Luna is a reeeaaally tiny, yet expanding, compiler for WebAssembly Text Format, written in Go and built as one of my quest to conquer the WebAssembly dungeon.
(I just wanted to build something like wat2wasm)
It is so tiny that can only make the four operations (addition, subtraction, multiplication and division) with
i32 type numbers.
I've built Luna because I wanted to learn how to build a compiler while learning WebAssembly. So Luna was built for DEMONSTRATION and EDUCATIONAL purposes first.
The goal of Luna is not to do fancy stuff to replace (in a long distant future) solid tools like wat2wasm, wasmer or others...
The goal of this project is to become a
useful landmark for anyone approaching WebAssembly and/or for anyone that wants to develop a compiled-to-wasm programming language.
I tried to document each section of the code as much as I could (I'm still doing it) with link to resources I've studied while building this, but if you want to improve it, feel free to open issues and pull requests.
How it works
Followed the amazing articles about the Chasm compiler (a WAT compiler written in Typescript for the Chasm language) and a guide to write a WAT compiler in Rust
- Luna takes a
.watfile (or string if used in the browser)
- Splits it into tokens
- Creates a very simple AST of the tokens
Use it in the browser
Luna can also be used in the browsers
command will build (or update) with TinyGo the
./example/main.wasm file to be imported in the browser In the
./example directory there's a working example of how to do that.
make updatewill simply update/replace the existing main.wasm
💡- Check the console to see the tokenizer and the parser outputs
Luna also implements a really tiny runtime that can run the exported functions. Read more about it in
- syscall/js set up (or simply comment out the startLuna function and the syscall/js import)
Currently Luna supports only the renaming of the exported function and some order scrumbling More interactivity
Currently Luna supports only addition More arithmetics
Expansion of Wat syntax
To contribute simply
- create a branch with the feature or the bug fix
- open pull requests
Luna is by no means finished there are a lot of things that can be implemented and A LOT of things that can be improved. Any suggestions, pull requests, issues or feedback is greatly welcomed!!!
Per aspera ad astra!
Made it so that the runtime doesn't need to parse the AST each time a function is invoked.
Front end refactor
I have in mind a huge front end refactor for Luna. Basically it will be toward an interactive
guide: teaching WebAssembly with Luna (which is the main scope of this)
I'm currently deciding which framework or libraries to utilize (leaning toward Docusaurus or Gitbook), but if you have any suggestions and want to drop something feel free to comment 💯
Add multi value
Now that Luna supports subtractions and addition, should be able to call different functions like this