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

[Marek "Baczek" Baczyński]

2006/7/5, Just van Rossum <just at letterror.com>:
> 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*.

<delurk>

I suggest <- as an assignment operator instead of := - it's used in
OCaml and it looks *very* different, yet still makes sense.

  x = 0
  print x
  def f():
    x =  1 # bind locally
    print x
  def g():
    x <- 42 # assign "lexically"
    print x
  f()
  print x
  g()
  print x

prints

0
1
0
42
42

</delurk>