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

[Jeremy Hylton]

On 7/10/06, Ka-Ping Yee <python-dev at zesty.ca> wrote:
> On 7/10/06, Ka-Ping Yee <python-dev at zesty.ca> wrote:
> > What's wrong with "nonlocal"?  I don't think i've seen an argument
> > against that one so far (from Talin or others).
>
> On Mon, 10 Jul 2006, Jeremy Hylton wrote:
> > It's a made-up word.  You won't find it in the dictionary and the
> > google define: query sends me to a wikipedia page about quantum
> > mechanics.
>
> Two million Google hits for "nonlocal" seems like plenty.
> The explanation of "nonlocal" is pretty straightforward --
>
>     If the definition of f() contains an assignment to x, then
>     x is a local variable in f, unless x is declared nonlocal.
>
> > To express this email in the positive form:
> > 1. Reserved words should be real words.
> > 2. The meaning of the word should be clear.
> > 3. "Put statements in positive form."  (Strunk & White)
> > 4. The word should sound good.
> >
> > global meets all of these requirements.
>
> But it's the wrong word.  "Purple" also meets all of these requirements.

No.  Don't be silly.

The current use of global meets the requirements.  The meaning there
is clear, because global means global namespace.  If purple were a
keyword, I wouldn't know what it means.  I was not proposing the use
of global for some other meaning (and thought I made that clear in the
remainder of the message).

Jeremy

>
> I'd rather accurately express the concept in the negative (the
> true meaning really is in the negative: "don't make a new binding"),
> than choose a simple-sounding word that is essentially a lie.
>
>     x = 1
>
>     def f(x):
>         print x
>
>         def g():
>             global x
>             x = 3
>             print x
>
> The "x" used in g is not global at all -- it belongs to f.
>
>
> -- ?!ng
>