bridge

Simple examples for Python-Rust interop via WebAssembly.

Commands

To run microbenchmarks:

python run.py

To install wasmtime with pip:

pip install wasmtime

To recompile microbenchmarks.wasm:

rustup target add wasm32-wasi
rustc lib.rs --codegen opt-level=3 --crate-type=cdylib --target=wasm32-wasi

Context

Foreign function interfaces (FFI) allow programs written in one programming language to call routines in another language. This can be done through dynamic libraries i.e. .dylib/.so/.dll files for Mac/Linux/Windows respectively, as discussed in the post here re: using Python to call Rust.

WebAssembly is a way of taking code written in programming languages other than JavaScript and running that code in the browser; this effectively means the compiled .wasm binary is agnostic to the choice of processor and OS. Lin Clark has an excellent intro series on WebAssembly here.

The WebAssembly project has expanded beyond the browser, with wasmtime as the independent runtime and WASI as the unified systems interface. This could potentially make the .wasm format the new standard in portable binaries for cross-language bridges.

The example in this repo calculates in pure Python and in Python with Rust via WebAssembly (1) the 10,000th prime number, (2) pi, and (3) the 25th Fibonacci number, with local microbenchmarks as follows:

Minimal examples to compile and run WebAssembly can be found here.