Rats is an experimental, type-level functional programming library for Rust, based heavily on Scala's Cats (which itself is based heavily on Scalaz). There have been a few explorations in this space, but I believe Rats takes it much further than was previously possible.
Rats has a few goals:
- Implement functional abstractions as close to zero-cost as can be achieved, while still maintaining the usefulness of these abstractions. This is a delicate balance.
- Explore functional programming in the context of Rust.
- Learn more about FP, and get better at Rust.
At the moment, Rats relies on a non-zero cost embedding of higher-kinded types. For this reason, Rats is probably not
appropriate for performance critical programs. However, it does enable some powerful abstractions that might be useful
in less performance-critical applications. For more on the HKT embedding and how it works, see lifted.rs.
Due to the performance constraints, Rats will likely only be of interest to Rust programmers curious about functional programming, and to functional programmers who are curious about Rust. At the moment, it is a single person's labor of madness and unemployment, but there are lots of areas where Rats can be expanded, and I'd be very happy to accept contributions.
TODO
A huge thanks to the Cats project and contributors, who are responsible for everything I know about type-level functional programming.
Rats is dedicated to Ada, Beorn, Basil, Elsie, Gracie, Rosie, Sally, Two-of-Three and Yuri. Their lifetime's were much too short.