Ben Finney <[EMAIL PROTECTED]> writes: > Evan is claiming that "the next class in the MRO _is_ a superclass", > apparently by his definition or some other that I've not seen.
The definition of superclass is not the issue, the issue is "superclass *of which class*"? You expect super(A, self) to iterate only over superclasses of A, even when self is an instance of a subtype of A. What really happens is that super(A, self) yields the next method in type(self)'s MRO, which can and does cause include classes that are not by any definition superclasses of A. All of those classes are, however, superclasses of the instance's type. I think it is not possible to have super(A, self) only call superclasses of A and at the same time having multiple inheritance work without calling some methods in the hierarchy twice or not at all. Guido's paper at http://tinyurl.com/qkjgp explains the reasoning behind super in some detail. >> I agree that the documentation for super is somewhat misleading (and >> obviously wrong), > > Well, that's the first time someone has acknowledged that in this > thread, so I guess this is something. For the record, I also agree with that. The documentation should document in some detail that super(type, obj) yields superclasses of type(obj), not of type, and that the "type" argument is only used for super to be able to locate the next type in the list. >> I wouldn't use such an extreme word as 'madness', but I totally agree >> that this should be corrected. Care to submit a doc patch ? > > I don't understand what practical uses 'super' is intended for It's intended for cooperative multiple inheritance, a la CLOS's call-next-method. -- http://mail.python.org/mailman/listinfo/python-list
