blob: 21a557c12452f9ca3131df976e136c5b91f22c85 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
#lang racket
(define (accumulate combiner null-value term a next b)
(define (iter a result)
(if (> a b)
result
(iter
(next a)
(combiner
(term a)
result))))
(iter null-value a))
(define (accumulate combiner null-value term a next b)
(if (> a b)
null-value
(combiner
(term a)
(accumulate
combiner
null-value
term (next a) next b))))
(define (sum term a next b)
(accumulate
(lambda (x y) (+ x y))
0
term a next b))
(define (product term a next b)
(accumulate
(lambda (x y) (* x y))
1
term a next b))
(sum id 0 inc 8)
(product id 1 inc 3)
|
