Haskell Quicksort Using a Partition Helper Function

Write quicksort in Haskell by writing quickSort :: Ord a => [a] -> [a] that sorts a list, and a Partition helper function that partitions the list according to a pivot (first element).

This Implementation must be as basic as possible (~11 lines of code), no Data.List functions are allowed, and we CANNOT use the following popular implementation:

qsort [] = []

qsort (x:xs) = qsort smaller ++ [x] ++ qsort larger

where

smaller = [a | a <- xs, a <= x]

larger = [b | b <- xs, b > x]

Can somebody help? Thanks!