nix-shell environment for [riddim](http://code.zash.se/riddim/)

default.nix

with import <nixpkgs> {}; {
  luaEnv = stdenv.mkDerivation {
    name = "lua";
    buildInputs = [ stdenv lua51Packages.luasocket lua51Packages.luaexpat lua51Packages.luasec ];
    LUA_PATH="${lua51Packages.luasec}/lib/lua/5.1/?.lua;${lua51Packages.luaexpat}/share/lua/5.1/?.lua;${lua51Packages.luasocket}/share/lua/5.\
1/?.lua;./?.lua";
    LUA_CPATH="${lua51Packages.luasec}/lib/lua/5.1/?.so;${lua51Packages.luaexpat}/lib/lua/5.1/?.so;${lua51Packages.luasocket}/lib/lua/5.1/?.s\
o;./?.so;/usr/lib/lua/5.1/?.so;/usr/lib/lua/5.1/loadall.so";
  };
}