Added Evaluation Context and Math Rules

MathPad/MPMathRules.h

@@ -0,0 +1,28 @@
+//
+//  MPMathRules.h
+//  MathPad
+//
+//  Created by Kim Wittenburg on 14.09.14.
+//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+FOUNDATION_EXPORT NSString *MPMathRulesAllowsImplicitMultiplicationKey;
+FOUNDATION_EXPORT NSString *MPMathRulesMaximumOperatorChainLengthKey;
+FOUNDATION_EXPORT NSString *MPMathRulesMaximumOperatorChainLengthInMultiplicationKey;
+FOUNDATION_EXPORT NSString *MPMathRulesMaximumOperatorChainLengthInFunctionKey;
+
+@interface MPMathRules : NSObject
+
++ (MPMathRules *)sharedRules;
+
+@property (nonatomic, getter = isUsingUserDefaultValues) BOOL usingUserDefaultValues;
+
+@property (nonatomic) BOOL allowsImplicitMultiplication; // wether 2 3 is equal to 6 or error
+// Default value uses the key "..." in NSUserDefaults or ... if the key does not exist.
+@property (nonatomic) NSUInteger maximumOperatorChainLength; // +--++-5 -> Chain length: 6, 2 default (sign of number and operator) (0 is invalid?)
+@property (nonatomic) NSUInteger maximumOperatorChainLengthInMultiplication; // Default: 1, 0 means actually 0
+@property (nonatomic) NSUInteger maximumOperatorChainLengthInFunction; // For sin, cos, tan. Default: 1
+
+@end