{"categories":["gauche"],"version":"1.0","image_url":null,"author_name":"rsakamot","url":"https://rskmt.hateblo.jp/entry/20090331/1238488062","blog_title":"\u3055\u304b\u3082\u3068\u306e\u30d6\u30ed\u30b0","blog_url":"https://rskmt.hateblo.jp/","height":"190","provider_name":"Hatena Blog","published":"2009-03-31 17:27:42","type":"rich","provider_url":"https://hatena.blog","title":"\u7b2c7\u7ae0\u7df4\u7fd2\u554f\u984c","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Frskmt.hateblo.jp%2Fentry%2F20090331%2F1238488062\" title=\"\u7b2c7\u7ae0\u7df4\u7fd2\u554f\u984c - \u3055\u304b\u3082\u3068\u306e\u30d6\u30ed\u30b0\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","width":"100%","author_url":"https://blog.hatena.ne.jp/rsakamot/","description":"(define (tree-walk walker proc tree) (walker (lambda (elt) (if (list? #?=elt) (tree-walk walker proc elt) (proc elt))) tree)) (define (numbers-only-for-tree walker) (lambda (proc lis) (walker proc #?=(my-filter (lambda (x) (or (number? x) (pair? x))) lis)))) (tree-walk (numbers-only-for-tree map) (l\u2026"}