You can find the slides, for this workshop, at https://speakerdeck.com/chrispitt/implementing-languages-fluentconf.

Install Babel compiler (to make ES6 work!):

$ npm install --save-dev babel-cli

Then, run each script to see output:

$ babel-node lexer.js

Alternatively, you can run this code in https://jsbin.com/ after setting the JavaScript dropdown to "ES6 / Babel".

Feel free to leave feedback at http://conferences.oreilly.com/fluent/javascript-html-us/public/schedule/detail/46342.