Added the MPExpressionTree Classes

MathPad/MPFactor.m

@@ -0,0 +1,95 @@
+//
+//  MPFactor.m
+//  MathPad
+//
+//  Created by Kim Wittenburg on 09.10.14.
+//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
+//
+
+#import "MPFactor.h"
+#import "MPMathRules.h"
+
+@implementation MPFactor {
+    NSRange _multiplicationSymbolRange;
+}
+
+- (instancetype)init
+{
+    self = [super init];
+    if (self) {
+        
+    }
+    return self;
+}
+
+- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
+{
+    self = [self init];
+    if (self) {
+        [tokenStream beginIgnoringWhitespaceTokens];
+        MPToken *token = tokenStream.currentToken;
+        if (token.tokenType == MPMultiplicationSymbolToken) {
+            _multiplicationSymbolRange = token.range;
+            [tokenStream currentTokenConsumed];
+        } else {
+            _multiplicationSymbolRange = NSMakeRange(NSNotFound, 0);
+        }
+        if (tokenStream.currentToken.tokenType == MPOperatorListToken) {
+            _operatorChain = [[MPOperatorChain alloc] initWithTokenStream:tokenStream];
+        }
+        MPValueGroup *valueGroup = [[MPValueGroup alloc] initWithTokenStream:tokenStream];
+        _value = [tokenStream consumeSuffixesForValue:valueGroup];
+        [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
+    }
+    return self;
+}
+
+- (NSRange)range
+{
+    if (_multiplicationSymbolRange.location == NSNotFound) {
+        return self.value.range;
+    }
+    return NSUnionRange(_multiplicationSymbolRange, self.value.range);
+}
+
+- (NSRange)multiplicationSymbolRange
+{
+    return _multiplicationSymbolRange;
+}
+
+- (BOOL)hasMultiplicationSymbol
+{
+    return _multiplicationSymbolRange.location != NSNotFound;
+}
+
+- (BOOL)validate:(MPParseError *__autoreleasing *)error
+{
+    if (self.operatorChain.numberOfOperators > [[MPMathRules sharedRules] maximumOperatorChainLengthInMultiplication]) {
+        if (error) {
+            *error = MPParseError(self.operatorChain.range, @"Too many operators in Multiplication");
+        }
+        return NO;
+    }
+    return [self.value validate:error];
+}
+
+- (NSDecimalNumber *)evaluate
+{
+    NSDecimalNumber *value = [self.value evaluate];
+    if ([value isNotEqualTo:[NSDecimalNumber notANumber]] && self.operatorChain) {
+        value = [value decimalNumberByMultiplyingBy:[self.operatorChain evaluate]];
+    }
+    return value;
+}
+
+- (NSArray *)expressionElements
+{
+    NSMutableArray *elements = [[NSMutableArray alloc] init];
+    if (self.hasMultiplicationSymbol) {
+        [elements addObject:@"*"];
+    }
+    [elements addObjectsFromArray:self.value.expressionElements];
+    return elements;
+}
+
+@end