Tentative diagnosis of TMM's problem. [Re: Enabling Transient Mark Mode by default]

[Alan Mackenzie <acm@muc.de>]

Hi, Stefan,

On Wed, Feb 20, 2008 at 11:52:32AM -0500, Stefan Monnier wrote:
> Whenever I use "emacs -Q" or some similar "vanilla Emacs", the first
> thing that I'm urged to do is M-x transient-mark-mode (and it was
> already N°1 back when fotn-lock-mode wasn't the default).

> Of course, I'm sure I'd be able to learn to live without it.  It seems
> like an option affect people *very* strongly, so those who want it
> *really* want it, and those who don't *really* don't.

Strongly agreed!  It should be obvious, really - using Emacs with TMM is
so radically different from using it without, that it's difficult to
imagine anybody not being unhappy with (at least) one of these options.

Anyhow, thanks for actually giving positive reasons for favouring TMM.
They've been pretty much missing, so far in the thread.

After thinking your next paragraphs over, I think I can see the big
problem with TMM:

> So, that's for my personal preference.  As to why turn it on *by
> default*, here are some reasons why I think it should be ON by default:

> - Visual feedback about the mark's position and active status.
>   I and all (X)Emacs users I know personally (i.e. off-this-list) and
>   with whom I've talked about transient-mark-mode use
>   transient-mark-mode (or its XEmacs equivalent) and find it difficult
>   to use Emacs without it because of the lack of visual feedback about
>   where the mark really is.  I do not claim that this small group of
>   people is representative, but it does seem relevant.

> - Extended semantics for various commands.
>   Many commands now offer to operate on the region if the region is
>   active but only when transient-mark-mode is ON.
>   This functionality is now also available to non-tmm-users via the
>   temporary-transient-mark-mode (C-SPC C-SPC), admittedly, but while
>   C-SPC C-SPC is easy enough to use, I always find myself selecting the
>   region *before* knowing that I want to use such a command (or
>   selecting the region with something else than C-SPC, typically
>   C-M-SPC), so I end up having to use C-u C-x C-x which I find a lot
>   more inconvenient.

And that problem is, what on earth do these two facets of TMM have to do
with eachother?  Why should you have to "suffer" the visual effects of
TMM, if you just want to use the "extended semantics", and why can you
only highlight the region as a side effect of doing something else?

I think that if we partitioned TMM into the command `highlight-region',
and the other stuff, most of the acrimony on this thread would abate.
highlight-region probably deserves its own key binding.

> -- Stefan

-- 
Alan Mackenzie (Nuremberg, Germany).