[Python-ideas] Possible PEP 380 tweak

[Greg Ewing]

Jacob Holm wrote:

> The new exception is needed because "cocall func()" can never raise the
> regular StopIteration (or any subclass thereof).

Botheration, I hadn't thought of that!

I'll have to think about this one. I still feel that it
shouldn't be necessary to define any new protocol -- one
ought to be able to simply write a __next__ cofunction that
looks like a normal one in all respects except that it's
defined with 'codef'.

Maybe a StopIteration raised inside a cofunction shouldn't
be synonymous with a return, but instead should be caught
and tunnelled around the yield-from via another exception.

-- 
Greg