[plt-scheme] Can you study HTDP to satisfy the goal to learn Functional Programming?

> Unfortunately, I can't recommend just one book for this purpose.  Over
> the years, I've read a large number of books written in a variety of
> languages, and most books have one or two large programs to study, so
> for me it's been more of a cumulative process.

What are some of your favorites?

> Of the books I've read
> most recently, the new Erlang book comes to mind as having a couple
> good extended examples of FP in action.

What were some of your take-aways from this book?