{"url":"https://sirocco.hatenadiary.org/entry/20130402/1364912071","provider_name":"Hatena Blog","published":"2013-04-02 23:14:31","categories":["Haskell"],"height":"190","author_name":"sirocco","version":"1.0","description":"Data.Foldable \u3053\u308c\u306fData.Foldable\u306b\u3042\u308b\u4f8b\u3067\u3059\u304c\u3001Tree\u578b\u306eFoldable\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u5b9a\u7fa9\u3059\u308b\u3053\u3068\u306b\u3088\u3063\u3066Foldable\u306b\u5b9a\u7fa9\u3055\u308c\u3066\u3044\u308b\u95a2\u6570\u3092\u4f7f\u7528\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002 Foldable\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u5b9a\u7fa9\u3059\u308b\u306b\u306f\u3001foldMap \u307e\u305f\u306ffoldr\u3092\u5b9a\u7fa9\u3059\u308c\u3070\u826f\u3044\u3089\u3057\u3044\u3002 import Data.Foldable import Data.Monoid data Tree a = Empty | Leaf a | Node (Tree a) a (Tree a) deriving Show instance Foldable Tree where foldMap \u2026","blog_url":"https://sirocco.hatenadiary.org/","blog_title":"sirocco \u306e\u66f8\u3044\u3066\u3082\u3059\u3050\u306b\u5fd8\u308c\u308b\u30e1\u30e2","image_url":null,"author_url":"https://blog.hatena.ne.jp/sirocco/","width":"100%","provider_url":"https://hatena.blog","type":"rich","title":"Foldable \u3092\u4f7f\u3063\u3066\u307f\u308b\u3002","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fsirocco.hatenadiary.org%2Fentry%2F20130402%2F1364912071\" title=\"Foldable \u3092\u4f7f\u3063\u3066\u307f\u308b\u3002 - sirocco \u306e\u66f8\u3044\u3066\u3082\u3059\u3050\u306b\u5fd8\u308c\u308b\u30e1\u30e2\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>"}