[Python-Dev] type categories

[Guido van Rossum]

> A few weeks ago I realized there was reason in principle that
                                   ^^^^^^^^^^
Did you mean "was no reason"???

> declaring a class satisfies an interface shouldn't just amount to
> adding the interface to the class' __bases__ (as Guido has been
> suggesting all along).
> 
> Why not? Am we missing somethings?

We'd need a trick to deny an interface that would be inherited by
default.  Something like private inheritance.

There's also the ambiguity of inheriting from a single interface: does
that create a sub-interface or an implementation of the interface?
Of course with your C++ hat on you probably don't care.  On Mondays,
Wednesdays, Fridays and alternating Sundays I don't care either.

--Guido van Rossum (home page: http://www.python.org/~guido/)