{"categories":["Haskell","Scala"],"type":"rich","provider_url":"https://hatena.blog","version":"1.0","height":"190","title":" Maybe\u3092\u81ea\u4f5c\u3057\u3066\u307f\u308b(Monad\u7de8 \u305d\u306e2)","author_url":"https://blog.hatena.ne.jp/j5ik2o/","description":"do\u5f0f\u3067\u306e\u30e2\u30ca\u30c9\u306e\u8a18\u8ff0\u65b9\u6cd5\u306b\u3064\u3044\u3066\u7c21\u5358\u306b\u307e\u3068\u3081\u308b\u3002 Some 1 >>= \\x -> Some(x+2) \u3092do\u5f0f\u306b\u66f8\u304d\u76f4\u3059\u3068 apply = do a <- Some 1 Some $ a + 2 Monad\u306b\u306freturn\u304c\u3042\u308b\u306e\u3067\u305d\u308c\u306b\u66f8\u304d\u63db\u3048\u308b\u3002 apply = do a <- return 1 :: Option Int return $ a + 2 \u95a2\u6570\u306e\u5f15\u6570\u306bOption\u3092\u53d7\u3051\u53d6\u308b\u5834\u5408\u306f\u3053\u3093\u306a\u611f\u3058\u3002 apply :: Option Int -> Option Int apply op = do a <- op return $ a + 1 \u307e\u3041\u3001\u3053\u308c\u3060\u3051\u306e\u8aac\u660e\u3060\u3068\u66f8\u304d\u65b9\u304c\u9055\u3046\u3060\u3051\u2026","provider_name":"Hatena Blog","url":"https://blog.j5ik2o.me/entry/2012/12/16/114208","author_name":"j5ik2o","width":"100%","image_url":null,"published":"2012-12-16 11:42:08","blog_title":"\u304b\u3068\u3058\u3085\u3093\u306e\u6280\u8853\u65e5\u8a8c","blog_url":"https://blog.j5ik2o.me/","html":""}