RE: Is Elisp really that slow?

[Drew Adams]

> >I agree with Oscar that `comment-dwim' and `comment-region'
> >have different behaviors - so neither is a substitute
> >for the other.
> >
> >In particular, `comment-region' lets you also
> >uncomment, including unnest, comments.
> 
> To no waste bindings we could just modify comment-region to accept
> negative prefix to uncomment. So C-- M-; uncoments region, and M-;
> comments it. 

I don't get your point.  `comment-region' already
uncomments, with plain `C-u'.

> But now there will come another user saying that the dwim
> version is better... we will never agree in anything this way.

The point was that both `M-;' and `comment-region'
are useful, and that neither substitutes for the other.
It doesn't matter which one someone think is "better".
They're both available.

> >I use both, and I bind each to a short key sequence.
> >
> >More precisely, I leave `comment-dwim' on `M-;'
> >and I bind `C-x C-;' to a command similar to
> >`comment-region' but that I find more useful:
> >`comment-region-lines'.  It comments/uncomments
> >whole lines.
> >
> >(So it too differs from `comment-region' - so it
> >too is not an exact "replacement".)
> >
> >As for key bindings:
> >
> >Although I haven't bothered to change the binding of
> >`M-;', I think it's a shame and a waste to sacrifice
> >such a nice, short, _repeatable_ key sequence for a
> >command that does _nothing_ when you repeat it.
> >
> >Far better to use `M-;' for some command that keeps
> >doing something when repeated (just hold down `M-;').
> >That's what Emacs should do eventually, IMHO.  No
> >urgency, but someday, when we find a really useful
> >repeatable command...
> >
> >As for `comment-dwim': Since I use `C-x C-;'
> >(`comment-region-lines') for block commenting and
> >uncommenting, I never really use `M-;' for anything
> >other than an end-of-line comment.
> >
> >`M-;' used to be bound to a command that did only
> >that: `indent-for-comment'.  And since that's all
> >I really use `M-;' for, the rest of `comment-dwim'
> >is, yes, wasted and replaceable by `comment-region'
> >or my `comment-region-line'.  `M-;' for eol comment,
> >`C-x C-;' for commenting/uncommenting lines.
> >
> >(defun comment-region-lines (beg end &optional arg)
> >  "Like `comment-region', but comment/uncomment whole lines."
> >  (interactive "*r\nP")
> >  (when (> beg end)
> >    (setq beg  (prog1 end (setq end  beg))))
> >  (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)))
> 
> This is the king of features I would really support. Enable line or
> region by default. There is a package for that in melpa y find very
> useful.

I proposed it long ago to emacs-devel.  Other,
similar commands were also discussed.  Emacs-devel
decided not to go there (by adding such a command
or by giving it - or even `comment-region' - a
binding by default).  Apparently it was thought
that `M-;' is sufficient.  Giving something a DWIM
name makes it universally useful, I guess. ;-)

Well, `comment-region' still does have a "key"
binding in vanilla Emacs (at least in some modes),
but not a _keyboard_ key binding:

comment-region is on <menu-bar> <emacs-lisp> <comment-region>