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

[Phillip J. Eby]

At 09:31 PM 3/31/04 +0100, Mark Russell wrote:
>On Wed, 2004-03-31 at 20:20, Guido van Rossum wrote:
> > > I suggest that the the break-less solution
> > >
> > > [classmethod, logged, debug] def function(args):
> >
> > Sorry, can't do that with the current parser.
>
>Actually I think that's a good thing - it forces everyone to format
>things the same way.  I was a fan of the "def foo() [decorator]" syntax
>but I've changed my mind - this way has several things going for it:
>
>         - Simple implementation
>         - More or less forces one style of code layout
>         - Doesn't break tools that look for "def foo(" type patterns
>`       - Short-circuits the endless syntax discussion :-)

Um, perhaps I'm confused, but that sounds to me like a list of reasons to 
go with decorators-last.  :)

Conversely, the magic list-on-one-line, def-on-the-next is *so* implicit 
and error-prone in so many respects that it makes me want to vote against 
having decorator syntax at all.  Certainly, it's providing me with a strong 
motivation to see if I can find a way to make the current parser handle the 
"list on the same line" variation without a complete rewrite.  Perhaps a 
sneaky trick like this:

expr_stmt: testlist (augassign testlist | ('=' testlist)* | [funcdef | 
classdef] )

with a special case check that the testlist consists solely of a list, that 
triggers a syntax error at the funcdef or classdef point.