{"url":"https://zehnpaard.hatenablog.com/entry/2018/03/13/214540","type":"rich","height":"190","provider_name":"Hatena Blog","blog_url":"https://zehnpaard.hatenablog.com/","published":"2018-03-13 21:45:40","width":"100%","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fzehnpaard.hatenablog.com%2Fentry%2F2018%2F03%2F13%2F214540\" title=\"Thinking Functionally with Haskell\u52c9\u5f37\u30e1\u30e2: \u7b2c\uff14\u7ae0\uff12 concat/map/filter\u3001functor\u3068\u81ea\u7136\u5909\u63db\u3001\u540c\u4e00\u6027\u306e\u8a3c\u660e - Arantium Maestum\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","author_name":"zehnpaard","blog_title":"Arantium Maestum","version":"1.0","provider_url":"https://hatena.blog","image_url":null,"description":"\u30ea\u30b9\u30c8\u306b\u5bfe\u3059\u308b\u51e6\u7406\u306e\u6027\u8cea\u30fb\u6cd5\u5247\u3001Functor\u306b\u5bfe\u3059\u308b\u306e\u4e00\u822c\u5316\u3001\u6027\u8cea\u306e\u8a3c\u660e\u6cd5\u306b\u3064\u3044\u3066\u30e1\u30e2\uff1a \u307e\u305a\u306fconcat\u3001map\u3001filter\u306e\u5b9a\u7fa9\uff1a concat :: [[a]] -> [a] concat [] = [] concat (xs:xss) = xs ++ concat xss map :: (a -> b) -> [a] -> [b] map _ [] = [] map f (x: xs) = f x : map f xs filter :: (a -> Bool) -> [a] -> [a] filter _ [] = [] filter p (x:xs) | p x = x:fi\u2026","title":"Thinking Functionally with Haskell\u52c9\u5f37\u30e1\u30e2: \u7b2c\uff14\u7ae0\uff12 concat/map/filter\u3001functor\u3068\u81ea\u7136\u5909\u63db\u3001\u540c\u4e00\u6027\u306e\u8a3c\u660e","author_url":"https://blog.hatena.ne.jp/zehnpaard/","categories":["Haskell","Thinking Functionally with Haskell"]}