[Haskell-cafe] Re: (flawed?) benchmark : sort
ndmitchell at gmail.com
Mon Mar 10 04:36:52 EDT 2008
Can whoever picks this up please try the sort code from Yhc in their
comparisons. In my benchmarks it ran up to twice as fast as the GHC
I think what we really need is first quickCheck and timing framework
for measuring sorts. After we have decided what makes one sort
faster/better than another, then is the time to start deciding what
sort is the best one. Ian did some initial work on this:
Until the sort-check package is uploaded to hackage I think most
people will find it hard to be convinced of one sort over another.
On Mon, Mar 10, 2008 at 8:27 AM, Neil Mitchell <ndmitchell at gmail.com> wrote:
> > 2) What does it do with duplicate elements in the list? I expect it deletes
> > them. To avoid this, you'd need to use something like fromListWith, keeping
> > track of how many duplicates there are, and expanding at the end.
> That would be wrong. Consider:
> data Foo = Foo Int Int
> instance Ord Foo where
> compare (Foo a _) (Foo b _) = compare a b
> sort [Foo 1 2, Foo 1 -2] must return the original list back, in that
> order. You cannot delete things and duplicate them later. To guarantee
> the ordering you must also do other stuff.
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