The Lua users wiki is very helpful but I don't think there is any PDF
quick ref (http://lua-users.org/wiki/). And if you mean “Lua, as in Lua
used in LuaTeX" (with all the additional libraries, etc.), then no,
definitely no.
Arthur
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the
Wiki!
maillist : [email protected] / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://tex.aanhet.net
archive : https://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___________________________________________________________________________________