ypooo https://blog.hatena.ne.jp/ypooo/ ypooo’s diary https://ypooo.hatenablog.com/ LISP 関数型 ### 4. root-domain 関数 ypooo.hatenablog.com (defun root-domain (url) (handler-case (let* ((uri (puri:parse-uri url)) (host (or (puri:uri-host uri) "")) (parts (split-sequence #\. host)) (n (length parts))) (cond ((<= n 2) host) ((and (>= n 3) (member (format nil "~A.~A" (nth (- n 2) parts) (nth (- n … 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fypooo.hatenablog.com%2Fentry%2F2026%2F04%2F25%2F053011" title="PythonプログラマーのためのCommon Lispコード解説 04 - ypooo’s diary" class="embed-card embed-blogcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;"></iframe> https://cdn-ak.f.st-hatena.com/images/fotolife/y/ypooo/20260425/20260425055449.jpg Hatena Blog https://hatena.blog 2026-04-25 05:30:11 rich https://ypooo.hatenablog.com/entry/2026/04/25/053011 1.0 100%