Simon Peyton-Jones (creator of Haskell) has released his 1987 book The Implementation of Functional Programming Languages for free online. Though it is 25 years old, it’s still considered an essential book on the topic of compilers for functional languages.
I’ve always had a soft spot for compilers and language design. They’re a fun, intricate design space. Though I haven’t read this book, it comes highly recommended. Have you read it? What were your impressions?