Paul Isambert <[email protected]> wrote: > Andreas Matthias <[email protected]> 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@x); now that > I think of it, it is strange that \unhbox\voidb@x is allowed in the > first place (if nothing is assigned to the register, how can you unhbox > it?).
what do you mean by "unassigned"? of course, without macros of some sort, \voidb@x won't be assigned (i.e., the name won't mean anything). i've not looked at context, but both plain and latex execute \newbox \voidb@x, but in both cases they only ever use it -- so nothing has been put into the virgin box. does luatex not actually allocate a register until its first use? if not, it will have to allocate \voidb@x pretty often, in two of the "big three" formats i know of. robin the un-knowledgeable
