[Python-3000] Builtin iterator type

[George Sakkis]

On 11/13/06, Guido van Rossum <guido at python.org> 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.

George