[Python-ideas] Revised**10 PEP on Yield-From

[Nick Coghlan]

Jacob Holm wrote:
>    * The "what should close() do if it catches StopIteration with a
>      value" issue I don't think we have resolved either way.  Since we
>      are not going to store the value, only the first close() would be
>      able to return it.  Under those conditions, I no longer think that
>      returning the value is a good idea.  If we are not storing or
>      returning the value, I think close() should raise an exception.
>      Either reraise the StopIteration, so that the caller has a chance
>      to get the value that way, or raise a RuntimeError, because it is
>      meaningless to return a value as response to a GeneratorExit when
>      that value cannot later be accessed by anything and it is
>      therefore most likely a bug.

If you care about a generator's return value *don't* just call "close()"
on it. Use "throw(GeneratorExit)" instead so you can catch the exception
and interrogate the return value yourself.

Cheers,
Nick.

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