Re: arrow keys vs. C-f/b/n/p

[David Kastrup <dak@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Lennart Borgman <lennart.borgman@gmail.com>
>> Date: Sat, 12 Jun 2010 22:07:36 +0200
>> Cc: emacs-devel@gnu.org
>> 
>> >  abcde EDCBA xyz
>> >  ---------
>> >
>> > Now, what characters do you think should be displayed with the region
>> > face?
>> 
>> 
>> As I said in another message it would be "abcde CBA", i.e. exactly the
>> visual region that you now get when moving with the arrow keys so that
>> you get to C.
>
> But that doesn't make sense: the cursor traverses characters that you
> don't paint in the region face, and the region face is put on
> characters the cursor didn't move through.

I think "that doesn't make sense" will be unavoidable for some narrow
meaning of "sense" for some combinations of keypresses in mixed L2R-R2L
settings.

For me, the behavior makes perfect sense, and is, in some manner, even
telling us something beautiful about the structure of texts, just like
the equations of Special Relativity as opposed to the equations of
Newtonian mechanics "don't make sense" in some view, but tell us
something beautiful about the structure of spacetime.

We really should not try to define "makes sense" in terms of relations
that arise from fundamental properties of unidirectional text.

-- 
David Kastrup