Quicksort in different languages

quicksort.hs

import Data.List
import Control.Monad
import Control.Arrow

qsort :: (a -> a -> Bool) -> [a] -> [a]
qsort _ [] = []
qsort comp (x:xs) = smaller ++ [x] ++ bigger
    where (smaller, bigger) = join (***) (qsort comp) $ comp x `partition` xs

main :: IO ()
main = do
  let foo = [2, 1, 2, 3]
  print $ qsort (>) foo