{"image_url":null,"type":"rich","author_name":"Pocket7878_dev","height":"190","description":"\u8907\u6570\u306e\u7f6e\u63db\u3092\u5408\u6210\u3057\u305f\u308a\u3057\u305f\u3044\u5834\u9762\u304c\u3042\u308a\u307e\u3057\u305f\u3002 symm.hs module Symm(Symmetric(Symm),clean) where import Data.List import Data.Monoid data Symmetric a = Symm [(a,a)] deriving (Show,Eq) conc :: Eq a => [(a, a)] -> [(a, a)] -> [(a, a)] conc as [] = as conc [] bs = bs conc (a@(f,t):as) bs = a':conc as restBs where a' = conc' a\u2026","blog_url":"https://tech-blog.pocket7878.com/","published":"2013-05-14 00:40:47","author_url":"https://blog.hatena.ne.jp/Pocket7878_dev/","version":"1.0","title":"\u7f6e\u63db\u306e\u5408\u6210","provider_url":"https://hatena.blog","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Ftech-blog.pocket7878.com%2Fentry%2F2013%2F05%2F14%2F004047\" title=\"\u7f6e\u63db\u306e\u5408\u6210 - Let&#39;s write \u03b2\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","categories":["Haskell"],"url":"https://tech-blog.pocket7878.com/entry/2013/05/14/004047","provider_name":"Hatena Blog","blog_title":"Let's write \u03b2","width":"100%"}