{"description":"\u30e2\u30ca\u30c9\u3092\u7406\u89e3\u3059\u308b\u305f\u3081\u306bMaybe\u3092\u81ea\u4f5c\u3059\u308b\u3053\u3068\u306b\u3057\u305f\u306e\u3067\u3001\u9069\u5f53\u306b\u30b3\u30fc\u30c9\u3055\u3089\u3057\u3066\u307f\u308b\u3002\u30e2\u30ca\u30c9\u5f37\u8005\u306e\u65b9\u306e\u30c4\u30b3\u30c3\u30df\u3042\u308c\u3070\u3001\u3088\u3044\u30b3\u30f3\u30c6\u30f3\u30c4\u5316\u3059\u308b\u306e\u3067\u306f\u611f\u3002 data Option a = None | Some a deriving (Eq, Show) instance Functor Option where fmap f (Some x) = Some (f x) fmap f None = None getOrElse :: Option a -> a -> a getOrElse None v = v getOrElse (Some x) _ = x get :: Option a -> a\u2026","title":" Maybe\u3092\u81ea\u4f5c\u3057\u3066\u307f\u308b(Functor\u7de8)","url":"https://blog.j5ik2o.me/entry/2012/12/10/001008","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fblog.j5ik2o.me%2Fentry%2F2012%2F12%2F10%2F001008\" title=\" Maybe\u3092\u81ea\u4f5c\u3057\u3066\u307f\u308b(Functor\u7de8) - \u304b\u3068\u3058\u3085\u3093\u306e\u6280\u8853\u65e5\u8a8c\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","categories":["Haskell"],"published":"2012-12-10 00:10:08","width":"100%","image_url":null,"type":"rich","provider_url":"https://hatena.blog","provider_name":"Hatena Blog","author_url":"https://blog.hatena.ne.jp/j5ik2o/","blog_url":"https://blog.j5ik2o.me/","version":"1.0","author_name":"j5ik2o","height":"190","blog_title":"\u304b\u3068\u3058\u3085\u3093\u306e\u6280\u8853\u65e5\u8a8c"}