[silentbicycle]

You might find the way that closures ("upvalues") are implemented in Lua helpful, too. There's a summary in this paper (http://www.tecgraf.puc-rio.br/~lhf/ftp/doc/jucs05.pdf) starting around pg. 8, and the source (http://www.lua.org/source/5.1/) is pretty readable (if somewhat sparsely commented).