// Copyright 2015 Google Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#import <Foundation/Foundation.h>

#import "Expression.h"

typedef enum {
  kAdd,
  kSubtract,
  kMultiply,
  kDivide
} Operation;

@interface Equation : Expression

@property (nonatomic, assign) Operation operation;

- (id)initWithOperation:(Operation)operation;
- (NSArray *)children;
- (void)addExpressionAsChild:(Expression *)child;

@end