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Getting ready
This time, we are going to create two projects: one that offers some type of function and another one to use it. Therefore, use cargo to create both projects: cargo new rust-pilib --lib and cargo new pi-estimator. The second command creates a binary executable so we can run the compilation result, while the former is a library (crate).
This recipe is going to create a small program that prints out estimations of pi (
) and rounds them to two decimal places. It's nothing fancy and easy for anyone to understand.
Naming crates is hard. The main repository ( https://crates.io/) is very permissive and has already seen name squatting (where people reserve names with the intent to sell them—think of names such as YouTube or Facebook, which would make nice API client names for these companies), and many crates are re-implementations of C libraries or wrap them. A good practice is to call the repository or directory rust-mycoolCwrapper and use mycoolCwrapper to name the crate itself. This way, only issues specific to your crate come in while the name is easy to guess in people's dependencies!