blob: d17f20c900f589058cf644a7c0601694fa27e1a7 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
|
(define (fold f acc xs)
(if (null? xs)
acc
(fold f (f acc (car xs)) (cdr xs))))
(define (sum xs) (fold + 0 xs))
(define (range start stop step)
(if (>= start stop)
'()
(cons start (range (+ start step) stop step))))
(define (filter predicate xs)
(if (null? xs)
'()
(let* ((x (car xs))
(filtered (filter predicate (cdr xs))))
(if (predicate x) (cons x filtered) filtered))))
|
