Started to Implement the Parser

MathPad/MPParsedElement.m

@@ -0,0 +1,60 @@
+//
+//  MPParsedElement.m
+//  MathPad
+//
+//  Created by Kim Wittenburg on 05.09.14.
+//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
+//
+
+#import "MPParsedElement.h"
+
+@implementation MPParsedElement
+
+- (instancetype)init
+{
+    self = [super init];
+    if (self) {
+        _summands = [[NSMutableArray alloc] init];
+    }
+    return self;
+}
+
+- (double)standaloneValue
+{
+    if (self.isFactor) {
+        return self.factor;
+    }
+    return self.prefixMultiplicator + [[self.summands valueForKeyPath:@"@sum.self"] doubleValue];
+}
+
+- (BOOL)isValidElementAtBeginning
+{
+    return NO;
+}
+
+- (BOOL)isValidElementInBetween
+{
+    return YES;
+}
+
+- (BOOL)isValidElementAtEnd
+{
+    return NO;
+}
+
+#pragma mark NSCopying
+- (id)copyWithZone:(NSZone *)zone
+{
+    MPParsedElement *copy = [[MPParsedElement allocWithZone:zone] init];
+    copy.isFactor = self.isFactor;
+    copy.factor = self.factor;
+    copy.summands = self.summands.mutableCopy;
+    copy.prefixMultiplicator = self.prefixMultiplicator;
+    copy.hasPrefixMultiplicator = self.hasPrefixMultiplicator;
+    copy.prefixOperatorExplicit = self.prefixOperatorExplicit;
+    copy.suffixMultiplicator = self.suffixMultiplicator;
+    copy.hasSuffixMultiplicator = self.hasSuffixMultiplicator;
+    return copy;
+}
+
+@end