[TeX] Switch mono font to JuliaMono and Emoji font

[inkydragon]

Related issue: #803

There are still many Unicode symbols that cannot be displayed in the DejaVu Sans Mono font.
According to tests, JuliaMono is currently the best choice.

⊼ ⊽ ⊻ ≡ ≤ ⧐
ℯ π ௰ ℵ Θ α β
⛵ 🚀
⋮ ⠀ ⠈ ⡀ ⠁ ⠠
∤ ⅋ ≀ ⊼ ⋇ ⋉ ⋊ ⋋ ⋌ ⋒ ⟑ ⦸ ⦼ ⦾ ⦿ ⧶ ⧷ ⨇ ⨰ ⨱ ⨲ ⨳ ⨴ ⨵ ⨶ ⨷ ⨸ ⨻ ⨼ ⨽ ⩀ ⩃ ⩄ ⩋ ⩍ ⩎ ⩑ ⩓ ⩕
⩘ ⩚ ⩜ ⩞ ⩟ ⩠ ⫛ ⨝ ⟕ ⟖ ⟗ ∔ ⊽ ⋓ ⨈ ⨢ ⨣ ⨤ ⨥ ⨦ ⨧ ⨨ ⨩ ⨪ ⨫ ⨬ ⨭ ⨮ ⨹ ⨺ ⩁ ⩂ ⩅ ⩊ ⩌ ⩏ ⩐ ⩒ ⩔ ⩖ ⩗ ⩛ ⩝ ⩡ ⩢ ⩣

DejaVu Sans Mono vs. JuliaMono Result

Self-contained TeX test case: minted-math-sym

Note: JuliaMono don't support emoji.

Font comparators: Monospace fonts for math

[mortenpi]

I think it would be awesome to use JuliaMono in the PDF. Are there any technical difficulties with switching it over.

As for symbols (including emojis) not supported by JuliaMono -- how doable you think would be a fallback to DejaVu Sans Mono in those cases? We have a fallback hack for one symbol:

Documenter.jl/assets/latex/documenter.sty

Lines 7 to 11 in cd49b07

	% DejaVu Sans Mono does not have the xor symbol. So we hack around that by replacing all
	% instances of it with calls to \unicodeveebar, which prints this single character as with
	% DejaVu Sans instead.
	\newfontfamily\unicodeveebarfont{DejaVu Sans}[Scale=MatchLowercase]
	\newcommand\unicodeveebar{{\unicodeveebarfont ⊻}}

But I am not sure how feasible it would be to it for a whole big set of symbols.

[inkydragon]

Are there any technical difficulties with switching it over.

As of now, no.

diff --git a/documenter.sty b/documenter.sty     
index 1bccfff..ace21d9 100644
--- a/documenter.sty
+++ b/documenter.sty
@@ -2,13 +2,9 @@
 \usepackage{fontspec, newunicodechar, polyglossia}
 
 \setsansfont{DejaVu Sans}[Scale=MatchLowercase, Ligatures=TeX]
-\setmonofont{DejaVu Sans Mono}[Scale=MatchLowercase]
+\setmonofont{JuliaMono Regular}[Scale=MatchLowercase]
+\newcommand\unicodeveebar{ ⊻ }
 \renewcommand{\familydefault}{\sfdefault}
-% DejaVu Sans Mono does not have the xor symbol. So we hack around that by replacing all
-% instances of it with calls to \unicodeveebar, which prints this single character as with
-% DejaVu Sans instead.
-\newfontfamily\unicodeveebarfont{DejaVu Sans}[Scale=MatchLowercase]
-\newcommand\unicodeveebar{{\unicodeveebarfont ⊻}}
 %

---

how doable you think would be a fallback to DejaVu Sans Mono in those cases?

First, let's be clear that we cannot expect one font to be used in all scenarios.

After some exploration, I found that we probably need at least 5 kinds of fonts.

• Choosing JuliaMono as the mono font is at least as good as the DejaVu Sans Mono currently in use
• We need Chinese and Korean fonts: CJK
• emoji needs new fonts: Emoji font; May needs to switch to use lualatex.
• Mathematical symbols require careful font selection, to be explored further: Math font, unimath-symbols.pdf;
  Some tests: source code unicode-table/math-sym; font comparison results PDFs

[mortenpi]

It would also be necessary to make the Julia Mono font files available to the user somehow. And the same applies to other fonts not easily available in Linux distros. But I think we can bake them into the Docker image.

May needs to switch to use lualatex.

I believe we already build with LuaTex, as we pass -lualatex to latexmk?

[cormullion]

As for symbols (including emojis) not supported by JuliaMono

I'm currently preparing another release of JuliaMono, so if there are any additional Unicode characters you need me to add, now's a good time to add them. (Emojis, though, are usually handled by the OS, and I'm more than happy to not do any of them.😀)

[ViralBShah]

Should we transition Documenter.jl to default to JuliaMono?

[cormullion]

I don't know LaTeX, but does this address the emoji/font switching issue:

https://github.com/Pomax/ucharclasses

[inkydragon]

emoji/font switching issue

I choose \usepackage{emoji}.
And I'm looking for a good emoji font.
Some choices: https://github.com/inkydragon/Julia-LaTeX-doc/blob/master/LaTeX-issues/unicode-table/memo.md

[cormullion]

fonts provided through google-fonts (Noto) probably safer in terms of support and maintenance