sicp 习题 2.23

#lang planet neil/sicp
(define lst (list 57 321 88))
(define thing (lambda (x) (newline) (display x)))


(define (for-each thing lst)
  (cond ((not (null? lst))
         (thing (car lst))                     
        (for-each thing (cdr lst)))))
        
        
        

运行结果:

Welcome to DrRacket, version 5.3.3 [3m].
Language: planet neil/sicp; memory limit: 512 MB.
> (for-each thing lst)


57
321
88
>