alt Hacker NewsYou get stricter enforcement of public APIs and dependencies. You can't import anything you haven't declared as a dep, and cycles are impossible. Rustdoc by default shows only your intended public API.
OTOH if you have one crate with lots of modules, it's tempting to import anything anywhere and use pub(crate). Rustdoc needs to be configured to show private items if you want to see internal APIs.
Exactly. Being able to organize your code in a way that provides distinct responsibilities per crate is just good practice.
And then the ability to enforce a formalized layer between crates and the way that they assemble into your application (i.e. the public API) is powerful for comprehension and maintainability. I go as far as documenting each crate with its own README that presents it as a standalone component with usage instructions, much like an open source library, even if it's only ever used in a single system.