Переделать быструю сортировку

thirdElem (_,_,c) = c
 
qsort [] = []
qsort (h:t) = 
    qsort[x|x<-t, x<=h]++[h]++qsort[x|x<-t,x>h]

thirdElem :: Ord a => (b,c,a) -> a
thirdElem (_,_,c) = c
 
qsort :: Ord a => [(b,c,a)] -> [(b,c,a)]
qsort [] = []
qsort (h:t) = 
    let third = thirdElem h in
    qsort[x|x<-t, thirdElem x <= third]++[h]++qsort[x|x<-t, thirdElem x > third]

thirdElem :: Ord a => (b,c,a) -> a
thirdElem (_,_,c) = c
 
qsortF :: Ord a => (b -> a) -> [b] -> [b]
qsortF _ [] = []
qsortF f (h:t) = 
    let hv = f h in
    qsortF f [x|x<-t, f x <= hv] ++ [h] ++ qsortF f [x|x<-t, f x > hv]
 
qsort :: Ord a => [(b,c,a)] -> [(b,c,a)]
qsort = qsortF thirdElem

qsort [] = []
qsort (h:t) = 
    qsort [x | x <- t, x <= h] ++ [h] ++ qsort [x | x <- t, x > h]
 
data Foo = Foo (Char, Char, Int) deriving (Eq, Show)
 
data Bar = Bar {
    ch1 :: Char,
    ch2 :: Char,
    ord :: Int
} deriving (Eq, Show)
 
instance Ord Foo where
    compare (Foo (_, _, x)) (Foo (_, _, y)) = compare x y
 
instance Ord Bar where
    compare (Bar _ _ x) (Bar _ _ y) = compare x y
 
testDataFoo = [Foo ('d', 'k', 21), Foo ('a', 'b', 1), Foo ('x', 'y', 34)]
testDataBar = [Bar 'd' 'k' 21, Bar 'a' 'b' 1, Bar 'x' 'y' 34]
 
main = do
    print $ qsort testDataFoo
    print $ qsort testDataBar

thirdElem :: Ord a => (b,c,a) -> a
thirdElem (_,_,c) = c
 
qsort :: Ord a => [(b,c,a)] -> [(b,c,a)]
qsort [] = []
qsort (h:t) = 
    let third = thirdElem h in
    qsort[x|x<-t, thirdElem x <= third]++[h]++qsort[x|x<-t, thirdElem x > third]

class Eq a => Ord a where
  compare :: a -> a -> Ordering
  (<) :: a -> a -> Bool
  (<=) :: a -> a -> Bool
  (>) :: a -> a -> Bool
  (>=) :: a -> a -> Bool
  max :: a -> a -> a
  min :: a -> a -> a

class Eq a where
  (==) :: a -> a -> Bool
  (/=) :: a -> a -> Bool

qsort :: Ord a => [(b,c,a)] -> [(b,c,a)]