Integrate tex2mn into MN

[paolobrasolin]

I submitted the package to CTAN and set up a GHA action to release new tags on both GH and CTAN automatically.

---

In essence, tex2mn is composed of

• metanorma.cls which is a LaTeX class to directly compile standard documents from tex to pdf. We don't strictly need it for MN, but it's nice for the user to have.
• metanorma.cls.ltxml which is a latexml script which allows transpiling tex to an intermediate xml representation
• metanorma.xsl which is a latexmlpost stylesheet which allows transpiling the intermediate xml representation to Metanorma's adoc

Running tex2mn is a two step job:

latexml input.tex  --destination=intermediate.xml --preload=metanorma.cls --nocomments --strict
latexmlpost intermediate.xml --destination=output.adoc --stylesheet=metanorma.xsl --nocrossref --nodefaultresources
# NOTE: latexml is actually prealoading metanorma.cls.ltxml, which is in the same folder as metanorma.cls

In case the workflow benefits from it, these commands also work piping stdin/stdout:

cat input.tex \
  | latexml - --preload=metanorma.cls --nocomments --strict \
  | latexmlpost - --stylesheet=metanorma.xsl --nocrossref --nodefaultresources |
  > output.adoc

All the flags are needed as they are because of technical reasons (not delving into that here).

The exceptions are:

• --preload=metanorma.cls: if tex2mn (i.e. the metanorma CTAN package) is installed correctly, this flag can be omitted, as latexml can automatically solve the dependency
• --stylesheet=metanorma.xsl: even if tex2mn (i.e. the metanorma CTAN package) is installed correctly, this flag cannot be omitted, but it can be simplified leveraging TeX's path resolver by writing --stylesheet=$(kpsewhich metanorma.xsl)

All that said, the piece of pipeline which is missing from MN

• is TEX -> ADOC
• is equivalent to the combination of the two commands above
• requires the presence of latexml and latexmlpost (pretty common in LaTeX distributions)
• requires the presence of tex2mn (i.e. the metanorma CTAN package) either properly installed or put in a known folder

CAVEAT: we need an unreleased feature of latexml, contained precisely in git://github.com/brucemiller/LaTeXML.git@9a0e7dc5 Installation details for common OSs are available in the workflows: https://github.com/metanorma/tex2mn/tree/master/.github/workflows We'll have to wait for LaTeXML 0.8.5 to avoid handpicking a commit -- it's expected by July 2020: https://github.com/brucemiller/LaTeXML/issues/1234#issuecomment-591046589 Here is the progress status: https://github.com/brucemiller/LaTeXML/milestone/12

[ronaldtse]

@paolobrasolin thank you for this great news!

Could you help with:

1. Provide setup instructions regarding CTAN and the metanorma.xsl stylesheet
2. Update https://github.com/metanorma/mn-samples-tex-iso to reflect changes (and update its code to the latest mn-samples-iso)
3. Update https://github.com/metanorma/rfc-camelot-holy-grenade-tex to make sure it is compilable
4. Explain to @opoudjis on how to provide "TEX -> ADOC" flow inside the Metanorma gems (e.g. metanorma-tex gem or tex2mn gem?)

For the handpicked LaTeXML, @CAMOBAP can you help release that version in Snap as "edge" for now? Thanks!

[CAMOBAP]

@ronaldtse @paolobrasolin we already did --edge release for snap for git://github.com/brucemiller/LaTeXML.git@9a0e7dc5

Please let me know if we should do the same for chocolatey

P.S. for OSX we don't control brew package, but it can be easily installed like this https://github.com/metanorma/metanorma-standoc/blob/master/.github/workflows/macos.yml#L30-L32

[CAMOBAP]

ping @ronaldtse @paolobrasolin

[ronaldtse]

Thanks @CAMOBAP ! Yes, can you please do the same for chocolatey, and can you also write up some documentation on metanorma.com on how to install this special version of LaTeXML for Metanorma on different platforms?

[CAMOBAP]

@ronaldtse done https://github.com/metanorma/metanorma.com/pull/263

[CAMOBAP]

Done