Comment-dwim-2

comment-dwim-2 is a replacement for the Emacs' built-in command comment-dwim, which includes more features and allows you to:

• comment/uncomment the current line (or region, if active)
• insert/kill end-of-line comments
• reindent end-of-line comments

comment-dwim-2 picks one behavior depending on the context but can also be repeated several times to switch between the different possible behaviors.

Demo

comment-dwim-2 used 3 times in a row:

Setup

Install this package from MELPA.

Then, add your own key binding, for instance:

(use-package comment-dwim-2
  :bind
  ("M-;" . comment-dwim-2))

or

(keymap-global-set "M-;" #'comment-dwim-2)

Detailed use cases

Comment/uncomment the region

Comment current line

Uncomment current line

Insert comment (repeat the command)

Kill comment (repeat the command)

Reindent comment (call the command with a prefix argument)

Org-mode support

comment-dwim-2 works as expected inside org-mode code blocks. In regular org-mode content, it fallbacks to org-toggle-comment:

Customization

When commenting a region, comment-dwim-2 will by default comment the entirety of the lines that the region spans (i.e. a line will be fully commented even if it is partly selected):

In Lisp modes, however, comment-dwim-2 will strictly comment the region as commenting whole lines could easily lead to unbalanced parentheses.

If you always want to fully comment lines (Lisp modes included), add this to your configuration file:

(setopt comment-dwim-2-region-function #'comment-dwim-2-comment-or-uncomment-lines)

If you only want to comment the selected region (like comment-dwim does), add this:

(setopt comment-dwim-2-region-function #'comment-dwim-2-comment-or-uncomment-region)