{"type":"rich","description":"\u3042\u3041\u3001assoc\u3057\u3066\u3001set-cdr!\u3059\u308c\u3070\u3001alist\u304c\u66f4\u65b0\u3067\u304d\u308b\u306e\u304b\u3002\u3059\u308b\u3068\u3001\u30ea\u30b9\u30c8\u306e\u4e2d\u306e\u30b7\u30f3\u30dc\u30eb\u306e\u6570\u3092\u6570\u3048\u305f\u304f\u306a\u3063\u305f\u3089\u3001\u3053\u3046\u66f8\u3051\u308b\u3002 (define (collect l) (let ((collects '())) (for-each (lambda (key) (let ((record (assoc key collects))) (if record (set-cdr! record (+ 1 (cdr record))) (set! collects (cons (cons key 1) collects))))) l) collects)) (collect '(a a a \u2026","blog_url":"https://boxnos.hatenablog.com/","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fboxnos.hatenablog.com%2Fentry%2F20080508%2F1210223464\" title=\" SICP\u3092\u8aad\u3080(106) 3.3.3 - assoc - \u30dc\u30af\u30ce\u30b9\" 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/tanakaBox/","blog_title":"\u30dc\u30af\u30ce\u30b9","provider_name":"Hatena Blog","height":"190","categories":["Scheme"],"title":" SICP\u3092\u8aad\u3080(106) 3.3.3 - assoc","image_url":null,"provider_url":"https://hatena.blog","version":"1.0","author_name":"tanakaBox","width":"100%","url":"https://boxnos.hatenablog.com/entry/20080508/1210223464","published":"2008-05-08 14:11:04"}