[Haskell-beginners] Help with "20 intermediate haskell exercises"

[Patrick LeBoutillier]

Hi,

I'm running through these Haskell exercises:

  http://dibblego.wordpress.com/2008/09/18/20-intermediate-haskell-exercises/

and I'm stuck at number 9:


class Misty m where
  banana :: (a -> m b) -> m a -> m b
  unicorn :: a -> m a

-- Exercise 9
-- Relative Difficulty: 6
instance Misty ((->) t) where
  banana = ???
  unicorn x = (\t -> x)


I can picture it when m is "[]" or "Maybe", but I can't wrap my head
around the banane implementation for "((->) t)".
I can see that this somewhat looks like a Monad, with unicorn = return
and banana = (flip >>=) or something. Perhaps some kind of reader
Monad?
Can anyone offer any insight?


Patrick

-- 
=====================
Patrick LeBoutillier
Rosemère, Québec, Canada