The Dyon[1] language would probably make a good basis for a repl for Rust. It shares many concepts with Rust including a version of ownership. [1] https://gith

The Dyon[1] language would probably make a good basis for a repl for Rust. It shares many concepts with Rust including a version of ownership. [1] https://github.com/PistonDevelopers/dyon https://github.com/PistonDevelopers/dyon You might also be able to link the repl with Rust Language Server which could be linked with incremental compilation, letting you define modules or pub fn's dynamically.