Re: delete-selection-mode (was: Put scroll-bar on right by default on UNIX.)

[Stephen J. Turnbull]

Alan Mackenzie writes:

 > Clearly the convenience benefit dominates for you; the accidental
 > explosion hazard dominates for me (in non-Emacs environments, where I
 > can't disable the (mis)feature).  I've no reason to suspect I'm unusual
 > here.

I'm sure you're not.  After all, I had exactly that experience ... for
about three days.

Note that in many non-Emacs environments, you also don't have decent undo.

 > It's "obviously" useful to be able to type extra text into an already
 > "existing" region.  The region is used for many things other than just
 > being deleted.

Could be, but I almost never use the region that way myself, and when
I do, C-x C-x does what I need (I don't need a visible region for that
use case, personally).

 > Do they?  How do we know there aren't lots of "veteran" users who don't
 > really know how to configure the thing?

Come now; if you're going to insist on being different to teach
newbies to use Emacs effectively, shouldn't that apply all the more to
using help and changing defaults for veterans?

 > I think we should also distinguish between pure new UI features, and
 > those that actively interfere with established usage.  My view is that we
 > should never make something default in Emacs if it's likely to provoke
 > the angry reaction "How do I disable this *!£$ing thing?".
 > delete-select-mode falls into this latter category.  So does
 > transient-mark-mode.

Guess what?  XEmacs did that experiment with zmacs-regions (~ t-m-m)
almost 15 years ago.  Oh, there was whining, and there was screaming,
and there were predictions of The Imminent End of the World as We Know
It (with which I quietly agreed).  But the switch was flipped,
zmacs-regions was made true by default, and you know what?  *Nobody
noticed!*  Some experienced users switched (as I did).  Many turned it
off in their init file.  The key is that nobody complained that they
gave it a real chance and still it sucked.

Since then there has been no question in my mind that changing
defaults is definitely an implement we should have in our toolbox.

 > Is there any evidence that delete-select-mode is instrinsically a good
 > thing, disregarding the fact that it has become common?

My personal experience.  I really didn't like it in theory, I found it
irritating in practice, but having given it a serious try, I now like
it, and miss it when I'm borrowing somebody's Emacs or something.

 > Where is the proof that d-s-m has proven itself efficient, rather than
 > being mainly an irritation?  That's a genuine question, not a rhetorical
 > one.

The proof of this pudding is in the eating.  It worked very well for
XEmacs with zmacs-regions, and even Richard now uses t-m-m.  I don't
know if it will work as well for delsel.

 > One reason people might have come to Emacs is to escape the (to them)
 > deity-awful key sequences they've been forced to use up to now.  It is
 > surely good to offer them an alternative.

Of course it's good to offer alternatives.  Whether that alternative
should be default or alternative option is an empirical question.  The
only way to really find out is to try it, *as default*.  If you see
some significant fraction of experienced users switching to the
default and none saying "I tried it and it sucked", it's probably a
good idea.