> Java is one language that springs to mind that uses interface
> polymorphism. Don't let this put you off -- if we must steal something
> from Java let's steal something good.
Interface inheritance is probably the least dignified thing to steal from Java.
If we have true multiple inheritance, interfaces don't apply. (As a C++
programmer, I've always had to consider the interface OOP of Java and Delphi as
flawed and incomplete. By golly, a dog CAN be a furred animal AND a four legger
without having to define one or the other entirely in each class where I want
either a furred animal and a four legger.) We already have true multiple
inheritance. Therefore, interface OOP is unnecessary. However, some syntactic
sugar to accomplish what you are looking for might be in order. Maybe
implements() or isa()? (Is a())
