Emacs(Elisp): duplicate region or line. if same command repeated, then duplicate sate strings. 選択範囲がある場合は選択範囲を、選択範囲がない場合は、行を複製します。繰り返した場合、同じ文字列を複製し続けます。

duplicate-region-or-line.el

;;; 行／選択範囲の複製 (cmd+d)
;; gist-description: Emacs(Elisp): duplicate region or line.  if same command repeated, then duplicate sate strings.  選択範囲がある場合は選択範囲を、選択範囲がない場合は、行を複製します。繰り返した場合、同じ文字列を複製し続けます。
;; gist-id: 297fe973cde66b384fa1
;; gist-name: duplicate-region-or-line.el
;; gist-private: nil

(defvar previous-duplicate-region-or-line nil)
(defvar previous-duplicate-region-or-line-was-line nil)
(defun duplicate-region-or-line ()
  "Duplicate region or line."
  (interactive)
  (let* ((beg (if mark-active (region-beginning) (line-beginning-position)))
         (end (if mark-active (region-end) (line-end-position)))
         (strings (buffer-substring-no-properties beg end))
         (is-repeat (eq last-command this-command))
         (is-line (if is-repeat
                      previous-duplicate-region-or-line-was-line
                    (not (region-active-p))))
         (strings (if (region-active-p)
                      strings
                    (concat "\n" strings))))
    (if is-line
        (progn
          (end-of-line)
          (setq previous-duplicate-region-or-line-was-line is-line))
      (setq previous-duplicate-region-or-line-was-line nil))
    (if is-repeat
        (insert previous-duplicate-region-or-line)
      (insert strings)
      (setq previous-duplicate-region-or-line strings))))

(global-set-key (kbd "s-d") 'duplicate-region-or-line)