blob: 5a2699d691432894a058a6188487cd4c0111bf6a (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
|
(import "macro") ; For unless
(defmacro assert (test)
`(unless ,test
(error "assert: value is false." ',test)))
(defun my-sum (sequence)
(let ((res 0))
(for ((xs sequence (cdr xs)))
((null xs) res)
(setq res (+ res (car xs))))))
(defun average-of-absolutes (values)
(assure <list> values)
;; requires non-null list
(assert (> (length values) 0))
(let ((res (quotient (my-sum (mapcar #'abs values)) (length values))))
;; must ensure positive result
(assert (>= res 0))
(assure <number> res)))
;; (average-of-absolutes '(1 3))
;; (average-of-absolutes '())
|