00001 /* $Id: BoolExprParser.h,v 1.12 2005/05/09 02:43:19 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 { 00050 GARBAGE_AT_END, 00051 RUNAWAY_PARENTHESIS, 00052 STRING_EXPECTED 00053 }; 00054 00056 size_t index; 00058 Code code; 00059 00063 Error(size_t i, Code c) : index(i), code(c) {} 00064 }; 00065 00066 00070 BoolExprParser(); 00071 00075 ~BoolExprParser(); 00076 00087 BoolExpr<std::string> *parse(const std::string &expr) throw(Error); 00088 00089 private: 00090 00091 std::string curInput; 00092 size_t curIndex; 00093 00094 // Implementation methods: 00095 BoolExpr<std::string> *parseExpr() throw(Error); 00096 BoolExpr<std::string> *parseTerm() throw(Error); 00097 BoolExpr<std::string> *parseFactor() throw(Error); 00098 BoolExpr<std::string> *parseAtom() throw(Error); 00099 BoolExpr<std::string> *parseString() throw(Error); 00100 00101 bool atEnd(); 00102 bool tokenSeen(const char *s); 00103 void skipToken(const char *s); 00104 void skipSpaces(); 00105 bool isStringChar(char c) const; 00106 00107 // Forbidden operations: 00108 BoolExprParser(const BoolExprParser &); 00109 BoolExprParser &operator = (const BoolExprParser &); 00110 }; 00111 00112 00113 } // namespace boolstuff 00114 00115 00116 #endif /* _H_BoolExprParser */
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