[luatex] void box

[Paul Isambert]

Andreas Matthias <andreas.matthias at gmail.com> a écrit:
> 
> What is the lua equivalent of a void box? I.e. how to
> create a void box in lua?

I'm not sure that it can be done, strictly speaking. By a void box, I
suppose you mean an unassigned box register (i.e. \voidb at x); now that
I think of it, it is strange that \unhbox\voidb at x is allowed in the
first place (if nothing is assigned to the register, how can you unhbox
it?).

On the Lua side, an unassigned box register (e.g. tex.box["voidb at x"])
returns nil (unlike an unassigned count register, which returns 0), so
I'd say the Lua equivalent of a void box is nil. Of course, if you're
just looking for an empty box, that's easy (except you have to specify
if it's an horizontal or vertical box): node.new(node.id"hlist", 2) or
node.new(node.id"vlist", 2) (the second argument is optional but later
it might be useful to know that this is a handmade box).

Best,
Paul