[Haskell-cafe] Time consumption nub

[Arie Groeneveld]

I tried this version,
> however....
>>> nsortBy cmp l = mergesort compare l
> should be:
>
> nsortBy cmp l = mergesort cmp l
>
> Thanks
Sorry, with this version I meant:

> nsort l = mergesort compare l
> nsortBy cmp l = mergesort compare l
>
> mergesort :: (a -> a -> Ordering) -> [a] -> [a]
> mergesort cmp = mergesort' cmp . map wrap
>
> mergesort' :: (a -> a -> Ordering) -> [[a]] -> [a]
> mergesort' cmp [] = []
> mergesort' cmp [xs] = xs
> mergesort' cmp xss = mergesort' cmp (merge_pairs cmp xss)
>
> merge_pairs :: (a -> a -> Ordering) -> [[a]] -> [[a]]
> merge_pairs cmp [] = []
> merge_pairs cmp [xs] = [xs]
> merge_pairs cmp (xs:ys:xss) = merge cmp xs ys : merge_pairs cmp xss
>
> merge :: (a -> a -> Ordering) -> [a] -> [a] -> [a]
> merge cmp xs [] = xs
> merge cmp [] ys = ys
> merge cmp (x:xs) (y:ys)
>  = case x `cmp` y of
>         GT -> y : merge cmp (x:xs)   ys
>         LT -> x : merge cmp    xs (y:ys)
>         EQ -> x : merge cmp    xs    ys
>
> wrap :: a -> [a]
> wrap x = [x]
>