On Thu, Feb 2, 2012 at 4:34 PM, Nick Coghlan <ncogh...@gmail.com> wrote: > On Fri, Feb 3, 2012 at 10:04 AM, Guido van Rossum <gu...@python.org> wrote: >> On Thu, Feb 2, 2012 at 3:41 PM, Nick Coghlan <ncogh...@gmail.com> wrote: >>> On Fri, Feb 3, 2012 at 9:32 AM, Yury Selivanov <yselivanov...@gmail.com> >>> wrote: >>>> In my opinion using Ellipsis is just wrong. It is completely >>>> non-obvious not only to a beginner, but even to an experienced >>>> python developer. Writing 'raise Something() from None' >>>> looks less suspicious, but still strange. >>> >>> Beginners will never even see it (unless they're printing out >>> __cause__ explicitly for some unknown reason). Experienced devs can go >>> read language reference or PEP 409 for the rationale (that's one of >>> the reasons we have a PEP process). >> >> I somehow have a feeling that Yury misread the PEP (or maybe my +1) as >> saying that the syntax for suppressing the context would be "raise >> <exception> from Ellipsis". That's not the case, it's "from None". > > Oh right, that objection makes more sense. > > FWIW, I expect the implementation will *allow* "raise exc from > Ellipsis" as an odd synonym for "raise exc". I'd want to allow > "exc.__cause__ = Ellipsis" to reset an exception with a previously set > __cause__ back to the default state, at which point the synonym > follows from the semantics of "raise X from Y" as syntactic sugar for > "_exc = X; _exc.__cause__ = Y; raise _exc"
Sure. But those are all rather obscure cases. Ellipsis reads no less or more obscure than False when written explicitly. But that doesn't bother me. -- --Guido van Rossum (python.org/~guido) _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
