[luatex] Translating TeX (obviously a feature request).

[Paul Isambert]

Hello all,

Since LuaTeX reaches down to TeX's most intimate parts (its bowels, of course),
I was wondering whether there is any plan to give access to TeX's messages, e.g.
error messages or box reporting, and modify them. My idea is that it may be
interesting to have versions of TeX that speak any language, because those
messages could be written as one wishes. I imagine a kind of callback-like
interface, for instance (probably in a configuration file):

tex.internal_error("undefined_cs","Commande non définie")

would replace TeX's "Undefined control sequence" by the French message. The
impact would be somewhat limited, since anyway most people using TeX speak
English (they can't really do otherwise), but wouldn't it be worth trying? That
would be in line with turning from ASCII to Unicode. I haven't the least idea of
what implementing TeX features takes, but this one seems easy to my ignorant
eyes... although I understand the LuaTeX already has much on its plate! (By the
way, thanks Taco for taking into account the write issue.)

Best,
Paul