{"image_url":null,"html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fkatahirado.hatenablog.com%2Fentry%2F20081208%2F1228747691\" title=\"Folding - \u4ed9\u53f0 Ruby Vim JavaScript \u30d5\u30ea\u30fc\u30e9\u30f3\u30b9\u30d7\u30ed\u30b0\u30e9\u30de\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","height":"190","provider_name":"Hatena Blog","author_name":"yuichi_katahira","author_url":"https://blog.hatena.ne.jp/yuichi_katahira/","blog_url":"https://katahirado.hatenablog.com/","version":"1.0","url":"https://katahirado.hatenablog.com/entry/20081208/1228747691","categories":["Scala","Ruby"],"provider_url":"https://hatena.blog","description":"Scala scala> def sum(lst: List[Int]) = (0 /: lst) ((x,y) => x+y) sum: (List[Int])Int scala> sum(List(1,2,3,4)) res10: Int = 10 ruby >> def sum(array) >> array.inject(0) {|sum,x| sum+x } >> end => nil >> sum([1,2,3,4]) => 10 Scala scala> def fac(n: Int)=(1 /: (1 to n)) (_ * _) fac: (Int)Int scala> fa\u2026","blog_title":"\u4ed9\u53f0 Ruby Vim JavaScript \u30d5\u30ea\u30fc\u30e9\u30f3\u30b9\u30d7\u30ed\u30b0\u30e9\u30de","published":"2008-12-08 23:48:11","width":"100%","type":"rich","title":"Folding"}