132 00133 #endif /* _H_BoolExprParser */
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