@@ -61,17 +61,3 @@ mapMaybe f (x::xs) =
6161 case f x of
6262 Nothing => mapMaybe f xs
6363 Just j => j :: mapMaybe f xs
64−
65−--------------------------------------------------------------------------------
66−-- Class instances
67−--------------------------------------------------------------------------------
68−
69−instance Functor Maybe where
70− fmap f Nothing = Nothing
71− fmap f (Just j) = Just (f j)
72−
73−instance Monad Maybe where
74− return = Just
75−
76− (>>=) Nothing m = Nothing
77− (>>=) (Just j) m = m j