[Python-3000] Traits/roles instead of ABCs

[Paul Moore]

On 30/04/07, Bill Janssen <janssen at parc.com> wrote:
> > 6) that doesn't freeze all of the key APIs in concrete
>
> After 15 years of experience with the key APIs, we could perhaps freeze some of
> them?

After 15 years not being able to clearly state what "file-like" or
"mapping-like" means to different people, perhaps we should accept
that there is no clear-cut answer...?

> In other words, what APIs does this value support?
> In other words, what APIs does this value support?
> In other words, what APIs does this value support?

Yes, but the ABC proposal is about establishing a vocabulary for
answering those questions, not about asking them. It's not at all
clear (to me, at least) that there is agreement that the vocabulary
proposed is helpful.

> If we simply had a small standard extensible set of APIs, and a way to
> indicate that a value does or doesn't support one or more of them,
> we'd be done.  We could either add a new mechanism to do this, or simply
> actually use the one we already have, which should work perfectly well for
> this purpose.

And which has been around for many years, but has never actually been
used in practice (unlike, say, interfaces). Does this not say
something?

Paul.