On Thu, Jun 24, 2010 at 1:12 AM, Stephen J. Turnbull <step...@xemacs.org> wrote: > Guido van Rossum writes: > > > For example: how we can make the suite of functions used for URL > > processing more polymorphic, so that each developer can choose for > > herself how URLs need to be treated in her application. > > While you have come down on the side of polymorphism (as opposed to > separate functions), I'm a little nervous about it. Specifically, > Philip Eby expressed a desire for earlier type errors, while > polymorphism seems to ensure that you'll need to Look Before You Leap > to get early error detection.
Understood, but both the majority of str/bytes methods and several existing APIs (e.g. many in the os module, like os.listdir()) do it this way. Also, IMO a polymorphic function should *not* accept *mixed* bytes/text input -- join('x', b'y') should be rejected. But join('x', 'y') -> 'x/y' and join(b'x', b'y') -> b'x/y' make sense to me. So, actually, I *don't* understand what you mean by needing LBYL. -- --Guido van Rossum (python.org/~guido) _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com