> I think it would also be great if we had "ability > algebra" whereby you could state that a given ability A is composed of > existing abilities A1 and A2, and every object or class that already > has A1 and A2 will automatically be considered to have A.
Yes! > However, I do *not* want to go the way of duck typing here -- if an > ability A claims that it is implemented by method foo(), and an object > x has a foo() method but doesn't explicitly claim to have ability A > (and neither does its class), then testing x for A should return > false. Also yes. > I think this deviates from Haskell, which seems to be big on > structural type equivalence (?). How so? > So I think Python needs to do its own thing here, to some extent. Yup. That's part of why I like the term "ability" -- one isn't tempted to think it means the same thing as the corresponding term in another language. _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
