gistfile1.scm

(use gauche.sequence)

;; (xrotate '(x a b c d e) 3) -> (a b c x d e) etc.
(define (xrotate lis n)
  `(,@(subseq lis 1 (+ n 1)) ,(car lis) ,@(drop lis (+ n 1))))

(define (digit->column n)
  `(#\# ,@(xrotate '(#\o #\|) (div n 5)) #\# ,@(xrotate '(#\| #\o #\o #\o #\o) (mod n 5)) #\#))

(define (num->columns num width)
  (map ($ digit->column $ digit->integer $) (format "~v,'0d" width num)))
  
(define *border* (make-list 10 #\#))

(define (soroban num :optional (width 8))
  (for-each print (apply map string `(,*border* ,@(num->columns num width) ,*border*))))