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

[Eli Zaretskii]

> Date: Wed, 03 Nov 2021 20:21:50 +0000
> From: Gregory Heytings <gregory@heytings.org>
> cc: juri@linkov.net, cpitclaudel@gmail.com, stefan@marxist.se, 
>     emacs-devel@gnu.org, db48x@db48x.net, monnier@iro.umontreal.ca, 
>     yuri.v.khan@gmail.com
> 
> 
> >>>> Anyway, if one wants to be able to highlight certain characters on 
> >>>> display, one could also use highlight-regexp, I think.
> >>>
> >>> Or markchars.el with markchars-what customized to 
> >>> markchars-confusables.
> >>
> >> Neither would work AFAICS, because these characters are glyphless. 
> >> Highlighting a glyphless character will not make it more visible.
> >
> > ??? Of course, it will make it more visible: if the face has a distinct 
> > background.  The "thin space" display looks like whitespace, and 
> > whitespace can have background color to make it stand out.
> >
> 
> I tried various of the predefined colors with highlight-regexp, of course 
> those with a distinct background, and none make any of those characters 
> more visible.  Not even with a single pixel wide bar.

That's very strange, because I see them even if I make the region span
only a single such character.  The default background of the region
face is quite pale, and still I see them quite clearly, even with the
default light theme.