On Thu, May 23, 2013 at 10:14 AM, Glenn Linderman <v+pyt...@g.nevcal.com> wrote: > Yet about half of the operator overloads would be incomplete if there were > not corresponding __r*__ methods (__radd__, __rsub__, etc.) because the > second parameter is as key to the dispatch as the first. > > While unary operators, and one argument functions would be fully covered by > single dispatch, it is clear that single dispatch doesn't cover a large > collection of useful cases for operator overloading.
The binary operators can be more accurately said to use a complicated single-dispatch dance rather than supporting native dual-dispatch. As you say, the PEP would be strengthened by pointing this out as an argument in favour of staying *away* from a multi-dispatch system (because it isn't obvious how to build a comprehensible one that would even support our existing NotImplemented based dual dispatch system for the binary operators). Cheers, Nick. -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia _______________________________________________ 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
