（その１４）拡張

blog014_003.hs

data Human = Human {h_name :: String}
data Neko = Neko {n_name :: String}
data Inu = Inu {i_name :: String}

class Aisatu a where
  hello :: a -> String
  goodMorning :: a -> String
  goodNight :: a -> String

instance Aisatu Human where
  hello x = "hello, " ++ h_name x
  goodMorning x = "Good Morning, " ++ h_name x
  goodNight x = "Good Night, " ++ h_name x

instance Aisatu Neko where
  hello x = "hello, " ++ n_name x
  goodMorning x = "Good Morning, " ++ n_name x
  goodNight x = "Good Night, " ++ n_name x

instance Aisatu Inu where
  hello x = "hello, " ++ i_name x
  goodMorning x = "Good Morning, " ++ i_name x
  goodNight x = "Good Night, " ++ i_name x