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

[Terry Reedy]

"Guido van Rossum" <guido at python.org> wrote in message
news:200403302121.i2ULLIM09840 at guido.python.org...
> > Another possibility that has been suggested is
> >
> > [decorator]
> > def func(arg, arg):
>
> And one that I currently favor.  I'm out of bandwidth to participate
> on a msg-by-msg basis, but perhaps folks can see if they can come to
> terms with this solution?

Taking the prefix position as given for the moment, why overload list
literal syntax versus something currently illegal and meaningless?  Such as

[[decorator]]      # easy enough to type, or
<decorator>      # almost as easy, or
<<decorator>>

Is there near precedent in other languages that I don't know of?

Regardless of syntax, the way I would think of the process (ie, 'come to
terms with it') is this: a string literal immediately after a function
heading automagically sets the special __doc__ attribute.  A list literal
(if that is what is used) automagically set a special __postprocess__
attribute which is read once after the body is compiled and deleted when no
longer needed.  As I understand the proposal, the actual storage would be
elsewhere in the interpreter, so the above would be 'as if'.  But, would it
be useful for later introspection to actual set and leave such an attribute
that records the decorator processing of the function?

Terry J. Reedy