Subject: bug#77381: [PATCH] extend tex--prettify-symbols-alist

From: "Paul D. Nelson" <[email-masked]>
Date: Sun, 30 Mar 2025 15:27:05 +0200

>> This patch adds symbols to tex--prettify-symbols-alist.  The new symbols
>> include math symbols, accented characters, quotes and fractions.
>
> Thanks, but did you make sure this won't cause any regressions and/or
> annoyances if the user's machine doesn't have the requisite fonts
> installed?

If I understand correctly, the concern is that if a font for a character
in the alist is unavailable, Emacs will display a white square.  For
instance, on my machine (running macOS), adding

  (add-to-list 'prettify-symbols-alist '("\\satellite" . #x1F6F0))

makes "\satellite" look like a white square when prettify-symbols-mode
is active.

So the question is whether the symbols introduced by this patch are more
likely to cause such issues than those already in
tex--prettify-symbols-alist.

Using (set-face-attribute 'default nil :font "...") and C-u C-x =, I
checked that DejaVu Sans supplies all the new symbols except those
attached to

  \bigsqcup, \biguplus, "\ "

which are found in DejaVu Math TeX Gyre.

I checked that Arial has all the new symbols except those attached to

- \frac{1}{7}, \frac{1}{9}, \frac{1}{10}, \Game, found in DejaVu Sans
  (like for \daleth).

- \Finv, found in American Typewriter (like for \cdot), and

- \bigodot, \bigoplus, \bigotimes, \bigsqcup, \biguplus, \iiiint, found
  in DejaVu Math TeX Gyre.

Helvetica lacks many of the newly added and already present symbols.

This was a spot check, but it suggests that the new entries have similar
fallback behavior to existing ones, with the exception of a few
characters that depend on DejaVu Math TeX Gyre.

Perhaps the simplest way to avoid regressions would be to drop those
less well-supported symbols?