Just to clarify, when you say "not for beginners" do you mean beginners to Rust or programming in general?
edit: Based on your "It was my first introduction to rust" comment I think maybe you meant programming beginners?
edit: Based on your "It was my first introduction to rust" comment I think maybe you meant programming beginners?
The book basically uses the crate clap to create all the CLTs, along with specific crates for regex and creating ascii tables for the cal clone.