Skip to content

Instantly share code, notes, and snippets.

@kwrooijen kwrooijen/dec->bin.scm
Last active Nov 28, 2015

Embed
What would you like to do?
Decimal to Binary conversion options in Scheme
;; Very clean, but is not tail recursive!
(define (dec->bin n)
(cond ((zero? n) '())
(else (cons (remainder n 2)
(dec->bin (quotient n 2))))))
;; Not so clean, but is tail recursive.
(define (dec->bin n)
(letrec ((recc (lambda (acc n)
(cond ((zero? n) acc)
(else (recc (cons (remainder n 2) acc)
(quotient n 2)))))))
(recc '() n)))
;; Not much worse than the cleanest one, but uses optional args.
(define* (dec->bin n #:optional (acc '()))
(cond ((zero? n) acc)
(else (dec->bin (quotient n 2)
(cons (remainder n 2) acc)))))
(dec->bin 9) ;; => '(1 0 0 1)
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.
You signed in with another tab or window. Reload to refresh your session. You signed out in another tab or window. Reload to refresh your session.