[Python-ideas] Deterministic iterator cleanup

[Nick Coghlan]

On 26 October 2016 at 08:48, Nathaniel Smith <njs at pobox.com> wrote:
> If it takes a strong reference, then suddenly we're pinning all
> iterators in memory until the end of the enclosing function, which
> will often look like a memory leak. I think this would break a *lot*
> more existing code than the for-scoped-iterclose proposal does, and in
> more obscure ways that are harder to detect and warn about ahead of
> time.

It would take a strong reference, which is another reason why
close_resources() would be an essential part of the explicit API
(since it would drop the references in addition to calling the
__exit__() and close() methods of the declared resources), and also
yet another reason why you've convinced me that the only implicit API
that would ever make sense is one that was scoped specifically to the
iteration process.

However, I still think the explicit-API-only suggestion is a much
better path to pursue than any implicit proposal - it will give folks
that see it for the first something to Google, and it's a general
purpose technique rather than being restricted specifically to the
cases where the resource to be managed and the iterator being iterated
over are one and the same object.

Cheers,
Nick.

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