sum 1 to 10

9lisp-003-homework-origin.scm

(define fact
  (lambda (n)
    (if (zero? n)
        1
        (* n (fact (- n 1))))))
(fact 5)

;; apply
(use srfi-1)
(define fact
  (lambda (n)
    (apply * (iota n 1))))
(fact 5)

;; fold
(use srfi-1)
(define fact
  (lambda (n)
    (fold * 1 (iota n 1))))
(fact 10)
; -> fold

;; cps
(define fact/cps
  (lambda (n cont)
    (if (zero? n)
        (cont 1)
        (fact/cps (- n 1)(lambda (x)
                           (cont (* x n)))))))
(fact/cps 5 (lambda (x) x))