Anyone done an Objective-C Xode version of Osherove´s TDD Kata “String Calculator”?

Question

Always trying to code better and I am interested in doing TDD for Objective-C and Xcode.
Do you know any post that implement something like Roy Osherove´s \"String Calc

Answer 1

I'd use NSPredicate like this:

NSPredicate * parsed = [NSPredicate predicateWithFormat:@"6 * 7 = 0"];
NSExpression * left = [(NSComparisonPredicate *)parsed leftExpression];
NSNumber * result = [left expressionValueWithObject:nil context:nil];
NSLog(@"result: %@", result);

Look here for more info on using NSPredicate in weird ways.