[Python-ideas] Cofunctions - Back to Basics

[Nick Coghlan]

On Mon, Oct 31, 2011 at 4:54 PM, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
> Or maybe there's a third way:
>
> 3. Recognise that, today, some people *are* using generators
>   to do coroutine-like programming and finding it a useful
>   technique, despite all of its limitations, and consider
>   ways to make it easier, even if we can't remove all of
>   those limitations.
>
> It seems to me that the inability to suspend from within a
> special method is not likely to be a problem very often in
> practice.

Doing blocking I/O in special methods (other than __next__) is
generally a dubious practice anyway, so you're right that disallowing
suspension when such a function is on the stack is unlikely to be a
major problem.

> Inability to use generators as generators in a coroutine
> environment may be more serious, since it's quite likely
> people will want to e.g. use a for-loop to iterate over
> lines being read from a socket, and suspend while waiting
> for data to arrive.
>
> I think that particular problem could be solved, given
> some more thought. The question is, would it be worth the
> effort?

Yes, I think that one needs to be solved. The issue of providing
coroutine-friendly iterative builtins and itertools functionality also
need to be addressed.

Cheers,
Nick.

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