Re: colour plain tex keywords

[michael-franzese]

Have put the following code but it is not working for me.
What could be wrong?


(defun insert-ptex ()
  (interactive)
  (insert "ptex"))

(defvar ptex-mode-map
  (let ((map (make-keymap)))
    (define-key map (kbd "C-c t") 'insert-ptex)
    map)
  "Key map for use when variable `ptex-mode' is non-nil.")

(defvar ptex-mode-hook nil
  "Hook called when variable `ptex-mode' is non-nil.")

(define-minor-mode ptex-mode
  "Minor mode for colouring plain tex keywords."
  :init-value nil
  :global nil
  :lighter " ptex"
  :keymap ptex-mode-map
  (run-hooks 'ptex-mode-hook))

(add-hook 'texinfo-mode-hook 'ptex-mode)

(defface colour-greek-category
  '((default :inherit bold)
    (((class color) (min-colors 88) (background light))
     :foreground "#00FFFF")
    (((class color) (min-colors 88) (background dark))
     :foreground "#00FFFF")
    (t :inherit font-lock-builtin-face))
  "Face for greek category keywords.")

(defconst ptex-greek-keywords
  '(("\\\\\\<\\(alpha\\|beta\\|gamma\\)\\>"
     (1 'colour-greek-category)))
  "Rules to apply font-lock highlighting.")

(defun ptex-assign-font-greek-keywords ()
  "Font-lock setup for `ptex-greek-keywords'."
  (font-lock-flush (point-min) (point-max))
  (if ptex-mode
      (font-lock-add-keywords nil ptex-greek-keywords t)
    (font-lock-remove-keywords nil ptex-greek-keywords))
  (font-lock-flush (point-min) (point-max)))

 (add-hook 'texinfo-mode-hook #'ptex-assign-font-greek-keywords)

(provide 'ptex-mode)




> Sent: Tuesday, January 12, 2021 at 12:05 PM
> From: "Emanuel Berg via Users list for the GNU Emacs text editor" 
> <help-gnu-emacs@gnu.org>
> To: help-gnu-emacs@gnu.org
> Subject: Re: colour plain tex keywords
>
> michael-franzese wrote:
>
> > How can I associate the actual keywords wtih the face, so
> > I can highlight the lower case greek letter commands in
> > plain tex.
>
> You can use `font-lock-add-keywords'. That doesn't always
> work tho, why I don't know.
>
> But here is an example where it works:
>
>   https://dataswamp.org/~incal/figures/emacs/dressed-up-as-themselves.png
>
> --
> underground experts united
> http://user.it.uu.se/~embe8573
> https://dataswamp.org/~incal
>
>
>