[Python-3000] Function annotations considered obfuscatory (Re: Conventions for annotation consumers)

[Guido van Rossum]

On 8/15/06, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
> Collin Winter wrote:
>
> > @docstring
> > @typechecker
> > @constrain_values
> > def foo(a: {'doc': "Frobnication count",
> >            'type': Number,
> >            'constrain_values': range(3, 9)},
> >        b: {'type': Number,
> >             # This can be only 4, 8 or 12
> >            'constrain_values': [4, 8, 12]}) -> {'type': Number}
>
> There's another thing that's bothering me about all this.
> The main reason Guido rejected the originally suggested
> syntax for function decorators was that it put too much
> stuff into the function header and obscured the signature.
>
> Now we seem to be about to open ourselves up to the
> same problem on an even bigger scale. Who can honestly
> say that the above function declaration is easy to read?
> To me it looks downright ugly.

It's a worse-case scenario suggesting how one could solve a very hairy
problem. I don't expect that something this extreme will be at all
common (otherwise I'd be against it too).

PS. http://meyerweb.com/eric/comment/chech.html

-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)