quickjs-wasm-sys: Wasm QuickJS bindings for Rust

FFI bindings for a Wasm build of the QuickJS Javascript engine.

Building this crate

• Install the wasi-sdk for your platform
• Set the QUICKJS_WASM_SYS_WASI_SDK_PATH environment variable to the absolute path where you installed the wasi-sdk

For example, if you install the wasi-sdk in /opt/wasi-sdk, you can run: bash export QUICKJS_WASM_SYS_WASI_SDK_PATH=/opt/wasi-sdk