It’s finished and ready to ship now. Buying Rust in Action it from the publisher is fastest. Amazon and other distributors do not yet have it in stock.
Good question! It is not a 700 page book covering the entire language. Expect light treatment of macros, async and higher-order programming. I spend a lot of time teaching low-level programming though, because I expect that most readers are least familiar with that.
Rust in Action is designed for people who like to learn with practical projects and who want to learn what “systems programming” is. I provide a fuller introduction in this Reddit thread. I recommend searching on Twitter for “rust in action” to see readers’ comments.
I think the database-from-scratch example was the most difficult. But only because I re-wrote the chapter multiple times. I originally wanted to provide a much richer database with a full query language, but ultimately pulled back because there was not enough space in the book. One of my drafts for the chapter was 90 pages long,.
From a different perspective, it was somewhat difficult to go back to my earlier examples. I became a much better Rust programmer as I wrote the book. And I kept fighting the urge to re-write what I had already written.