- Maybe LALR is the wrong way to go, what about this?
    http://boshi.inimino.org/3box/asof/1269629763069/PEG/ECMAScript_unified.peg

- List of parsers here:
    https://github.com/joyent/node/wiki/modules#parser-generators

- Try perhaps uglify  / burrito:
  - https://github.com/mishoo/UglifyJS
  - https://github.com/mishoo/UglifyJS/blob/6a873a7757895fdc06501854e4ba84e15c12a74a/tmp/instrument.js
  - https://github.com/substack/node-burrito