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

(require 'cl-lib)
(require 'dwim)
(require 'subr-x)

(defun enum (&optional beg end)
  "Enumerate each line from BEG to END, counting from one.
Use SUF as a suffix to the digits inserted.
BEG defaults to the beginning of the buffer,
END defaults to the end of the buffer,"
  (interactive (use-region))
  (unless beg
    (setq beg (point-min)))
  (unless end
    (setq end (point-max)))
  (goto-char beg)
  (let*((lns (count-lines beg end))
        (pad (length (number-to-string lns))))
    (cl-loop
      for line from 1 to lns
      do (goto-char (pos-bol))
         (insert
           (format "%s%s"
             (string-pad (number-to-string line) pad nil t) ". "))
         (forward-line))))

(provide 'enum)