John Wiegley <jwiegley@gmail.com> writes:

> Since pattern matching like this isn't something I had ever encountered
> outside of FP, I agree that a tutorial is in order. I'm willing to
> volunteer
> for this.

I had already posted a tutorial here some time ago.  Sorry, my fault, I
did not yet find the time to further improve it and work in the
comments.

Here it is again: