Rust -> WASM -> Web Build
In order to understand what's going on under the hood of current Rust/WASM compilation toolchains (such as wasm-pack or even just cargo build with a WASM target), I wanted to create a project with the least amount of tooling possible in order to get compiled Rust code running in a browser.
In this example, I've created a Rust function that adds together two numbers. The function is compiled to WASM, and then used to interactively add together two numbers in the browser. Yay!
Note: I've only run this on MacOS. Linux will probably work, but Windows will probably not.
Prerequisites
- Install Rust: The
rustccompiler is necessary to compile- You may also need to add the nightly build and the
wasm32-unknown-unknowntarget to therustuptoolchain
- You may also need to add the nightly build and the
- Install Python 3: This'll allow running a simple HTTP server.
- Optional: Install the WABT toolkit
- This step is purely to be able to read the compiled WASM in a WAT format. If you omit, make sure to comment out line 8 in
run.sh.
- This step is purely to be able to read the compiled WASM in a WAT format. If you omit, make sure to comment out line 8 in
Running
$ chmod +x ./run.sh && ./run.sh
The chmod +x ./run.sh call is only necessary on the first run. Any subsequent runs can just use ./run.sh.
If successful, you should see the following output:
Serving HTTP on :: port 8000 (http://[::]:8000/) ...
You can then open http://localhost:8000 in a browser to see the code in action.