/* 
   EOExpressionArray.h

   Copyright (C) 1996 Free Software Foundation, Inc.

   Author: Ovidiu Predescu <ovidiu@bx.logicnet.ro>
   Date: September 1996

   This file is part of the GNUstep Database 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; see the file COPYING.LIB.
   If not, write to the Free Software Foundation,
   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/

#ifndef __EOExpressionArray_h__
#define __EOExpressionArray_h__


#import <Foundation/NSString.h>
#import <gnustep/base/GCObject.h>


@class NSArray;

@class EOAttribute;
@class EOEntity;
@class EOSQLExpression;


@protocol EOExpressionContext <NSObject>

- (NSString *)expressionValueForAttribute: (EOAttribute *)anAttribute;
- (NSString *)expressionValueForAttributePath: (NSArray *)path;

@end


@interface EOExpressionArray : GCMutableArray
{
  NSString *_prefix;
  NSString *_infix;
  NSString *_suffix;
//    NSString *_definition; it's rebuilt
  EOAttribute *_realAttribute;

  struct
  {
    unsigned int isFlattened:1; //TODO Why ?
  } _flags;
}

+ (EOExpressionArray*)expressionArray;
+ (EOExpressionArray*)expressionArrayWithPrefix: (NSString *)prefix
                                          infix: (NSString *)infix
                                         suffix: (NSString *)suffix;

/* Initializing instances */
- initWithPrefix: (NSString *)prefix
           infix: (NSString *)infix
          suffix: (NSString *)suffix;

- (NSString *)prefix;
- (NSString *)infix;
- (NSString *)suffix;

- (NSString *)definition;
- (BOOL)isFlattened;
- (EOAttribute *)realAttribute;

/* Accessing the components */
- (void)setPrefix: (NSString*)prefix;
- (void)setInfix: (NSString*)infix;
- (void)setSuffix: (NSString*)suffix;

/* Checking contents */
- (BOOL)referencesObject: (id)anObject;

- (NSString *)expressionValueForContext: (id<EOExpressionContext>)ctx;

+ (EOExpressionArray *)parseExpression: (NSString *)expression
                                entity: (EOEntity *)entity
             replacePropertyReferences: (BOOL)flag;

- (NSString*)valueForSQLExpression: (EOSQLExpression *)sqlExpression;

@end /* EOExpressionArray */


@interface NSObject (EOExpression)
- (NSString*)expressionValueForContext: (id<EOExpressionContext>)context;
@end


@interface NSString (EOAttributeTypeCheck)

- (BOOL)isNameOfARelationshipPath;

@end

#endif /* __EOExpressionArray_h__ */