I was so excited for this, then I realized it uses C (which I'm not familiar with).
Also, all of the code in the book has been ported to a large number of languages:
https://github.com/munificent/craftinginterpreters/wiki/Lox-...
But his C is so clean. Is readable as far as is possible, imho.
Plus, exist some many implementations of this in as languages are, so you can go along (https://github.com/search?q=crafting+interpreters or using https://github.com/search?q=lox+interpreter).