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Better-looking Verbatim Markup in Org Mode

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Org mode has two verbatim markups: ~code~ and =verbatim=. I think Markdown’s `code` looks better as backticks are smaller, thus more unobtrusive when in body text and tables. I made ~ and = in Org Mode to display as `, the result looks pretty good:

demo.png

New method (<2020-07-23 Thu>)

The old method has some problems including 1) delimiters disappear for unknown reason, and 2) we need to redefine Org Mode’s function. Here is a new method that solves both problems.

Basically we add another function to jit-lock-functions which runs after Org Mode has fontified the buffer text. Then we make any ~ and = character that has org-code face or org-verbatim face to display ` instead.

To enabled it just add org-backtick-mode to org-mdoe-hook.

(defun org-backtick-fontify (beg end)
  "Fontify ~ and = between BEG and END."
  (goto-char beg)
  (while (re-search-forward (rx (or "~" "=")) end t)
    (let* ((text-props (text-properties-at (match-beginning 0)))
           (face (plist-get text-props 'face)))
      ;; Make it display backtick if the face indicates that
      ;; it’s a code/verbatim delimiter.
      (if (or (equal face '(org-code))
              (equal face '(org-verbatim)))
          (put-text-property
           (match-beginning 0) (match-end 0) 'display "`")
        ;; Clean up our face if it’s not a code/verbatim
        ;; delimiter anymore.
        (when (equal (plist-get text-props 'display) "`")
          (put-text-property
           (match-beginning 0) (match-end 0) 'display nil)))))
  (cons 'jit-lock-bounds (cons beg end)))

(define-minor-mode org-backtick-mode
  "Display ~ and = as backticks."
  :lighter ""
  (if org-backtick-mode
      ;; We want to run after org-mode’s font-lock function.
      (add-hook 'jit-lock-functions #'org-backtick-fontify 91 t)
    (remove-hook 'jit-lock-functions #'org-backtick-fontify t))
  (jit-lock-refontify))

Old method

The idea is to add an display text property to the markers when fontifying them. First, in org-emphasis-alist, I added an extra fourth entry for ~ and =: the text property we will add to ~ and = in fontification function.

("=" org-verbatim verbatim (display "`"))
("~" org-code verbatim (display "`"))

Sadly, there is no opportunity for hooks or advising the fontification function, I had to redefine org-do-emphasis-faces. Towards the end of the function, we first change the pcase form to extract our extra entry added earlier, we change

(pcase-let ((`(,_ ,face ,_) (assoc marker org-emphasis-alist)))
  ...)

to

(pcase-let ((`(,_ ,face ,_ ,props) (assoc marker org-emphasis-alist)))
  ...)

Then, before

(when org-hide-emphasis-markers
  (add-text-properties (match-end 4) (match-beginning 5)
                       '(invisible org-link))
  (add-text-properties (match-beginning 3) (match-end 3)
                       '(invisible org-link)))

we add

(when props
  (add-text-properties (match-end 4) (match-beginning 5)
                       props)
  (add-text-properties (match-beginning 3) (match-end 3)
                       props))

“Wait”, you may ask, “why not use org-hide-emphasis-markers?” You can try, and you will regret it. The invisible markers make editing text around them a nightmare.

Finally, here is the full code:

(with-eval-after-load 'org
  (setq org-emphasis-alist
        '(("*" bold)
          ("/" italic)
          ("_" underline)
          ("=" org-verbatim verbatim (display "`"))
          ("~" org-code verbatim (display "`"))
          ("+"
           (:strike-through t))))

  (defun org-do-emphasis-faces (limit)
    "Run through the buffer and emphasize strings."
    (let ((quick-re (format "\\([%s]\\|^\\)\\([~=*/_+]\\)"
                            (car org-emphasis-regexp-components))))
      (catch :exit
        (while (re-search-forward quick-re limit t)
          (let* ((marker (match-string 2))
                 (verbatim? (member marker '("~" "="))))
            (when (save-excursion
                    (goto-char (match-beginning 0))
                    (and
                     ;; Do not match table hlines.
                     (not (and (equal marker "+")
                               (org-match-line
                                "[ \t]*\\(|[-+]+|?\\|\\+[-+]+\\+\\)[ \t]*$")))
                     ;; Do not match headline stars.  Do not consider
                     ;; stars of a headline as closing marker for bold
                     ;; markup either.
                     (not (and (equal marker "*")
                               (save-excursion
                                 (forward-char)
                                 (skip-chars-backward "*")
                                 (looking-at-p org-outline-regexp-bol))))
                     ;; Match full emphasis markup regexp.
                     (looking-at (if verbatim? org-verbatim-re org-emph-re))
                     ;; Do not span over paragraph boundaries.
                     (not (string-match-p org-element-paragraph-separate
                                          (match-string 2)))
                     ;; Do not span over cells in table rows.
                     (not (and (save-match-data (org-match-line "[ \t]*|"))
                               (string-match-p "|" (match-string 4))))))
              ;; beg
              (pcase-let ((`(,_ ,face ,_ ,props) (assoc marker org-emphasis-alist)))
                ;; end
                (font-lock-prepend-text-property
                 (match-beginning 2) (match-end 2) 'face face)
                (when verbatim?
                  (org-remove-flyspell-overlays-in
                   (match-beginning 0) (match-end 0))
                  (remove-text-properties (match-beginning 2) (match-end 2)
                                          '(display t invisible t intangible t)))
                (add-text-properties (match-beginning 2) (match-end 2)
                                     '(font-lock-multiline t org-emphasis t))
                ;; beg
                (when props
                  (add-text-properties (match-end 4) (match-beginning 5)
                                       props)
                  (add-text-properties (match-beginning 3) (match-end 3)
                                       props))
                ;; end
                (when org-hide-emphasis-markers
                  (add-text-properties (match-end 4) (match-beginning 5)
                                       '(invisible org-link))
                  (add-text-properties (match-beginning 3) (match-end 3)
                                       '(invisible org-link)))
                (throw :exit t)))))))))

Written by Yuan Fu

First Published on 2020-07-07 Tue 21:38

Last modified on 2020-09-12 Sat 16:10

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