[Python-ideas] Tweaking closures and lexical scoping to include the function being defined

[Nick Coghlan]

On Thu, Sep 29, 2011 at 9:07 PM, Ron Adam <ron3200 at gmail.com> wrote:
> On Thu, 2011-09-29 at 13:01 -0700, Guido van Rossum wrote:
>> On Thu, Sep 29, 2011 at 12:03 PM, Eric Snow <ericsnowcurrently at gmail.com> wrote:
>> > The alternative is to leave nonlocal as just a simple statement, but
>> > change its behavior when the name is not found inside a containing
>> > function scope.  Currently that is a syntax error.
>>
>> For a reason. It would be too easy for a typo to produce the wrong
>> interpretation.
>
> But this is exactly how it works now!  The behavior of nonlocal doesn't
> need to be changed.  It already behaves that way with closures. :-)

That isn't what Guido and Eric are talking about here. They're talking
about this syntax error:

>>> def f():
...     nonlocal x
...
SyntaxError: no binding for nonlocal 'x' found

We had the opportunity in PEP 3104 to make 'nonlocal x' a synonym for
'global x' and chose not to do so. After deliberately passing up that
more obvious interpretation, we aren't likely to now decide to use it
to denote function state variables.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia