1 /*****************************************************************************
3 *****************************************************************************
4 * Copyright (C) 2004 the VideoLAN team
7 * Authors: Cyril Deguet <asmax@via.ecp.fr>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22 *****************************************************************************/
24 #ifndef EXPR_EVALUATOR_HPP
25 #define EXPR_EVALUATOR_HPP
27 #include "../src/skin_common.hpp"
31 /// Expression evaluator using Reverse Polish Notation
32 class ExprEvaluator: public SkinObject
36 ExprEvaluator( intf_thread_t *pIntf ): SkinObject( pIntf ) {}
41 /// Clear the RPN stack and parse an expression
42 void parse( const string &rExpr );
44 /// Pop the first token from the RPN stack.
45 /// Return NULL when the stack is empty.
52 /// Returns true if op1 has precedency over op2
53 bool hasPrecedency( const string &op1, const string &op2 ) const;