[Python-Dev] uthread strawman
Thu, 09 Nov 2000 15:26:17 +0200
Moshe Zadka wrote:
> On Thu, 9 Nov 2000, Christian Tismer wrote:
> > Does anybody know of a useful example where continuations
> > are really needed?
> Well, it may be a bit unpythonic (for several reasons), but restartable
> exceptions AFAICS cannot be implemented by generators or coroutines.
> Restartable exceptions are not always appropriate, but tend to be
> a pain to simulate when they are needed.
(sorry for posting to python-dev/null but Starship is still down)
How would restartable exceptions work? Like so?
try: # here, a continuation is saved
pass # some operations which may fail,
# raising something that inherits from RestartableException
pass # repair the condition
sys.try_again() # go back to the try statement
Probably not, since this would be doable by just an internal
But if the restartable exception were a callable object,
continuations might be necessary, since we now have a fork
of two concurrently existing execution paths in the frame:
We might continue with the exception handling but pass the
restartable to someone else, who tries to call it later.
cheers - chris
Christian Tismer :^) <mailto:email@example.com>
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