（その１４）型クラス

blog014_002.hs

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

class Hello a where
  hello	:: a -> String

instance Hello Human where
  hello h = "hello, " ++ h_name h

instance Hello Neko where
  hello n = "hello, " ++ n_name	n