Org: Julia code blocks in LaTeX

We need to do a little finangling to get this working nicely.
For unicode, we need to switch to LuaLaTeX (I tried XeLaTeX but it
didn't seem happy for some reason), and then adjust microtype to remove
the pdfLaTeX-only flags.

config.org

@@ -7992,6 +7992,49 @@ Treating the verbatim (no syntax highlighting) result as a baseline; this
 rudimentary test suggest that =engrave-faces= is around eight times faster than
 =pygments=, and takes three times as long as no syntax highlighting (verbatim).
 
+**** Julia code blocks
+
+Julia code has fantastic support for unicode! The downside is that =pdflatex= is
+/still/ a pain to use with unicode symbols. The solution --- =lualatex=. Now we just
+need to make it automatic
+
+#+begin_src emacs-lisp
+(defadvice! org-latex-pick-compiler (_contents info)
+  :before #'org-latex-template
+  (when (and org-export-has-code-p (memq 'julia-code (org-latex-detect-features)))
+    (setf info (plist-put
+                (if (member #'+org-latex-replace-non-ascii-chars (plist-get info :filter-final-output))
+                    (plist-put info :filter-final-output
+                               (delq #'+org-latex-replace-non-ascii-chars (plist-get info :filter-final-output)))
+                  info)
+                :latex-compiler "lualatex"))))
+#+end_src
+
+Then a font with unicode support must be used. JuliaMono is the obvious choice,
+and we can use it with the =fontspec= package. In future it may be nice to set
+this just as a fallback font (when it isn't a pain to do so).
+
+#+name: julia-mono-fontspec
+#+begin_src LaTeX
+\\usepackage{fontspec}
+\\newfontfamily\\JuliaMono{JuliaMono-Regular.ttf}[Path=/usr/share/fonts/truetype/, Extension=.ttf]
+\\newfontface\\JuliaMonoRegular{JuliaMono-Regular}
+\\setmonofont{JuliaMonoRegular}[Contextuals=Alternate, Scale=MatchLowercase]
+#+end_src
+
+Now all that remains is to hook this into the preamble generation.
+
+#+begin_src emacs-lisp :noweb no-export
+(setq org-latex-julia-mono-fontspec "
+<<julia-mono-fontspec>>
+")
+
+(add-to-list 'org-latex-feature-implementations '(julia-code :snippet org-latex-julia-mono-fontspec :order 2) t)
+(add-to-list 'org-latex-conditional-features '((and org-export-has-code-p "^[ \t]*#\\+begin_src julia\\|^[ \t]*#\\+BEGIN_SRC julia\\|src_julia") . julia-code) t)
+
+(add-to-list 'org-latex-feature-implementations '(!microtype-lualatex :when (microtype julia-code) :prevents microtype :snippet "\\usepackage[activate={true,nocompatibility},final,tracking=true,factor=2000]{microtype}\n"))
+#+end_src
+
 **** Remove non-ascii chars
 
 When using ~pdflatex~, almost non-ascii characters are generally problematic, and

misc/config-publishing/org-pdf.sh

@@ -29,6 +29,10 @@
     (insert (shell-command-to-string (expand-file-name "./gen-org-snippets.sh" script-root)))
     (message "[33] Exporting %s" (buffer-file-name))
     (org-mode)
+    ;; There isn't actually any Julia code in config.org
+    (setq org-latex-conditional-features
+          (delq (rassq 'julia-code org-latex-conditional-features)
+                org-latex-conditional-features))
     (org-latex-export-to-pdf)))
 
 (publish "config.pdf")