Re: delete-selection-mode

[David Kastrup]

Stefan Monnier <address@hidden> writes:

>> I also think that the distinction between kill-region and
>> delete-region would be more confusing than helpful to a beginner.
>
> Indeed.
>
>> OK.  The penalty for that convenience is having your region explode and
>> disappear when you accidentally type a self-insert character (or arrow
>> key).  This might happen if you hit the x before the M in M-x, or
>> something like that.  Or, you might regionify a defun with C-M-h for some
>> reason and accidentally lose it.
>
> These are very valid concerns, and even if we don't enable delsel by
> default, I think we should try and come up with ways to reduce the
> pain.  E.g. making sure that you can revert the damage with `undo'
> (e.g. the delsel behavior should only affect buffer where undo is
> enabled; and maybe undoing a self-insert which also deleted the region
> might undo the self-insert, undo the delete-region *and* re-activate
> the region).

I already mentioned the pattern C-y C-x C-x for inserting/modifying at
the top of a yanked insertion.

> delsel only applies to active regions, so it shouldn't affect users
> when t-m-m is disabled.

We have temporary transient mark mode, which is also turned on with
mouse selections.

> Many things have fallen into this category in the past:
> - X11 (need to use -nw).
> - menu-bar
> - tool-bar
> - scroll-bar
> - fringes
> - blinking-cursor
> - t-m-m
> - font-lock
> - mouse-1-click-follows-link
> - "prettification" of info buffers

None of those destroy your text.

>> Is there any evidence that delete-select-mode is instrinsically a
>> good thing, disregarding the fact that it has become common?
>
> For DEL, I think it is very natural, yes.  For self-insert, I'm not
> really sure: I haven't been annoyed by it, but I haven't used it much
> either.

I think it is somewhat natural after mouse selections: after all, there
would be little point in mouse-selecting a region only to insert at one
end of the region.  There is the possible use of double/triple-clicking
in order to _move_ fast to beginning of word/line, but I don't think
that people make use of that much.

So something which extends mouse-region-delete-keys' functionality to
self-insert would not bother me.

-- 
David Kastrup