module Maybe where

--
-- 1
--
isJust :: Maybe a -> Bool
isJust (Just _) = True
isJust Nothing = False

isNothing :: Maybe a -> Bool
isNothing (Just _) = False
isNothing Nothing = True

--
-- 2
--
mayybee :: b -> (a -> b) -> Maybe a -> b
mayybee v f Nothing   = b
mayybee v f (Maybe x) = f x