Porffor: A from-scratch experimental ahead-of-time JS engine

At windmill.dev, when users deploy their code, we use Bun build (which is similar to esbuild) to bundle their scripts and all their dependencies into a single js file to load which improve cold start and memory usage. We store the bundle on s3 because of the size of the bundles.

If we could bundle everything to native that would completely change the game since as good as bun's cold start is, you can't beat running straight native with a small binary.

I'd love to know if there's a way to compile NodeJS to native libraries with this! I have a process [0], but it's a bit hacky and error prone

[0] - https://github.com/ijustlovemath/jescx

I have thought about doing this and I just can't get around the fact that you can't get much better performance in JS. The best you could probably do is transpile the JS into V8 C++ calls.

The really cool optimizations come from compiling TypeScript, or something close to it. You could use types to get enormous gains. Anything without typing gets the default slow JS calls. Interfaces can get reduced to vtables or maybe even straight calls, possibly on structs instead of maps. You could have an Int and Float type that degrade into Number that just sit inside registers.

The main problem is that both TS and V8 are fast-moving, non-standard targets. You could only really do such a project with a big team. Maintaining compatibility would be a job by itself.

It's awesome to see how more JS runtimes try to approach Wasm. This project reminds me to Static Hermes (the JS engine from Facebook to improve the speed of React Native projects on iOS and Android).

I've spent a bit of time trying to review each, so hopefully this analysis will be useful for some readers. What are the main commonalities and differences between Static Hermes and Porffor?

  * They both aim for JS test262 conformance [1]
  * Porffor supports both Native and Wasm outputs while Static Hermes is mainly focused on Native outputs for now
  * Porffor is self-hosted (Porffor is written in pure JS and can compile itself), while Static Hermes relies on LLVM
  * Porffor currently doesn't support async/promise/await while Static Hermes does (with some limitations)
  * Static Hermes is written in C++ while Porffor is mainly JS
  * They both support TypeScript (although Static Hermes does it through transpiling the TS AST to Flow, while Porffor supports it natively)
  * Static Hermes has a fallback interpreter (to support `eval` and other hard-to-compile JS scenarios), while Porffor only supports AOT compiling (although, as I commented in other thread here, it maybe be possible to support `eval` in Porffor as well)

In general, I'm excited to see if this project can gain some traction so we can speed-up Javascript engines one the Edge! Context: I'm Syrus, from Wasmer [3]

[1] https://github.com/facebook/hermes/discussions/1137

[2] https://github.com/tc39/test262

[3] https://wasmer.io

Ecmascript 4 was an attempt to add better types to the language, which sadly failed a long time ago.

It'd be nice of TS at least allowed for specifying types like integer, allowing some of the newer TS aware runtimes could take advantage of the additional info, even if the main TS->JS compilation just treated `const val: int` the same as `const val: number`.

I wonder if a syntax like

    const counter: Number

would be acceptable.