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

Marek "Baczek" Baczyński imbaczek at gmail.com
Wed Jul 5 12:17:16 CEST 2006

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.

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

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