This page has both links to purchase the book and a link to the free online version: https://craftinginterpreters.com/

This is definitely a book that's worth purchasing: The care that Nystrom put into the designing the physical copy is worth it by itself if you're a print nerd. The hand-drawn illustrations plus the excellent writing make this better than 99% of technical books.

This is one of the best technical books I have ever read. Having evolving code and a running program at the end of each chapter is an incredible vision, and props to the author for pulling it off. I skimmed the tree-walking interpreter as I'd written those before, then worked through the C-based bytecode interpreter and learned tonnes more.

Wow, I thought the article was recent and thought there was a second release.

I’d like to congratulate the author, this is not only a great source of technical depth in the real of languages, but also a great read as far as the layout and the small details in the graphics made is a source that I just keeps me engaged in the reading. I’s one of those books that feels will be relevant for many-many-years to come!

Congrats and thank you!

I started working through Crafting Interpreters back in 2017, and did the first half of the book (decided to write the lox implementation in Scala instead of Java), and it completely demystified tokenizers/lexers/parsers/interpreters for me. They were something I thought of as this arcane art that only a certain kind of programmer could work on. Absolutely credit this to Nystrom's brilliant writing and depth of understanding of the topic.

I started writing the second interpreter in Rust, but life intervened and I didn't get far, and didn't finish it. I think it's time to get back to it!

Though this post is a few years old, I hadn't known he decided to turn it into a physical book. That's not really the best way I learn, I don't think, but I'm tempted to buy one just to have it, and to support the author.

This is one of the best technical computer books I have ever read. Thoroughly, thoroughly enjoyed it and learned a whole lot from it.

And besides the great technical content, it is also well-written, funny, and well-illustrated. A monumental achievement!