Comparing functions in Haskell

Question

Is there any way to compare two functions in Haskell?

My thought is that the answer is no since functions would not derive the Eq type class. However I\'m trying to

Answer 1

The code below may not compile, but hopefully you get the idea:

data Op = Succ | Pred deriving Eq

fromOp :: Enum a => Op -> a -> a
fromOp Succ = succ
fromOp Pred = pred

search :: Op -> Card -> [Card] -> [Card]
search op x list = if (op == Succ && rank x == King) || 
                      (op == Pred && rank x == Ace)
                   then []
                   else let c = [ n | n <- list, rank n == (fromOp op) (rank x)]
                     in if length c == 1
                     then x : search op (head c) list
                     else []