At 09:11 PM 1/3/2007 -0800, Guido van Rossum wrote:
>On 1/3/07, Phillip J. Eby <[EMAIL PROTECTED]> wrote:
>>Or perhaps translate blocks of the form:
>>
>> except ExcType, e:
>> # body
>>
>>to:
>>
>> except ExcType, e:
>> try:
>> # body
>> finally:
>> del e
>>
>>This won't stop you from creating a cycle explicitly, of course, but it
>>would ensure that the simple cases would be cycle-free.
>
>+1!
>
>I used to dislike this because there are use cases for letting the
>exception survive the except clause, but I think I can get used to it,
>and it seems the most straightforward solution of all that I've seen.
>We could completely get rid of sys.exc_info()! I think we have a
>winner here.
Actually, on second thought it occurs to me that the above code isn't a
100% correct translation, because if "body" contains its own "del e", then
it will fail. So a pure translation strategy isn't really practical,
unfortunately. We'd have to generate something like:
if 'e' in locals():
del e
or add a new bytecode that's equivalent to that.
>Explicitly created cycles are no big deal IMO -- these are no worse
>than current code that explicitly stores sys.exc_info()[2].
True, but now they get that overhead simply by storing the exception
object. On the other hand, I suppose code that might store a lot of
exception objects will just have to be careful to clear tracebacks it
doesn't need.
_______________________________________________
Python-3000 mailing list
Python-3000@python.org
http://mail.python.org/mailman/listinfo/python-3000
Unsubscribe:
http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
