Convert number to list of digits

Question

How do I convert a number to a list of digits?

I am currently doing:

;; (num->list 12345) -> \'(1 2 3 4 5)
(define (num->list n)
  (local 
          


        

Answer 1

Here's how I'd do it in Racket:

(require srfi/1 srfi/26)
(define (digits->list num (base 10))
  (unfold-right zero? (cut remainder <> base) (cut quotient <> base) num))

This is the sort of problem unfold was designed for. :-D