Re: Display of undisplayable characters: \U01F3A8 instead of diamond

[Eli Zaretskii]

> Date: Tue, 30 Aug 2022 14:41:49 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: emacs-devel@gnu.org
> 
> > Using several disjoint ranges could do the job, I suppose,
> > if someone can tell me how to determine what those ranges should be.
> > 
> > Could this be figured out automatically by calling char-displayable-p
> > on each character code?
> 
> Such a code can be written, and can use char-displayable-p, indeed.
> 
> > Up to what number would that loop have to run?
> 
> Up to (and including) #x10FFFF.

That's the theory, of course.  In practice, with the Linux console,
you could only run the loop till #xFFFF, I guess, and just assume the
rest of the characters are not displayable without checking.