Please, I don’t understand where is the erro in the code below.
quicksort :: Ord a => [a] -> [a]
quicksort [] = []
quicksort (s:xs) = quicksort [x|x <- xs,x < s] ++ [s] ++ quicksort [x|x <- xs,x >= s]
main :: IO ()
main = do
xs::Array Int Int xs = array (1,9) [(1,9),(1,1),(2,8),(3,2),(4,5),(6,7),(7,3),(8,6),(9,4)]