> On 22 Jul 2015, at 19:12, Steve Dower <steve.do...@microsoft.com> wrote: > > Terry Reedy wrote: >> On 7/22/2015 3:25 AM, Ronald Oussoren wrote: >>> Hi, >>> >>> Another summer with another EuroPython, which means its time again to >>> try to revive PEP 447… >>> >>> I’ve just pushes a minor update to the PEP and would like to get some >>> feedback on this, arguably fairly esoteric, PEP. >> >> Yeh, a bit too esoteric for most of us to review. For instance, it is not >> obvious to me, not familiar with internal details, after reading the intro, >> why >> a custom __getattribute__ is not enough and why __getdescriptor__ would be >> needed. If Guido does not want to review this, you need to find a PEP BDFL >> for >> this. >> >> There are two fairly obvious non-esoteric questions: >> >> 1. How does this impact speed (updated section needed)? > > Agreed, this is important. But hopefully it's just a C indirection (or better > yet, a null check) for objects that don't override __getdescriptor__.
Not a null check, but a check for a specific function pointer. That way you can be sure that super classes always have the slot which IMHO gives a nicer user experience. > >> 2. Is this useful, that you can think of, for anything other than connecting >> to >> Objective C? > > There are other object models that would benefit from this, but I don't > recall that we came up with uses other than "helps proxy to objects where > listing all members eagerly is expensive and/or potentially incorrect". Maybe > once you list all the operating systems that are now using dynamic > object-oriented APIs rather than flat APIs (Windows, iOS, Android, ... > others?) this is good enough? > > FWIW, I'm still +1 on this, pending performance testing. The PEP on the website contains performance test data, but that’s out of data. I don’t think the implementation of attribute lookup has changed enough to really invalidate those test results, but I will rerun the tests once I’ve updated the patch because hunches don’t count when evaluating performance. Ronald > > Cheers, > Steve > >> -- >> Terry Jan Reedy > > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org <mailto:Python-Dev@python.org> > https://mail.python.org/mailman/listinfo/python-dev > <https://mail.python.org/mailman/listinfo/python-dev> > Unsubscribe: > https://mail.python.org/mailman/options/python-dev/ronaldoussoren%40mac.com > <https://mail.python.org/mailman/options/python-dev/ronaldoussoren%40mac.com>
_______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
