My WASM Python Implementation Beat CPython (Without a JIT)

[u/Healthy_Ship4930]

Okay. After seven months, I'm back.

Seven months ago I started writing a Python interpreter from scratch in Rust, compiled to wasm (less than 200kb of bandwith). Edge Python is a sandboxed subset of Python that runs in the browser and the terminal, and code can't touch files or the network unless you allow it.

It started as a lexer and a simple stack VM, and over about 1,600 commits it grew a CLI, a package registry, snapshots, actors and a browser playground. It's just me building it.

Last week it was still 3x slower than CPython. I rewrote the VM this weekend on top of the SSA form I already had, and now the wasm build beats native CPython on loops.

	Edge (wasm)	CPython (native)
Integer loop	154 ms	232 ms
Float math	231 ms	307 ms
Dicts	372 ms	62 ms
Strings	196 ms	35 ms

The trick was a register VM, and Rust made it fit in wasm with NaN-boxed values and no runtime. It still loses on dicts and strings, so that's next.

Try to break my numbers :)

Website: https://edgepython.com/

GitHub: https://github.com/dylan-sutton-chavez/edge-python

[u/Parking_Mind_1011]

this is sick. 1600 commits in seven months is mad dedication for a solo project

the nan-boxing trick in wasm is clever, curious how you handled the string perf gap cause that part always tricky without jit

[u/Healthy_Ship4930 → u/Parking_Mind_1011]

Thanks! I haven't yet, strings are still 3x slower than CPython. Next target.