Parsing Expression Grammars For Lua
$ luarocks install lpeg
LPeg is a new pattern-matching library for Lua, based on Parsing
Expression Grammars (PEGs). The nice thing about PEGs is that it
has a formal basis (instead of being an ad-hoc set of features),
allows an efficient and simple implementation, and does most things
we expect from a pattern-matching library (and more, as we can
define entire grammars).