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/********************************************************************************
* *
* E x p r e s s i o n E v a l u a t o r *
* *
*********************************************************************************
* Copyright (C) 1998,2006 by Jeroen van der Zijp. All Rights Reserved. *
*********************************************************************************
* This library 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 2.1 of the License, or (at your option) any later version. *
* *
* This library is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public *
* License along with this library; if not, write to the Free Software *
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. *
*********************************************************************************
* $Id: FXExpression.h 2401 2006-04-27 00:46:49Z lyle $ *
********************************************************************************/
#ifndef FXEXPRESSION_H
#define FXEXPRESSION_H
namespace FX {
/// Expression error codes
enum FXExpressionError {
EXPRERR_OK,
EXPRERR_EMPTY, /// Empty input
EXPRERR_MEMORY, /// Out of memory
EXPRERR_PAREN, /// Unmatched parentheses
EXPRERR_TOKEN, /// Illegal token
EXPRERR_COMMA, /// Expected comma
EXPRERR_IDENT /// Unknown identifier
};
/// Expression
class FXAPI FXExpression {
private:
FXuchar *code;
private:
static const FXuchar initial[];
static const FXchar *const errors[];
public:
/// Construct empty expression object
FXExpression();
/// Copy expression object
FXExpression(const FXExpression& orig);
/// Compile expression; if error is not NULL, error code is returned
FXExpression(const FXchar* expression,const FXchar* variables=NULL,FXExpressionError* error=NULL);
/// Compile expression; if error is not NULL, error code is returned
FXExpression(const FXString& expression,const FXString& variables=FXString::null,FXExpressionError* error=NULL);
/// Assign another expression to this one
FXExpression& operator=(const FXExpression& orig);
/// See if expression is empty
bool empty() const { return (code==initial); }
/// Evaluate expression with given arguments, if any
FXdouble evaluate(const FXdouble *args=NULL);
/// Parse expression, return error code if syntax error is found
FXExpressionError parse(const FXchar* expression,const FXchar* variables=NULL);
/// Parse expression, return error code if syntax error is found
FXExpressionError parse(const FXString& expression,const FXString& variables=FXString::null);
/// Returns error code for given error
static const FXchar* getError(FXExpressionError err){ return errors[err]; }
/// Delete
~FXExpression();
};
}
#endif