At 04:06 PM 11/21/2006 -0800, Guido van Rossum wrote: >On 11/21/06, Nestor <[EMAIL PROTECTED]> wrote: > > Do these aproaches allow to do something like the > > java.util.RandomAccess interface that is just used as a marker? > >Zope interfaces certainly do. I don't know about Phillip's >counter-proposal.
If we're basing GF's on types, then certainly marker mixins are feasible to *use*. I only contend that mixin markers (and other pure interfaces devoid of execution effect) are unnecessary and shouldn't be encouraged, not that they are or should be impossible. > With ABCs it would seem that one has to plan this >ahead of time (i.e., at class definition time), which isn't always >reasonable. For this reason, I would be against allowing *only* definition-time interface declarations. A major benefit of both adaptation and generic functions is that they allow retrofitting or gluing of "oblivious" code; i.e., code that wasn't originally designed to work with the thing you're gluing it to. Having only interfaces and introspection would also just mean that we are adding Java-like declarations and LBYLisms, without any improvements in expressive power or code clarity. Declaring an interface or adding a mixin should *do* something, instead of simply being a comment in the form of code, that other code is able to read. :) _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
