kiririmode https://blog.hatena.ne.jp/kiririmode/ 理系学生日記 https://kiririmode.hatenablog.jp/ SICP cons, car, cdr, set-car!, set-cdr! を local state と assignment で実現した以下の関数セット． (define (cons x y) (define (set-x! v) (set! x v)) (define (set-y! v) (set! y v)) (define (dispatch m) (cond ((eq? m 'car) x) ((eq? m 'cdr) y) ((eq? m 'set-car!) set-x!) ((eq? m 'set-cdr!) set-y!) (else (error "Undefined ope… 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fkiririmode.hatenablog.jp%2Fentry%2F20080329%2Fp3" title="問題3-20 (3.3.1 Mutable List Structure) - 理系学生日記" 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/k/kiririmode/20080328/20080328235815.png Hatena Blog https://hatena.blog 2008-03-29 00:00:02 rich https://kiririmode.hatenablog.jp/entry/20080329/p3 1.0 100%