wasmer-assemblyscript-example

An example of using Wasmer to run Assemblyscript generated Webassembly inside a Rust program.

How to Run

You'll need Rust and Node installed on your machine.

Build the WASM

To build the WASM, which we'll run inside the host program:

cd wasm

npm run asbuild:optimized

This will compile the Assemblyscript module down to WASM, resulting in a build/optimized.wasm file.

Build the Host

Now we've built the WASM, we need to build our Rust host. In the repo root run:

cargo build

This will install the Wasmer library (WASM runtime) and build our WASM executor.

Run it

./target/debug/wasmer-assemblyscript-example

🚀 You should see our WASM code logging 'Hello, World!' then exiting happily.

Extending it

This is a blueprint for embedding a WASM interpreter in your program. It doesn't do anything interesting yet, but it's an easy starting point for your WASM based projects.

• Replace Rust: Wasmer supports a whole heap of host languages, so you can run WASM with whatever program/language you want
• Replace Assemblyscript: As we compile our module down to WASM to run it, you can write your module in any language with a WASM backend (which is most of them by now ...)
• Extend imports: Right now our host exposes just a couple of functions to the loaded WASM, so we can't do much very interesting work. Add extra functions to the import_object variable to let your WASM do something more interesting.

For brevity & simplicity, the generated WASM is currently statically linked to the host at build time (using include_bytes!). So every time you change your WASM you'll need to re-build it and re-build the host. Which isn't ideal. You'll likely want to replace that with a file loader before you get too far.