Re: How to recognize keyboard insertion?

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sun, 01 Nov 2009 09:30:35 +0800
> From: Jason Rumney <jasonr@gnu.org>
> CC: David De La Harpe Golden <david@harpegolden.net>, 
>  emacs-devel@gnu.org
> 
> User types: ABCD(
> Displayed as: )DCBA

Yes.

> User types: ABCD(4
> Displayed as: 4)DCBA or (4DCBA? I suspect the first, as the user might 
> type something other than a number next

The first, yes.

> User types: ABCD(4+5)
> Displayed as: (4+5)DCBA regardless of how directionality of parens is 
> interpreted.

Yes.  But I don't understand the ``regardless'' part.  If you want to
know the resolved directionality of each paren, I can tell you what
the current algorithm does (what UAX#9 requires).

> User types: ABCD(4+5)*9
> Displayed as: (4+5)*9DCBA Parens here must be LTR

No, it's displayed as 9*(4+5)DCBA.

> I guess this is why the mirroring happens at keyboard driver level and 
> applications do not try to do it correctly, because in practice doing it 
> correctly results in text jumping around, confusing the user more than 
> it confuses them to manually fix the problems of a dumb implementation. 

Sorry, I don't understand: what jumping around are we talking about,
and how is mirroring related to that?