Drastic Simplification of MPFunction subclass implementations

MathPad/MPParenthesisFunction.m

@@ -12,49 +12,18 @@
 
 @implementation MPParenthesisFunction
 
-+ (NSString *)localizedFunctionName
-{
-    return NSLocalizedString(@"Parenthesis", @"Name of Parenthesis Function");
-}
+MPFunctionAccessorImplementation(Expression, _expression)
 
-- (instancetype)init
-{
-    self = [super init];
-    if (self) {
-        _expression = [[MPExpression alloc] init];
-        _expression.parent = self;
-    }
-    return self;
-}
+//- (void)setExpression:(MPExpression *)expression
+//{
+//    _expression.parent = nil;
+//    _expression = expression;
+//    _expression.parent = self;
+//}
 
-- (void)setExpression:(MPExpression *)expression
+- (NSArray *)childrenAccessors
 {
-    _expression.parent = nil;
-    _expression = expression;
-    _expression.parent = self;
-}
-
-- (NSUInteger)numberOfChildren
-{
-    return 1;
-}
-
-- (MPExpression *)childAtIndex:(NSUInteger)index
-{
-    return index == 0 ? self.expression : nil;
-}
-
-- (void)setChild:(MPExpression *)child
-         atIndex:(NSUInteger)index
-{
-    if (index == 0) {
-        self.expression = child;
-    }
-}
-
-- (NSArray *)children
-{
-    return @[self.expression];
+    return @[@"expression"];
 }
 
 - (MPTerm *)parseWithError:(MPParseError *__autoreleasing *)error
@@ -64,27 +33,9 @@
                                        error:error];
 }
 
-- (NSDecimalNumber *)evaluateWithError:(MPParseError *__autoreleasing *)error
-{
-    return [self.expression evaluateWithError:error];
-}
-
 - (NSString *)description
 {
     return [NSString stringWithFormat:@"(%@)", self.expression.description];
 }
 
-- (NSUInteger)hash
-{
-#warning Unimplemented Method
-    return [super hash] * self.expression.hash;
-}
-
-- (id)copyWithZone:(NSZone *)zone
-{
-    MPParenthesisFunction *copy = [[MPParenthesisFunction allocWithZone:zone] init];
-    copy.expression = self.expression.copy;
-    return copy;
-}
-
 @end