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Date: Sun, 30 Jun 2013 15:08:01 +1000
Subject: Re: Closures in leu of pointers?
From: Chris Angelico <rosuav@gmail.com>
To: python-list@python.org
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On Sun, Jun 30, 2013 at 2:32 PM, Terry Reedy <tjreedy@udel.edu> wrote:
> On 6/29/2013 5:21 PM, Ian Kelly wrote:
>>
>> On Sat, Jun 29, 2013 at 2:53 PM, Terry Reedy <tjreedy@udel.edu> wrote:
>>>
>>> # The alternative for either program or people is a 1-pass + backtracking
>>> process where all understandings are kept provisional until the end of
>>> the
>>> body and revised as required. 2 passes are simpler.
>>
>>
>> Or simply an explicit declaration of scope at the beginning of the
>> function definition.
>
>
> One of the reasons I switched to Python was to not have to do that, or
> hardly ever. For valid code, an new declaration is hardly needed. Parameters
> are locals. If the first use of another name binds it (and that includes
> import, class, and def), it is local. If the first use of does not bind it,
> it had better not be local (because if it is, there well be an exception).
> If there are branches, each should be consistent with the others. One should
> only need two readings to understand and fix unbound local errors.

This is strictly a matter of opinion, and one on which mine differs
from yours. I think explicit declarations are better than implicit
"you've assigned to this name" local creations; the declarations help
to catch typos. Also, I like the consistency of C-style declarations -
where-ever you declare something, it's valid from there "in", and not
"out". Without declarations, there's a magical scope boundary at a
function definition that's different from the non-boundary at a loop,
for instance.

But that's just my opinion. and as Teresa says, I'm only one, and
possibly I'm wrong.

ChrisA