Pandoc: Selectively disable typographic ligatures in LuaLaTeX

[fkohrt]

English and German introductions to typography mention that some words must not contain ligatures at certain points, such as

• shelfful
• Kaufleute

(illegal ligature in strong emphasis)

In LaTeX, one would either have to manually disable them with \kern0pt or \hspace{0pt}(such as shelf{\kern0pt}ful), or use microtype to disable them globally.

However, there's a LuaLaTeX package that does this automatically for an included selection of words: selnolig. According to selnolig's documentation, it has to be loaded after the babel package. Therefore, just using header-includes is not feasible, as that's located before.

Hence I suggest loading the selnolig package in case the LuaLaTeX engine is used, probably somewhere after line 341 of the LaTeX template:

--- pandoc-templates/default.latex  2020-07-15 00:28:58.124000000 +0200
+++ -   2020-07-15 00:31:00.189391730 +0200
@@ -339,6 +339,9 @@
 $endif$
 \fi
 $endif$
+\ifluatex
+  \usepackage{selnolig}
+\fi
 $if(dir)$
 \ifxetex
   % Load bidi as late as possible as it modifies e.g. graphicx

[mb21]

you can probably use a custom template?

[fkohrt]

Oh yeah, I'm doing that. But I thought this might improve the default template; in a similar way everybody could load microtype themself, but instead it's been added to the default template.

[jgm]

My only worry here is about depending on packages that aren't widely available. We try to stick with the most common ones so the default template will work with a more minimal install.

[jgm]

Still, I think this is probably a good idea.

[jgm]

I tried this. Maybe I'm doing it wrong, but I can't see any difference in the output (e.g. for Auflage in German). I still see a ligature.

[fkohrt]

Maybe you haven't set the language?

Running pandoc --standalone --from=markdown --to=latex --pdf-engine=lualatex --output=with-selnolig.pdf --template=default.latex test.md on the patched default.latex and the following test.md works for me:

---
title: Test
lang: de
---

Auflage

Compare this with pandoc --standalone --from=markdown --to=latex --pdf-engine=lualatex --output=without-selnolig.pdf test.md

[jgm]

I did set lang. But I forgot to specify lualatex!

[fkohrt]

Shouldn't the selnolig package be also mentioned in the MANUAL, now that it's used in the template?

[jgm]

Good thought, I added something.