Re: New line and trailing whitespaces

[Ergus]

On Tue, Apr 23, 2024 at 07:19:02PM GMT, Eli Zaretskii wrote:
> > Date: Tue, 23 Apr 2024 17:38:15 +0200
> > From: Ergus <spacibba@aol.com>
> > Cc: help-gnu-emacs@gnu.org
> >
> > >You need to customize whitespace-display-mappings.  Specifically, the
> > >tab-mark element of the value is by default the vector '[?� ?\t], and
> > >you need to replace each of these two characters with a glyph that has
> > >the face you want, using make-glyph-code.  Caveat: a comment in
> > >whitespace.el explains why only newlines are given a face:
> > >
> > >          ;; Only insert face bits on NEWLINE char mapping to avoid
> > >          ;; obstruction of other faces like TABs and (HARD) SPACEs
> > >          ;; faces, font-lock faces, etc.
> > >
> >
> > Ahh this is exactly what I want..
> >
> > Do you think it worth adding your paragraph as a comment somewhere in
> > whitespace or reference that in its manual section?
>
> IMO, if we want users to be able to do this, we need a more
> user-friendly way of doing that.  Like define a special face, and make
> whitespace.el use make-glyph-code with that face, given some user
> option setting.
>
> Patches welcome.
Hi Eli:

I tried this.

(with-eval-after-load 'whitespace
  (setq whitespace-style '(faces tab-mark)
        whitespace-display-mappings `((tab-mark ?\t [,(make-glyph-code ?� 
'whitespace-tab) ?\t] ))
        ))
(whitespace-mode 1)

But I only get the error:

wrong-type-argument number-or-marker-p (187 . 235)

Some idea what I am doing wrong?

Best,
Ergus