[Python-Dev] Explicit Lexical Scoping (pre-PEP?)

[Guido van Rossum]

On 7/5/06, Just van Rossum <just at letterror.com> wrote:
> Guido van Rossum wrote:
>
> > On 7/5/06, Phillip J. Eby <pje at telecommunity.com> wrote:
> > > Did you also consider and reject:
> > >
> > > * Alternate binding operators (e.g. ":=", ".=", etc.)
> >
> > Brr.
>
> That's too bad :(
>
> I still find a rebinding operator (":=" being my favorite) much, *much*
> more appealing than any of the alternative proposals. It's beautifully
> symmetrical with "assignment means local". It also pretty much makes the
> global statement redundant.
>
> The only downside I see is that it may cause a fairly big shift in
> style: I for one would use := for rebinding local names. While I think
> that would be an improvement (eg. by catching typo's earlier), it's
> *different*.

Hallo broer! :-)

I wonder what this should mean then:

def outer():
  def inner():
    x := 1

What is x's scope?

Also, a := operator allows all sorts of left-hand sides that don't
necessarily make sense, e.g.

x.foo := 1
x[0] := 1

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