Re: New line and trailing whitespaces

[Ergus <spacibba@aol.com>]

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