- 798 名前：デフォルトの名無しさん mailto:sage [2007/12/22(土) 04:24:14 ]
- ;andを使った場合
(define (assoc key alist)
(let loop ((ls alist))
(and (pair? ls)
(if (equal? key (caar ls))
(car ls)
(loop (cdr ls))))))
;andを使わない場合
(define (assoc key alist)
(let loop ((ls alist))
(cond ((null? ls)
#f)
((equal? key (caar ls))
(car ls))
(else
(loop (cdr ls))))))
