//
//  MPExpressionEvaluator.h
//  MathPad
//
//  Created by Kim Wittenburg on 31.08.14.
//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "MPExpression.h"
#import "MPExpressionTokenizer.h"
#import "MPTerm.h"

@class MPExpressionEvaluator, MPExpression, MPParsedElementOld;

@interface MPExpressionEvaluator : NSObject

// Do not instanciate yourself, use evaluator property of MPExpression instead
- (instancetype)initWithExpression:(MPExpression *)expression;
@property (readonly, nonatomic, weak) MPExpression *expression;

@property (nonatomic, strong) MPExpressionTokenizer *lexer;

- (void)expressionDidChangeInRange:(NSRange)range
                 replacementLength:(NSUInteger)replacementLength;

#pragma mark Evaluating Expressions
@property (readonly, nonatomic, copy) NSString *definedVariable;

- (MPTerm *)parseExpectingVariable:(BOOL)flag error:(MPParseError *__autoreleasing *)error;

@end