[Python-Dev] accumulator display syntax
Samuele Pedroni
pedronis at bluewin.ch
Tue Oct 21 18:49:23 EDT 2003
At 00:43 22.10.2003 +0200, Samuele Pedroni wrote:
>this is a bit OT and too late, but given that our closed over variables
>are read-only, I'm wondering whether, having a 2nd chance, using cells and
>following mutations in the enclosing scopes is really worth it, we kind of
>mimic Scheme and relatives but there outer scope variables are also
>rebindable. Maybe copying semantics not using cells for our closures would
>not be too insane, and people would not be burnt by trying things like this:
>>for msg in msgs:
> def onClick(e):
> print msg
> panel.append(Button(msg,onClick=onClick))
>>which obviously doesn't do what one could expect today. OTOH as for
>general mutability, using a mutable object (list,...) would allow for
>mutability when one really need it (rarely).
of course OTOH cells make it easier to cope with recursive references:
def g():
def f(x):
... f refers to f ...
return f
but this seem more an implementation detail, although not using cells would
make this rather
trickier to support.
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