Emacs copy region/line and comment at the same time

Question

I am trying to implement the following: duplicate the currently selected region or a line (if there is no selection) and comment out the original region with the help of comment-or-uncomment-region-or-line.

I figured I could use kill-region followed by yank but then my original selection is lost, so I can't comment. If on the other hand I comment first I will get both copies of my region commented out.

The other idea I have (which I think is better because I use evil-mode) is to use evil-yank and then evil-visual-restore to restore the selection so that I can comment it out. But I can't figure what arguments to pass to evil-yank to specify the selected region.

What am I missing here?

Answer 1

The main thing you are missing is function copy-region-as-kill.

(defun copy-and-comment-region (beg end &optional arg)
  "Duplicate the region and comment-out the copied text.
See `comment-region' for behavior of a prefix arg."
  (interactive "r\nP")
  (copy-region-as-kill beg end)
  (goto-char end)
  (yank)
  (comment-region beg end arg))