[Dev-luatex] Some questions

[Jonathan Sauer]

Hello,

thanks for your quick reply!

> [...]
> > - How do I generate an error when inside Lua code? I could use
> >   tex.write("\\errmessage{...}"), but then the error would only be
> >   generated after the Lua code has finished executing, and after
> >   any TeX code created previously using tex.write et.al. has
> >   been executed.
> 
> - assert
> - just print messages using texio.write_nl
> - os.exit() also works

The last one is a bit radical ;-)

I was hoping to be able to say i.e. "error(message,help)" and get TeX's
error prompt where the user can decide how to proceed.

> > - How do I access control sequences from Lua code? If I have a
> >   macro \test, how would I get the tokens of this macro when inside
> >   Lua? (without passing them from TeX) Is there a table tex.macro,
> >   just like the tex.count, tex.toks etc. tables?
> 
> no, you print them to tex using tex.print and tex.sprint; 
> you're either is lua or in tex; something in between would 
> become extremely messy

But what about the other way round? What if I do not want to define
control sequences, but access their meaning from Lua code, just as
it is possible with registers? Is there a way?


Jonathan