{"version":"1.0","categories":["scheme"],"type":"rich","provider_url":"https://hatena.blog","width":"100%","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fhigepon.hatenablog.com%2Fentry%2F20080102%2F1199254971\" title=\" with-gensym\u30de\u30af\u30ed - higepon blog\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","provider_name":"Hatena Blog","description":"\u30c6\u30b9\u30c8\u306e\u304a\u4f9b\u306b\u3069\u3046\u305e\u3002 (define (make-gensym) (let1 i 0 (lambda () (set! i (+ i 1)) (string->symbol (format \"G~d\" i))))) (define-macro with-gensym (lambda body (let ([org (gensym)] [ret (gensym)]) `(let1 ,org gensym (set! gensym ,(make-gensym)) (let ((,ret (begin ,@body))) (set! gensym ,org) ,ret))))) (with-gen\u2026","image_url":null,"author_name":"higepon","published":"2008-01-02 15:22:51","title":" with-gensym\u30de\u30af\u30ed","blog_title":"higepon blog","author_url":"https://blog.hatena.ne.jp/higepon/","height":"190","url":"https://higepon.hatenablog.com/entry/20080102/1199254971","blog_url":"https://higepon.hatenablog.com/"}