Re: Fallback fonts in LaTeX export for non latin scripts

[Ihor Radchenko]

Juan Manuel Macías <maciaschain@posteo.net> writes:

> These days I'm working on some experimental code to try to provide Org
> with some sort of fallbacks fonts on LaTeX export. The functionality
> would (for now) be linked to LuaTeX + babel package, since XeTeX,
> although it has the ucharclasses package, is more limited.

Thanks! That would be a welcome addition.

> The idea is to start from a defcustom that is an alist where each element
> has the structure (script font). There would also be a default script +
> font, for example ("latin" "Linux Libertine"). At the moment it would
> only work for the default roman font, but it can be extended to default
> sans serif, mono, etc.

Are the fonts you have in mind shipped with LuaTeX distribution?

> The functionality would not be activated by default. When activated, it
> also enables LuaTeX as the default LaTeX engine, and on each export a
> list of non-latin scripts in the buffer is extracted. Perhaps with
> some code like this, which checks for any non-latin characters:
>
> (let ((scripts))
>   (save-excursion
>     (goto-char (point-min))
>     (while
>         (re-search-forward "\\([^\u0000-\u007F\u0080-\u00FF\u0100-\u017F]\\)" 
> nil t)
>       (let ((script (aref char-script-table
>                           (string-to-char (match-string 1)))))
>         (add-to-list 'scripts script)
>         (setq script-list scripts))))
>   script-list)
>
> ?
>
> Once the list has been extracted, an ad hoc preamble would be formatted
> assigning each script the chosen font.
>
> WDYT? Do you think this would be a viable path? I think that in a few
> days I can offer something usable for discussion.

Adding Timothy to CC. His WIP conditional preamble branch looks suitable
to add the proposed functionality.

What will happen if LuaTeX is not installed on the system?

Also, just to double check, is LuaTeX fully compatible to LaTeX? That
is, if we have an existing org file using LaTeX-specific commands and
packages, will it work with LuaTeX?

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
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