[luatex] Info on direction primitives/implementation

[Arthur Reutenauer]

>               So I'm keen to find an answer that covers LuaTeX
> 'directly', if at all possible.

  You know, if I knew how to answer exactly that, I would just tell you :-)
I played a lot with Omega's typesetting directions back in the time; not
so much with LuaTeX, so I'm not sure how it works now, much less how it
is implemented.  I suppose your best bet is to get Taco to point you to
the relevant bits of the code, or have a look yourself.

	Arthur