Scheme: Insertion Sort

InsertionSort.scm

;; same as the merge function in MergeSort.scm
(define (insert L M)
	(if (null? L) M
		(if (null? M) L
			(if (< (car L) (car M))
				(cons (car L) (insert (cdr L) M))
				(cons (car M) (insert (cdr M) L))))))

;; another insert function
;; need to modify the first para in insertionsort function to (car L)
(define (insert2 x L)
	(if (null? L) (list x)
		(let ((y (car L)) (M (cdr L)))
			(if (< x y)
				(cons x L)
				(cons y (insert2 x M))))))

;; Exp. (insertionsort '(4 2 10 3 -1 5)) ==> (-1 2 3 4 5 10)
(define (insertionsort L)
	(if (null? L) '()
		(insert (list (car L)) (insertionsort (cdr L)))))