[Python-3000] optimizing [x]range

["Martin v. Löwis"]

>> Don't forget the *cost* in terms of code bloat. Plus, I asked for a
>> patch. Where is it? This is not Santa Claus's email address. You're
>> expected to contribute more than a wish.
> 
> first off all, that's not the politest way to put it, especially since i have
> submitted some patches before. second, i've already given a 3-line
> implementation in python. it would only take two minutes to convert
> it to C, save the unit tests. third, i'm busy over my head studying of
> my exams. forth, due to lack of public interest, i might as well
> withdraw this.

It's not that *you* were asked to contribute it. Guido just pointed
out that, without a patch, it won't get implemented. More so if
the patch is as trivial as you expect it to be. We *all* are
under time pressure - I am busy giving exams, for example.

So to your original question "why not optimize it?", there is
a very simple answer: there is no ready implementation available.

> besides, that's not the point. i'm only saying there's no reason that
> testing for containment in range objects (which are no longer lists),
> should be O(N), when it can easily be made O(1) in under 10 lines of C
> code.

Nothing is easy. Neal Norwitz was working on implementing xrange with
longs, and it took an entire week. The patch is still sitting on SF
somewhere.

Regards,
Martin