textproc/R-cran-tth: New port: Convert TeX/LaTeX to HTML/MathML

[uzsolt]

Summary

C source code and R wrappers for the tth/ttm TeX-to-HTML/MathML translators.

The R package tth ships the C sources for convenient compilation and
installation on all platforms.
It also provides wrappers in R to process R character vectors with the command
line tools directly from the R prompt.

The textproc/tth port ships `tth' binary but the two sources differ.
The `ttm' binary isn't available in the ports tree.

Approved by: bofh (mentor) OR diizzy (mentor)
(Differential Revision: https://reviews.freebsd.org/D###)

Test Plan

Portlint, portclippy, portfmt passed.
Poudriere testport passed (13.2, 13.3, 14.0).
The example in pdf documentation (https://cran.r-project.org/web/packages/tth/tth.pdf)
passed.

This package is suggested by R-cran-exams (plan to add to ports tree, https://www.r-exams.org/),
and the ttm converter is better than pandoc for mathematical formulas:
ttm generates MathML which is supported all major browsers (Chrome too!), the
pandoc generates a small image.

[diizzy]

See note about for loop in post-install section

textproc/R-cran-tth/Makefile

16

A style preference but try to avoid loops if possible unless it makes sense.
In this case you're adding more lines (3 vs 2) than without so I'd say skip it.