The presentation is designed to pull you off the ground, to a higher order programming style, using the state and maybe monad as stepping stones. It finishes with stateful lifting.
Here is a link to a slightly improved version: youtube .
Link to sources are below but I would recommend that if you really do not know this type of programming and want to learn, then you should type it back in and allow yourself some creative liberty. This is usually a much better way to learn, than to just copy code!
You can watch it here if you want: