LuaTeX is an extended version of pdfTeX using Lua as an embedded scripting language.
ConTeXt is a document processing system based on TeX.
This is a short how-to on how to embed Lua code into TeX.
\starttext
Hello World
\startluacode
-- A lua comment
tex.print("This is printed.")
local t = {1,2,3,4}
tex.print("length " .. #t)
\stopluacode
\ctxlua
{local t = {1,2,3,4}
tex.print("length " .. \string#t)}
\stoptext
Compile(!) the .tex
file:
$ texexec --luatex hello
You can open hello.pdf
to see the results, which should be:
Hello World
length 4