{"image_url":null,"description":"9.2 \u4ee3\u6570\u7684\u30c7\u30fc\u30bf\u578b \u5f15\u6570\u306e\u306a\u3044\u95a2\u6570\u306f\u5b58\u5728\u3057\u306a\u3044 \u3046\u301c\u3080\u3001\u4eca\u307e\u3067\u8003\u3048\u3066\u3082\u307f\u306a\u304b\u3063\u305f\u8996\u70b9\u3067\u3059\u3002 \u5f15\u6570\u306e\u306a\u3044\u95a2\u6570\u306f\u5b58\u5728\u3057\u306a\u3044\u3002 \u4e00\u65b9\u3067\u30c7\u30fc\u30bf\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u306f\u5f15\u6570\u306a\u3057\u3082\u3042\u308a\u3002 \u5408\u308f\u305b\u3066\u899a\u3048\u3066\u304a\u304d\u307e\u3059\u3002 \u5217\u6319\u578b\u30b9\u30bf\u30a4\u30eb\u3068\u5171\u7528\u4f53\u578b\u30b9\u30bf\u30a4\u30eb \u672c\u6587\u4e2d\u306b\u3042\u3063\u305fBool\u4ee5\u5916\u306e\u5217\u6319\u578b\u30b9\u30bf\u30a4\u30eb\u306e\u4ee3\u6570\u7684\u30c7\u30fc\u30bf\u578b\u3092Prelude\u30e2\u30b8\u30e5\u30fc\u30eb\u306e\u4e2d\u3067\u63a2\u3057\u3066\u307f\u307e\u3057\u305f\u3002 data Maybe a = Nothing | Just a deriving (Eq, Ord, Read, Show) data Either a b = Left a | Right b deriving (Eq, Ord, Read, Show) d\u2026","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fyohpapa.hatenadiary.org%2Fentry%2F20100722%2F1279749843\" title=\" \u578b\u3068\u578b\u30af\u30e9\u30b9 - Yohpapa\u2019s note\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","author_url":"https://blog.hatena.ne.jp/yohpapa/","published":"2010-07-22 07:04:03","blog_url":"https://yohpapa.hatenadiary.org/","width":"100%","type":"rich","title":" \u578b\u3068\u578b\u30af\u30e9\u30b9","author_name":"yohpapa","provider_name":"Hatena Blog","version":"1.0","blog_title":"Yohpapa\u2019s note","provider_url":"https://hatena.blog","categories":["haskell"],"url":"https://yohpapa.hatenadiary.org/entry/20100722/1279749843","height":"190"}