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

[Eli Zaretskii]

> From: Yuri Khan <yuri.v.khan@gmail.com>
> Date: Thu, 4 Nov 2021 01:45:17 +0700
> Cc: Daniel Brooks <db48x@db48x.net>, Clément Pit-Claudel 
> <cpitclaudel@gmail.com>, 
>       Stefan Kangas <stefan@marxist.se>, Stefan Monnier 
> <monnier@iro.umontreal.ca>, 
>       Emacs developers <emacs-devel@gnu.org>
> 
> On Thu, 4 Nov 2021 at 00:56, Eli Zaretskii <eliz@gnu.org> wrote:
> 
> > The problem with these remappings is that you then get to somehow
> > discern between the remapped characters and the real characters which
> > look identically on display.
> 
> Real characters are fontified as whichever syntax unit they belong to.
> Remapped characters are fontified as whitespace-space-face or
> whitespace-hspace-face depending on whether you add them to
> whitespace-space-regexp or whitespace-hspace-regexp.

I just used what Daniel posted, and that doesn't display the remapped
characters in any distinct face.  Gotta tinker?

> > Also, this will disrupt alignment
> 
> We already have this issue with TABs — when a tab would expand to a
> single space, a remapped tab expands to its replacement glyph and a
> whole tab-width’s worth of spaces. Yes, it’s slightly annoying.

Yes, it's a general problem with remapping.

> > and make text using these controls
> > much harder to read.  E.g., the few places in TUTORIAL.he which use
> > those controls are barely readable after turning the above on.
> 
> I tried that and I find it okay.

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).

> > Anyway, if one wants to be able to highlight certain characters on
> > display, one could also use highlight-regexp, I think.
> 
> One does not only want to highlight, but also to actually see and
> distinguish certain characters

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.