Dec. 3, 2003
4:10 p.m.
It's not me, it's Barbara Liskov at MIT.
:-) (For non-OO wizards, this is called "Liskov substitutability".)
The general notion is that if Y is derived from X, then you should be able to use a Y wherever you might otherwise want to use an X. In other words, Y should support every operation that X supports, but Y can add operations of its own.
So the question is, does long have operations that int doesn't have? And if so, why can't those operations be added to int? And if there's a reason, is it good enough? If the sets of operations are identical, is there a way to break the tie? --Guido van Rossum (home page: http://www.python.org/~guido/)