[Python-ideas] Yield-From: GeneratorReturn exception

[Guido van Rossum]

On Sat, Mar 28, 2009 at 8:00 PM, Nick Coghlan <ncoghlan at gmail.com> wrote:
> Greg Ewing wrote:
>> While attempting to update the PEP to incorporate a
>> GeneratorReturn exception, I've thought of a potential
>> difficulty in making the exception type depend on
>> whether the return statement had a value.
>>
>> Currently the StopIteration exception is created after
>> the return statement has unwound the stack frame, by
>> which time we've lost track of whether it had an
>> expression.
>
> Does it become easier if "return None" raises StopIteration instead of
> raising GeneratorReturn(None)?
>
> I think I'd prefer that to having to perform major surgery on the eval
> loop to make it do something else... (Guido may have other ideas,
> obviously).

I think my first response on this (yesterday?) already mentioned that
I didn't mind so much whether "return None" was treated more like
"return" or more like "return <value>". So please do whatever can be
implemented easily.

-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)