Bengt Richter wrote:
>
> It might be interesting to have a means to push and pop objects
> onto/off-of a name-space-shadowing stack (__nsstack__), such that the first
> place
> to look up a bare name would be as an attribute of the top stack object, i.e.,
>
> name = name + 1
>
Don't be that specific; just unify Attributes and Names.
Instead of the 'name' X referring to locals()['X'] or globals()['X'],
have a hidden "namespace" object/"class", with lookups functioning akin
to class inheritence.
This would allow, in theory, more uniform namespace behaviour with outer
scoping:
x = 1
def f():
x += 1 # would work, as it becomes
setattr(namespace,'x',getattr(namespace,'x')+1), just like attribute loookup
Also, with a new keyword "outer", more rational closures would work:
def makeincr(start=0):
i = start
def inc():
outer i
j = i
i += 1
return j
return inc
From a "namespace object" point of view, 'outer i' would declare i to
be a descriptor on the namespace object, such that setting actions would
set the variable in the inherited scope (getting actions wouldn't
actually need modification, since it already falls-through). At the
first level, 'outer' would be exactly the same as 'global' -- indeed, it
would be reasonable for the outer keyword to entirely replace global
(which is actually module-scope).
As it stands, the different behaviours of names and attributes is only a
minor quirk, and the fix would definitely break backwards compatibility
in the language -- it'd have to be punted to Py3k.
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