1 665c255d 2023-08-04 jrmu (define (test-case actual expected)
 2 665c255d 2023-08-04 jrmu   (newline)
 3 665c255d 2023-08-04 jrmu   (display "Actual:   ")
 4 665c255d 2023-08-04 jrmu   (display actual)
 5 665c255d 2023-08-04 jrmu   (newline)
 6 665c255d 2023-08-04 jrmu   (display "Expected: ")
 7 665c255d 2023-08-04 jrmu   (display expected)
 8 665c255d 2023-08-04 jrmu   (newline))
 9 665c255d 2023-08-04 jrmu 
10 665c255d 2023-08-04 jrmu (define (append! x y)
11 665c255d 2023-08-04 jrmu   (set-cdr! (last-pair x) y)
12 665c255d 2023-08-04 jrmu   x)
13 665c255d 2023-08-04 jrmu 
14 665c255d 2023-08-04 jrmu (define (last-pair x)
15 665c255d 2023-08-04 jrmu   (if (null? (cdr x))
16 665c255d 2023-08-04 jrmu       x
17 665c255d 2023-08-04 jrmu       (last-pair (cdr x))))
18 665c255d 2023-08-04 jrmu 
19 665c255d 2023-08-04 jrmu (define x (list 'a 'b))
20 665c255d 2023-08-04 jrmu (define y (list 'c 'd))
21 665c255d 2023-08-04 jrmu (define z (append x y))
22 665c255d 2023-08-04 jrmu (test-case z '(a b c d))
23 665c255d 2023-08-04 jrmu (test-case (cdr x) '(b))
24 665c255d 2023-08-04 jrmu (define w (append! x y))
25 665c255d 2023-08-04 jrmu (test-case w '(a b c d))
26 665c255d 2023-08-04 jrmu (test-case (cdr x) '(b c d))