The book is using processing itself (a Java DSL afaik) but there are example repos at github using JS or clojure. It's easy to translate processing to quil, they share almost the same API.
Do you have previous experience in Processing @thsojka? I don't know if I could have gotten Quil without previous years of Processing experience. My long, tedious process includes typing in the original Processing code, so I can see that Quil draws the same things.
Hmm I think I read some p5.js tutorials about a year ago, otherwise starting with natureofcode about half a year ago was my start with processing
I've been making some nice progress I think on my quil/processing experiments
the images in each tweet are all from the same code
the second tweet had some small tweaks to the code from the first one