{"author_name":"faith_and_brave","type":"rich","url":"https://faithandbrave.hateblo.jp/entry/20111201/1322718742","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Ffaithandbrave.hateblo.jp%2Fentry%2F20111201%2F1322718742\" title=\" GADTs\u4f7f\u3063\u3066\u307f\u305f - Faith and Brave - C++\u3067\u904a\u307c\u3046\" 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/faith_and_brave/","title":" GADTs\u4f7f\u3063\u3066\u307f\u305f","blog_url":"https://faithandbrave.hateblo.jp/","version":"1.0","provider_url":"https://hatena.blog","height":"190","categories":["Haskell"],"width":"100%","blog_title":"Faith and Brave - C++\u3067\u904a\u307c\u3046","published":"2011-12-01 14:52:22","provider_name":"Hatena Blog","description":"\u3053\u306e\u30a8\u30f3\u30c8\u30ea\u306f\u3001Haskell Advent Calendar 2011\u306e\u53c2\u52a0\u8a18\u4e8b\u3067\u3059\u3002 \u4eca\u56de\u306f\u3001Haskell\u306eGHC\u62e1\u5f35\u3067\u3042\u308bGADTs(Generalized Algebraic Data Types : \u4e00\u822c\u5316\u4ee3\u6570\u30c7\u30fc\u30bf\u578b)\u3092\u8abf\u3079\u3066\u4f7f\u3063\u3066\u307f\u305f\u3068\u3044\u3046\u5185\u5bb9\u3092\u66f8\u3044\u3066\u307f\u307e\u3057\u305f\u3002 \u6700\u521d\u306b\u3001GADTs\u306fGHC\u62e1\u5f35\u306a\u306e\u3067\u3001\u4f7f\u7528\u3059\u308b\u306b\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u3057\u3066\u62e1\u5f35\u3092\u6709\u52b9\u306b\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\uff1a {-#LANGUAGE GADTs #-} \u307e\u305a\u306f\u69cb\u6587\u7684\u306a\u9055\u3044\u3092\u3001Maybe\u3092\u4f8b\u306b\u3057\u3066\u898b\u3066\u307f\u307e\u3057\u3087\u3046\u3002 \u901a\u5e38\u306e\u4ee3\u6570\u30c7\u30fc\u30bf\u578b\u3067\u306f\u3001Maybe\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u66f8\u304d\u307e\u3059\uff1a data Maybe a = Nothing | Jus\u2026","image_url":null}