[tex-hyphen] Customizing patterns

[Javier Bezos]

Hi all,

Hyphenation doesn't depend only of the language, but also
on the field (Chemistry has particular needs), the style
and, sometimes, the country (eg, in Spanish, the group tl is
-tl in México and t-l in Spain).

At request of a subscriber of es-tex (the mailing list of
Spanish TeX) I was investigating how to customize somehow
the patterns. With luatex it's trivial, but not so with
standard TeX. Now, with the suggestions and bugs from
Rodrigo, I'll give it a push forward.

I think the simplest way to carry out this is to provide
two "languages" -- namely, the standard (and default), with
the full set of usual patters, and a "local" set which can
be configured locally and selected with, say, an option in
babel or similar. There will be about 5 options and therefore
considering all combinations as separate "languages" is
impossible. But a single local file, so that the settings
are writen to the log file (for reference), could be feasible.
Let me say I'm still investigating how to do it, but perhaps
this system will be enough in most of cases.

Any thoughts?

Javier