//
//  MPExpressionTreeElement.h
//  MathPad
//
//  Created by Kim Wittenburg on 09.10.14.
//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "MPTokenStream.h"
#import "MPParseError.h"
#import "MPTokenStream.h"

#define MPTokenStreamRecordCurrentLocation(tokenStream) NSUInteger __tokenStreamStart = tokenStream.currentToken.range.location
#define MPTokenStreamRecordedRange(tokenStream) NSMakeRange(__tokenStreamStart, tokenStream.currentToken.range.location - __tokenStreamStart)

@protocol MPExpressionTreeElement <NSObject>
@required

- (instancetype)init;
- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream;

- (NSRange)range;

- (BOOL)validate:(MPParseError *__autoreleasing *)error;
- (NSDecimalNumber *)evaluate;

- (NSArray *)expressionElements; // Converts

@end