infixr 5 :-: data List a = Empty | a :-: (List a) deriving (Show, Read, Eq, Ord) myMap :: (a -> b) -> List a -> List b myMap _ Empty = Empty myMap f (x :-: xs) = f x :-: myMap f xs instance Functor List where fmap = myMap
テスト含むソースコード全体
