{"version":"1.0","title":"Thinking Functionally with Haskell\u52c9\u5f37\u30e1\u30e2: \u7b2c\uff14\u7ae0\u554f\u984c\uff11","provider_name":"Hatena Blog","categories":["Haskell","Thinking Functionally with Haskell"],"author_name":"zehnpaard","published":"2018-03-15 11:28:49","height":"190","image_url":null,"provider_url":"https://hatena.blog","width":"100%","description":"Exercise A null :: [a] -> Bool null [] = True null _ = False \u3068\u3044\u3046\u5b9a\u7fa9\u3092 null = (==[]) \u3068\u5909\u3048\u3066\u3082\u5927\u4e08\u592b\u304b\uff1f\u3068\u3044\u3046\u554f\u984c\u3002 \u5b9f\u969b\u4f7f\u3063\u3066\u307f\u308b\u3068\u5927\u4e08\u592b\u305d\u3046\u306a\u306e\u3060\u304c\uff1a Prelude> null = (==[]) Prelude> null [] True Prelude> null [1] False Prelude> null [True] False Prelude> null [False] False \u5ff5\u306e\u305f\u3081\u3001\u578b\u3092\u8abf\u3079\u3066\u307f\u308b\uff1a Prelude> :t null null :: Eq t => [t] -> Bool\u2026","author_url":"https://blog.hatena.ne.jp/zehnpaard/","url":"https://zehnpaard.hatenablog.com/entry/2018/03/15/112849","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fzehnpaard.hatenablog.com%2Fentry%2F2018%2F03%2F15%2F112849\" title=\"Thinking Functionally with Haskell\u52c9\u5f37\u30e1\u30e2: \u7b2c\uff14\u7ae0\u554f\u984c\uff11 - 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>","blog_url":"https://zehnpaard.hatenablog.com/","blog_title":"Arantium Maestum","type":"rich"}