[Python-Dev] Re: PEP 318: Decorators last before colon

[Casey Duncan]

On Thu, 01 Apr 2004 17:25:20 -0500
David Abrahams <dave at boost-consulting.com> wrote:

> Jeremy Hylton <jeremy at alum.mit.edu> writes:
> 
> > On Thu, 2004-04-01 at 07:13, Michael Hudson wrote:
> >> > I don't think Michel is saying they are worthless.  However, the
> >> > proposed syntax is highly contentious.  It would be good if there
> >> > was a short term solution that wouldn't require new syntax.  That
> >> > would give Guido and the Python community time to figure out the
> >> > best syntax.
> >> 
> >> We've been discussing this off and on for OVER A YEAR!  If 'the
> >best> syntax' hasn't been figured out yet after N thousand emails on
> >the> subject, I see no reason to believe enlightenment is going to
> >arrive> soon (or ever).
> >
> > There's no particular reason to believe that effort alone will
> > arrive at an elegant solution.  On the other hand, maybe there isn't
> > a good syntax for arbitrary decorators.
> 
> Has something along these lines been discussed?
> 
>   with [staticmethod, classmethod]:
> 
>      def foo(x):
>          pass
> 
>      def bar(x):
>          pass
> 
> IIUC, the PyObjC application needs whole swathes of functions with
> the same decoration, but this syntax isn't much worse for one
> function than for many.

What if you dropped the keyword?

  [classmethod]:

      def splat(cls):
          pass

      def baz(cls):
          pass

Or how about as?

  as classmethod:

     def jinkies(cls):
         pass

Which seems nice in the face of other declarations:

  as protected(some_permission):

     def zoinks(self, scooby, snack):
         pass

     def jinkies(self):
         pass

or

  [protected_by(some_permission)]:

      def dangerous(self, risk):
          pass

At least then the ambiguity is gone wrt unassigned lists before defs
(and I won't have to rewrite all that code where I'm using list
comprehensions as docs before method defs ;^). Also the grouping seems
useful.

OTOH, madatory bracketing seems unpythonic to me, which makes as/with
option (without mandatory brackets) seem compelling.

-Casey