小编Ron*_*nan的帖子

以下两段代码看起来非常相似.但是必须有一些差异,我希望有人可以指出它们.

data Animal = Cat | Dog
speak :: Animal -> String
speak Cat = "meowh"
speak Dog = "wouf"

和

data Animal = Animal { speak :: String }
cat = Animal { speak = "meowh"}
dog = Animal { speak = "wouf" }