342 Sum / Map Example

sum_map.sc

(define sum 
	(lambda (lst) 
		(if (null? lst)
		    0
		    (+ (car lst) (sum (cdr lst)))
		)
	)
)

(define map 
	(lambda (f lst)
		(if (null? lst)
		    (list)
		    (cons (f (car lst)) (map f (cdr lst)))
		)
	)
)
		    
(define a_list (list 1 2 3 4))
(define addone (lambda (x) (+ x 1)))

(sum (map addone a_list))