On 11/13/06, Guido van Rossum <[EMAIL PROTECTED]> wrote: > On 11/13/06, George Sakkis <[EMAIL PROTECTED]> wrote: > > On 11/13/06, Guido van Rossum <[EMAIL PROTECTED]> wrote: > > > > > As my final word, I think this is a seriously bad idea, and as you're > > > not answering my challenge about duck typing I don't think you > > > understand your own proposal. > > > > I think I do, though I can't tell the same about the reasons of your > > objections to it. In your previous reply you mentioned that I need to > > have a more technical argument to convince you, and that's why I chose > > to reply with the most technical argument, a proof of concept > > implementation that addresses your concerns about how to incorporate > > the itertools functions as methods. > > > > As for the duck typing, I mentioned already that nobody forces you to > > extend this type to make some class an iterator, as nobody forces you > > to extend dict or dictmixin to write a user-defined mapping. You may > > well start from scratch implementing just next(); if you don't plan to > > use "+", "*" or any of the itertools operations on this type, > > extending Iter is useless. If you do plan to provide these operations > > though, you may either write them from scratch every time, or extend > > Iter. > > > > I honestly fail to understand your current objections. Is my analogy > > with dictmixin flawed ? Would anything change if I named it > > "itermixin" instead of iter or Iter ? I'm ok with the idea being > > rejected, but at least I'd like to understand the reasons. > > The flaw is that you're creating two categories of iterators: those > that support the various methods you're adding, and those that don't. > This means that the itertools module can't be discarded, because it is > still needed to support those operations for the iterators that don't > have them natively. Thus, you're introducing two ways of doing the > same thing -- using itertools (works for all iterators) or using the > methods (only works for iterators that inherit from your base class).
Understood. Any _technical_ reasons then why shouldn't all iterators inherit from it, or "duck typing is The Right Way" should be taken as axiom ? Why do we somehow _need_ itertools when we don't need sequencetools, mappingtools, etc ? What's special about the iterator protocol ? George _______________________________________________ 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
