@@ -70,6 +70,9 @@ instance Show a => Show (Maybe a) where
71---- Functor instances
71---- Functor instances
73+instance Functor IO where
74+ fmap f io = io_bind io (io_return . f)
73instance Functor Maybe where
76instance Functor Maybe where
74 fmap f (Just x) = Just (f x)
77 fmap f (Just x) = Just (f x)
75 fmap f Nothing = Nothing
78 fmap f Nothing = Nothing