[Python-3000] Abilities / Interfaces

[Guido van Rossum]

On 11/22/06, Phillip J. Eby <pje at telecommunity.com> wrote:
> In other words, this isn't some sort of moral judgment regarding the
> "purity" of interfaces or inspection, it's merely a comment about how best
> to *construct* them.  Building interfaces in the Java/Zope style (as mere
> collections of method names) loses you things that you can't just put back
> in later.

I'm not sure that it's right to describe Java/Zope interfaces as "mere
collections of method names". For example, Java's collections
framework (http://java.sun.com/j2se/1.4.2/docs/guide/collections/)
ascribes a lot of semantics to its interfaces that aren't expressible
by method signatures alone, and strongly urges implementations to
implement the right semantics (of course some folks cheat, but that
doesn't invalidate the point).

So maybe there are even less differences between the different POVs.

I'm not arguing that generics aren't strictly more powerful than
interfaces -- I just think that interfaces don't necessarily deserve
the bad rep you're creating for them, and I'd like to have interfaces
prominently in Py3k's toolbox (as well as generics) rather than having
to hide them in the closet.

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