Steven Bethard wrote:
> I'm having troubles coming up with things where the *basic* operator
> is really a cmp-like function.
Think of things like comparing a tuple. You need to work your
way along and recursively compare the elements. The decision
about when to stop always involves ==, whatever c
David A. Wheeler wrote:
> But mixins for comparison are a BIG LOSER for sort performance
Why not provide a __richcmp__ method that directly connects
with the corresponding type slot? All the comparisons
eventually end up there anyway, so it seems like the
right place to provide a one-stop comparis
On 10/17/07, Steven Bethard <[EMAIL PROTECTED]> wrote:
> I'm having troubles coming up with things where the *basic* operator
> is really a cmp-like function.
Here's one. When implementing the '<' operator on lists or tuples, you
really want to call the 'cmp' operator on the individual items,
beca
On Wed, Oct 17, 2007, Steven Bethard wrote:
>
> I'm having troubles coming up with things where the *basic* operator
> is really a cmp-like function. Even in your example, the cmp function
> was defined in terms of "less than". If the basic operator is really
> "less than", then why define a cmp()
On 10/17/07, David A. Wheeler <[EMAIL PROTECTED]> wrote:
> I said:
> > I agree with Collin Winter: losing __cmp__ is a loss (see
> > http://oakwinter.com/code/).
>
> Steven Bethard said:
> >Why can't this just be supplied with a mixin? Here's a recipe
> >providing the appropriate mixins if you w
On 10/17/07, David A. Wheeler <[EMAIL PROTECTED]> wrote:
> I said:
> > I agree with Collin Winter: losing __cmp__ is a loss (see
> > http://oakwinter.com/code/).
>
> Steven Bethard said:
> >Why can't this just be supplied with a mixin? Here's a recipe
> >providing the appropriate mixins if you w
On 10/17/07, David A. Wheeler <[EMAIL PROTECTED]> wrote:
> class NumberMixinCmp(ComparisonMixin):
...
> def cmp(self, other):
> if self.x == other.x: return 0
> return (-1 if self.x < other.x else 1)
In the common case the == test will be false. About ~1/2 of the
tests will b
I said:
> I did a test (see below), and the mixin using a simulated cmp took
> 50% MORE time to sort a list using Python 2.5 (see code below) than
> when __cmp__ is used directly (as you CAN do in Python 2.5).
Oops, I forgot to post the actual numbers. Here they are, on my box (your
mileage will
I said:
> I agree with Collin Winter: losing __cmp__ is a loss (see
> http://oakwinter.com/code/).
Steven Bethard said:
>Why can't this just be supplied with a mixin? Here's a recipe
>providing the appropriate mixins if you want to define a __key__
>function:
>http://aspn.activestate.com/AS
