/* Interface for NSExpression for GNUStep
   Copyright (C) 2005 Free Software Foundation, Inc.

   Written by:  Dr. H. Nikolaus Schaller
   Created: 2005
   
   This file is part of the GNUstep Base Library.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 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
   Library General Public License for more details.
   
   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02111 USA.
   */ 

#ifndef __NSExpression_h_GNUSTEP_BASE_INCLUDE
#define __NSExpression_h_GNUSTEP_BASE_INCLUDE

#include <Foundation/NSPredicate.h>

@class NSMutableDictionary;

typedef enum _NSExpressionType
{
  NSConstantValueExpressionType=0,
  NSEvaluatedObjectExpressionType,
  NSVariableExpressionType,
  NSKeyPathExpressionType,
  NSFunctionExpressionType
} NSExpressionType;

@interface NSExpression : NSObject <NSCoding, NSCopying>

+ (NSExpression *) expressionForConstantValue: (id)obj;
+ (NSExpression *) expressionForEvaluatedObject;
+ (NSExpression *) expressionForFunction: (NSString *)name
			       arguments: (NSArray *)args;
+ (NSExpression *) expressionForKeyPath: (NSString *)path;
+ (NSExpression *) expressionForVariable: (NSString *)string;

- (NSArray *) arguments;
- (id) constantValue;
- (NSExpressionType) expressionType;
- (id) expressionValueWithObject: (id)object
			 context: (NSMutableDictionary *)context;
- (NSString *) function;
- (id) initWithExpressionType: (NSExpressionType) type;
- (NSString *) keyPath;
- (NSExpression *) operand;
- (NSString *) variable;

@end
#endif /* __NSExpression_h_GNUSTEP_BASE_INCLUDE */

