RDL: Rust data language

A hobby implementation of Clojure like Data language with a runtime written in Rust and running both natively and on the web with Wasm.
Try it out online [Wasm REPL] »

Explore how it was made

Table of Contents

• About the Project
  • Motivation
  • Crates Used
• How it was made
• What is next
• License
• Contact
• Acknowledgments

About The Project

This project initially came from the idea of writing a clojure runtime in a language other than Java. When I first started writing anything it was call CDL: C++ Data Language and I wrote it in C++. Because the language ecosystem does not have something as wonderful as Cargo and Crate.io I started out writing everything from scratch. I also took this as an opportunity to use all the new not yet released tools of C++. And eventually things broke. So that became an opportunity to finally learn Rust, after just studying it at an academic level.

Motivation

The idea of having a Data language for rust is not to far fetched. A direct translation of a language like Clojure, which is the status of this project right now, is not the best fit for a such strongly typed language as Rust. However the use of persistent data structures with structural sharing plays very well with the rust type and lifetime systems. A data language which is focused on abstracting away the data access and creating a data oriented way of creating and generating generic rust trait functionality could be a great application for just this.

The of the great benefits with a Data language that can be compiled but also be run interactively in a runtime is that it enables REPL driven development. REPL driven development is great tool for getting fast feedback when iterating on design and business logic.

Crates Used

• im

  • Blazing fast immutable collection datatypes for Rust.

  • Definitely a well designed library, pretty much the reason I restarted this project in Rust.

    Docs »

• peg

  • rust-peg is a simple yet flexible parser generator that makes it easy to write robust parsers

  • After failing to write a compile time generated PEG parser in C++, I can only exclaim how much nicer it is in Rust with macros.

    Docs »

• mogwai

  • minimalist, obvious, graphical web application interface

  • Definitely the most interesting of all the Rust Wasm frontends. Not using a shadow-dom and instead just sending messages was a nice change of pace.

    Docs »

• wasm-bindgen

  • Facilitating high-level interactions between Wasm modules and JavaScript

  • I don't think I've ever had a more seamless experience with just getting something that if of this scope to just work out of the box. I truly hope Wasm is the future of the internet.

How it was made

TODO Might add some more information on how this project was made.

However if anyone want so build it should be as easy as just cloning the repo and running cargo build. Run cargo run -p rdl to run the test REPL. It does however require nightly as I ended using some unstable features. Some just because they were nice and some that I wasn't sure how to without (arc_new_cyclic), at least without some unsafe code.

If you want to compile the Wasm SPA just follow the commands in the rdl-web-demo README. Also you can try it out online this projects github pages. [Wasm REPL] »

What is next

There are many things that can be done but I am not sure I will continue iteration on this Clojure like clone.

I already have another branch rework-enum where I unified the number runtime types into an auto promoting type. However I feel like that is the wrong way forward. It is to rigid. If I were to take another stab at this Rust data language idea it would this:

• Design a trait oriented syntax with focus on transpiling into Rust trait generics.

• Build a dynamic type runtime based on this which can be evaluated in a REPL

  • With the caveat that it might need some recompilation and glue / tooling to enable interoperability with current projects.

• Create dual compilation modes one with REPL and marshaling and one without

  • Can definitely see the benefit in this if it could be used for Wasm web applications while they are running.

License

Distributed under the MIT License. See LICENSE for more information.

Contact

Axel Boldt-Christmas - xmas1915@gmail.com

Project Link: https://github.com/xmas92/rdl

Acknowledgments

• The great resource that Crates.io and Docs.rs are. Standardizing and centralizing both build tools and documentation makes things so much easier.