;;; -*- lexical-binding: t -*-
;;
;; this file:
;;   https://dataswamp.org/~incal/emacs-init/scale.el
;;
;; Moved:
;;   https://dataswamp.org/~incal/emacs-init/draw.el

(defun scale (end step &optional cur)
  (or cur (setq cur 0))
  (when (<= cur end)
    (let* ((digit-str (if (zerop (% cur step))
                          (format "%s" cur)
                        "."))
           (digit-len (length digit-str)))
      (insert digit-str)
      (scale end step (+ digit-len cur)))))

(defun scale-simple (&optional end)
  (interactive "P")
  (let* ((e (or (and (listp end) (car end))
                (if (numberp end)
                    end
                  30)))
         (step (max 1 (/ e 10))))
     (scale e step)))

;; C-u     M-x scale-simple RET 01234
;; C-u C-u M-x scale-simple RET 012345678910121416
;;         M-x scale-simple RET 0..3..6..9..12.15.18.21.24.27.30
;; C-u 100 M-x scale-simple RET 0.........10........20........30..[..]..100

(provide 'scale)