[Haskell-beginners] splitAt implementation (using foldr) and infinite lists

[Ozgur Akgun]

You can also use lazy pattern matching.

http://en.wikibooks.org/wiki/Haskell/Laziness#Lazy_pattern_matching

On 16 April 2012 15:21, Lorenzo Bolla <lbolla at gmail.com> wrote:

> > splitAt'    :: Int -> [a] -> ([a], [a])
> > splitAt' n  = foldr (\x ~(z1, z2) -> if fst x <= n then  (snd x : z1,
> z2)
> >                                       else              ([], snd x : z2))
> >                     ([], [])
> >                     . zip [1..]
>

Ozgur
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