chuck.rkt

#lang racket
(require srfi/26)
(require racket/match)

(define (fmt-src-list input-str)
  (define bl (map (cut char->integer <>)
          (string->list input-str)))
  (string-join (for/list ([x bl])
         (format "~a" (number->string x 2))) ""))

(define (gen-unary input [prev-input #f])
  (if (eq? input prev-input) "0"
      (match input
    [#\1 " 0 0"]
    [#\0 " 00 0"])))

(define (run)
  (define bstr (fmt-src-list "abcd"))
  (for/fold ([prev #f]) ([i bstr])
    (printf "~a" (gen-unary i prev)) i)
  (printf "\n"))

(run)
 ;; 0 00 00 0000 0 000 00 000 0 0 00 0 0 00 00 000 0 0000 00 00 0 0 00 00