Implemented Evaluation

MathPad/MPParsedElement.m

@@ -14,46 +14,109 @@
 {
     self = [super init];
     if (self) {
-        _summands = [[NSMutableArray alloc] init];
     }
     return self;
 }
 
-- (double)standaloneValue
+- (NSDecimalNumber *)valueAtBeginning
+{
+    NSDecimalNumber *value = self.value;
+    if (self.prefixValueExplicit) {
+        value = [value decimalNumberByAdding:self.prefixMultiplicator];
+    }
+    return value;
+}
+
+- (NSDecimalNumber *)valueAtEnd
+{
+    NSDecimalNumber *value = self.value;
+    if (self.suffixValueExplicit) {
+        value = [value decimalNumberByAdding:self.suffixMultiplicator];
+    }
+    return value;
+}
+
+- (NSDecimalNumber *)standaloneValue
 {
     if (self.isFactor) {
-        return self.factor;
+        return self.value;
     }
-    return self.prefixMultiplicator + [[self.summands valueForKeyPath:@"@sum.self"] doubleValue];
+    NSDecimalNumber *value = self.value;
+    if (self.prefixValueExplicit) {
+        value = [value decimalNumberByAdding:self.prefixMultiplicator];
+    }
+    if (self.suffixValueExplicit) {
+        value = [value decimalNumberByAdding:self.suffixMultiplicator];
+    }
+    return value;
 }
 
-- (BOOL)isValidElementAtBeginning
-{
-    return NO;
-}
-
-- (BOOL)isValidElementInBetween
+- (BOOL)isValidElementAtBeginning:(MPParseError *__autoreleasing *)error
 {
+    if (self.prefixOperatorExplicit) {
+        if (error) {
+            *error = MPParseError(0, @"Expected Number");
+        }
+        return NO;
+    }
     return YES;
 }
 
-- (BOOL)isValidElementAtEnd
+- (BOOL)isValidStandaloneElement:(MPParseError *__autoreleasing *)error
 {
-    return NO;
+    return [self isValidElementAtBeginning:error] && [self isValidElementAtEnd:error];
 }
 
-#pragma mark NSCopying
+- (BOOL)isValidElementAtEnd:(MPParseError *__autoreleasing *)error
+{
+    if (self.suffixOperatorExplicit) {
+        if (error) {
+            *error = MPParseError(self.suffixIndex, @"Expected Number");
+        }
+        return NO;
+    }
+    return YES;
+}
+
+- (BOOL)isValidVariableDefinition:(MPParseError *__autoreleasing *)error
+{
+    if (self.definedVariable == nil) {
+        if (error) {
+            *error = MPParseError(0, @"Expected Variable Definition");
+        }
+        return NO;
+    }
+    return [self isValidElementAtBeginning:error];
+}
+
+#pragma mark - NSObject Overrides
+
+- (NSString *)description
+{
+    NSMutableString *description = [[NSMutableString alloc] initWithString:@"MPParsedElement<"];
+    if (self.isFactor) {
+        [description appendFormat:@"factor=%@%@%@", self.prefixOperatorExplicit?@"*":@"", self.value, self.suffixOperatorExplicit?@"*":@""];
+    } else {
+        [description appendFormat:@"prefix=%@%@ prefixValueExplicit=%@", self.prefixOperatorExplicit?@"*":@"", self.prefixMultiplicator, self.prefixValueExplicit?@"YES":@"NO"];
+        [description appendFormat:@" suffix=%@%@ suffixValueExplicit=%@", self.suffixMultiplicator, self.suffixOperatorExplicit?@"*":@"", self.suffixValueExplicit?@"YES":@"NO"];
+        [description appendFormat:@" value=%@", self.value];
+    }
+    [description appendString:@">"];
+    return [description copy];
+}
+
+#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.value = self.value;
     copy.prefixOperatorExplicit = self.prefixOperatorExplicit;
+    copy.prefixValueExplicit = self.prefixValueExplicit;
+    copy.prefixMultiplicator = self.prefixMultiplicator;
+    copy.suffixOperatorExplicit = self.suffixOperatorExplicit;
+    copy.suffixValueExplicit = self.suffixValueExplicit;
     copy.suffixMultiplicator = self.suffixMultiplicator;
-    copy.hasSuffixMultiplicator = self.hasSuffixMultiplicator;
     return copy;
 }