Re: Unicode confusables and reordering characters considered harmful, a simple solution

[Eli Zaretskii]

> From: Daniel Brooks <db48x@db48x.net>
> Cc: Yuri Khan <yuri.v.khan@gmail.com>,  cpitclaudel@gmail.com,
>   stefan@marxist.se,  monnier@iro.umontreal.ca,  emacs-devel@gnu.org
> Date: Wed, 03 Nov 2021 12:54:31 -0700
> 
> > Do you read Hebrew?  Those characters look like line noise there,
> > whereas the text with the default display is perfectly readable, and
> > most people won't even know these controls are there (as intended).
> 
> My suggestion is to only enable it by default in _programming modes_. It
> should remain disabled in ordinary prose like a TUTORIAL file.

What about comments and strings?  Are we going to pretend that RTL
scripts aren't used in those?

> > What for?  The absolute majority of people won't have any idea what is
> > the effect of each of these controls, and how it differs from others.
> > Even I many times need to talk myself through their effect on display.
> > The UBA spec weighs in at more than 30 pages of highly technical text,
> > and I don't expect people to memorize it by heart.
> 
> I totally agree, but I think that this is not very relevant. The whole
> point is for a programmer who is unaware of BiDi in general to go “WTF‽”
> when these characters show up in a source file one day, so that they can
> have something to ask questions about.
> 
> `what-cursor-position' will show the face, once a face is available, and
> it also shows the name of the character. Both are good ways for the user
> to find more information, and in principle we could have it show other
> information as well. We could pull a description from the Unicode
> database perhaps, or just add extra help messages for individual
> characters. Now that I think about it, maybe we should just show the
> docstring for the face right there next to the name. That would save me
> a step from time to time, if nothing else.

You are welcome to make such customizations in your Emacs.  My point
is that for a useful feature that doesn't get in the way when those
controls are used for legitimate purposes, and only highlights _text_
(NOT the controls!) whose appearance may have been altered by them for
questionable or suspicious reasons -- for such a useful feature what
you propose is not enough for having it in Emacs for everyone.  It is
a blunt weapon that I would be ashamed to install.