the quick sort definition has something wrong

[Hobinx]

The definition forgot to recursively call itself, and the order of the predicates should be swapped, may be:

quicksort : List comparable -> List comparable
quicksort list =
  case list of
    [] -> []
    (x::xs) -> 
      let 
        smallerSorted = quicksort (List.filter ((>) x) xs)
        biggerSorted = quicksort (List.filter ((<=) x) xs)
      in
        smallerSorted ++ [x] ++ biggerSorted

[deadfoxygrandpa]

Thanks, you're right. Your definition works.

[Hobinx]

Thanks, glad to hear that.