On 12 October 2016 at 21:35, Paul Moore <p.f.mo...@gmail.com> wrote: > What I'm *not* quite clear on is why Python 3's change to reject > comparisons between unrelated types makes this optimisation possible. > Surely you have to check either way? It's not that it's a particularly > important question - if the optimisation works, it's not that big a > deal what triggered the insight. It's just that I'm not sure if > there's some other point that I've not properly understood.
It's probably more relevant that cmp() went away, since that simplified the comparison logic to just PyObject_RichCompareBool, without the custom comparison function path. It *might* have still been possible to do something like this in the Py2 code (since the main requirement is to do the pre-check for consistent types if the first object is of a known type with an optimised fast path), but I don't know anyone that actually *likes* adding new special cases to already complex code and trying to figure out how to test whether or not they've broken anything :) Cheers, Nick. -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
