RE: [PATCH] newcomment.el (comment-line): New command.

[Drew Adams]

>>    C-a C-SPC C-n M-;
>>
>> works for me when I need it.  M-x comment-line RET is much longer (even
>> if you shorten it with something like partial-completion), so for such
>> a command to make sense, you'd need a key binding for it.
> 
> Yes, you would. I didn't mention keybinds yet, because I was tackling this by 
> parts. 
> 
> I bind it to `C-;'. Another viable key might be `C-M-;'. But it definitely
> needs a key. 
>
> When you want to comment/uncomment something between 1 and 9 lines, it
> always requires less keypresses than the M-; alternative.
> Besides, commenting a single line is such a common scenario, I find it
> deserves a single key instead of a 4 key combo. 
> It's also something that a lot of IDE's assign to a hotkey, so I'm sure
> I'm not the only one that finds it useful. :-) And people who come from
> other editors are sure to miss it.

FWIW, I use a variant of `comment-region' (below).  I bind it to
`C-x C-;'.  (The other, repeatable, keys you mention are too good to
waste on a non-repeating command.)

(defun comment-region-lines (beg end &optional arg)
  "Like `comment-region' (which see), but comment/uncomment whole lines."
  (interactive "*r\nP")
  (if (> beg end) (let (mid) (setq mid beg beg end end mid)))
  (let ((bol  (save-excursion (goto-char beg)
                              (line-beginning-position)))
        (eol  (save-excursion (goto-char end)
                              (if (bolp) (point) (line-end-position)))))
    (comment-region bol eol arg)))

If the region is empty then it comments the current line.

(But it does not distinguish active from inactive region.
That would be another possible behavior choice.)

I use this all the time.  I use `M-;' (`comment-dwim') only
for an end-of-line comment (as in the good old days).  I find
that `M-;' is quite poor for commenting and uncommenting the
region (including nesting and unnesting comment levels etc.).

`comment-region' is much better for that, IMO.  And as enhanced
above, it comments whole lines, which is what I typically want.