[Python-Dev] Re: anonymous blocks

Tim Delaney tcdelaney at optusnet.com.au
Thu Apr 28 01:07:00 CEST 2005

Guido van Rossum wrote:

>> A minor sticking point - I don't like that the generator has to
>> re-raise any ``StopIteration`` passed in. Would it be possible to
>> have the semantics be: 
>>     If a generator is resumed with ``StopIteration``, the exception
>>     is raised at the resumption point (and stored for later use).
>>     When the generator exits normally (i.e. ``return`` or falls off
>>     the end) it re-raises the stored exception (if any) or raises a
>> new ``StopIteration`` exception. 
> I don't like the idea of storing exceptions. Let's just say that we
> don't care whether it re-raises the very same StopIteration exception
> that was passed in or a different one -- it's all moot anyway because
> the StopIteration instance is thrown away by the caller of next().

OK - so what is the point of the sentence::

    The generator should re-raise this exception; it should not yield
    another value.  

when discussing StopIteration?

Tim Delaney

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