Am 14.08.2014 21:34, schrieb Skip Montanaro:
Couldn't you do that today in Python with a suitably sophisticated function decorator? The range/type checking would happen before the user's actual function is called.
I suppose so, but I'd have to repeat myself and it would look ugly, because I have to tell the decorator which parameter I'm talking about. Something like @do_range_check('age', 18, 100) @do_email_check('email') def register(age: int, email: str): looks not nearly as nice. Furthermore, my proposal allows multiple uses of annotations, without restricting them to a single use. If you only use mypy, you can keep using annotations as type declarations, when you use some other framework that uses annotations for a different thing, you can still use them, only once you want to use both *and* you have a method that needs both types of annotations are you forced to use the tuple notation.