On 5/20/06, Steven Bethard <[EMAIL PROTECTED]> wrote: > On 5/20/06, Guido van Rossum <[EMAIL PROTECTED]> wrote: > > I've already addressed Steve's other issues. The blogs have the use cases > > etc. > > I'm sorry, I guess I'm just dense, but here's the blogs I've read: > > http://www.artima.com/weblogs/viewpost.jsp?thread=85551 > http://www.artima.com/weblogs/viewpost.jsp?thread=86641 > http://www.artima.com/weblogs/viewpost.jsp?thread=87182 > http://www.artima.com/weblogs/viewpost.jsp?thread=89161 > http://www.artima.com/weblogs/viewpost.jsp?thread=101605 > http://www.artima.com/weblogs/viewpost.jsp?thread=92662 > http://www.artima.com/weblogs/viewpost.jsp?thread=155123 > > And the only use-cases I could extract are: > > * optional type checking. Lots of thoughts here, and it seemed like > most of the blogs were leaning towards introducing interfaces to avoid > requiring concrete types. But the discussion here has been using > things like 'int' and 'str', so I'm confused as to whether or not this > is still the intention.
This was mostly retracted later. Re-read this one: http://www.artima.com/weblogs/viewpost.jsp?thread=86641 especially the section on Motivation. > * function overloading[1]. I think Philip J. Eby had some interesting > thoughts here, but in all the prototypes, dispatching was done on > concrete types. Is there a way to do function overloading that > doesn't rule-out duck typing and is still reasonably efficient? You may have read my prototypes, which dispatch on concrete types. Phillip lets you dispatch on predicates like hasattr(x, 'append'). > I guess, in general, my concerns about the use-cases I found were that: > > (1) there were very few real implementations of the ideas, and Collin Winters is pretty real, and I believe one other person (Tony Lownds?) has another. > (2) where there was an implementation, it relied on concrete types Collin's doesn't. (He rewrote his tutorial to remove this.) > Is it the intention that type annotations be used primarily to check > concrete types? To the contrary, that would be a big mistake. > Or maybe interfaces are being introduced so that type > annotations can check them instead? If so, I'd like to see one of the > prototype systems using interfaces. Or maybe there's some other way > that type annotations are going to be used that doesn't rely on > concrete types that I've just missed? > > Sorry to still not be getting it! You could build your own system using interfaces, perhaps by combining Zope/Twisted interfaces with Collin's implementation? -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ Python-3000 mailing list [email protected] http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
