1 ;;;;;;;;;;;
3.1
2
3 (define (make-accumulator
base)
4 (lambda (num)
5 (
set!
base (+
base num))
6 base))
7
8 (define A (make-accumulator
5))
9
10 (A
10)
11 (A
10)
12
13 ;;;;;;;;;;
3.2
14
15 (define (make-
monitored f)
16 (let ((count
0))
17 (define (mf x)
18 (cond ((eq? x
'how-many-calls?) count)
19 ((eq? x
'reset-count) (set! count 0))
20 (
else (begin (
set! count (+ count
1))
21 (f x)))))
22 mf))
23
24 (define square (lambda (x) (*
x x)))
25 (define s (make-
monitored square))
26
27 (s
100)
28 (s
4)
29 (s
'how-many-calls?)
30 (s
'reset-count)
31 (s
'how-many-calls?)
先跳过了一些，等3.2后再看
开始用完全用Scheme来写
开始用Linux系统
转载于:https://www.cnblogs.com/tclan126/p/6523621.html
