[luatex] Luatex primitive names

[Arthur Reutenauer]

> At some point in this discussion I will start screaming, I am sure ;)

  The devil lies in the details :-)

> I believe that in the combination of \luatexversion + \directlua
> would be a better choice than yet another primitive name, but no,
> the --ini primitive does not have to be called \directla per se.
> It could be called \luatexdirectlua or so.

  That was my point.  I'm not saying it was a particularily good one.

> In any case, \directlua will remain present in the 'luatex' block of
> primitives because of all the exposure it has gotten already; but
> also because it nicely complements \latelua (which \luadirect doesnt).

  Sure enough.  I guess we could rule that \directlua per se
characterizes LuaTeX well enough, and that XeTeX, or any other
extension that would add Lua to the TeX engine, should use some other
name.  As I pointed out, the Lua interpreter inside XeTeX would be
significantly different from what we have currently in LuaTeX.  For that
matter, I'm not even sure if a difference between immediate and late
execution of Lua would be relevant outside of LuaTeX.

	Arthur