Andreas Rossberg schrieb: > Chris Uppal wrote: > >> It's worth noting, too, that (in some sense) the type of an object can >> change over time[*]. > > No. Since a type expresses invariants, this is precisely what may *not* > happen.
No. A type is a set of allowable values, allowable operations, and constraints on the operations (which are often called "invariants" but they are invariant only as long as the type is invariant). I very much agree that the association of a type with a value or a name should be constant over their lifetime - but that doesn't follow from the definition of "type", it follows from general maintainability considerations (quite strong ones actually). Regards, Jo -- http://mail.python.org/mailman/listinfo/python-list
