just VS hermes

just

https://github.com/just-js/just Is another for a V8 runtime, it really shows how well optimized it is. https://www.techempower.com/benchmarks/#section=data-r21

i just tried recompiling v0.0.2 (https://github.com/just-js/just/releases/tag/0.0.2) of just-js and comparing it to current. for the completely static build on ubuntu 22.04 i see following:

0.0.2 (v8 v8.4.371.18) - file size: 15.2 MB, startup RSS: 8.4 MB

Not at all. Javascript, as well as java compiled into the bytecode, but just incrementally and at the runtime. You cannot compile typescript into bytecode directly (at least it intend to be like that). You can even compile js to executable (https://github.com/just-js/just). So no, typescript transpiles to javascript, whereas scala compiles to bytecode, it's different things

Trust me, these guys are insane and go to really extreme levels and use optimization techniques which are not generally prevalent among the general programming fraternity. for eg, look at pico.v it is awesome and just-js is truly unbelievable, then there is faf, most of them combine low level programming trickery to reach those insane numbers. Also some of the code may not be useful in a production app but they actually extract the juice out of the metal at every instance. Memory optimizations, compiler optimizations, postgresql wire implmentations, rust black magic, these guys are really crazy and passionate.

Hermes is a big one as well: low startup latency, low memory

https://hermesengine.dev/

Hermes

InstagramBundle.js.hbc.spk.xz is likely a compressed version of Hermes bytecode (js.hbc)"

In React Native's case, it uses an engine called Hermes:

📜 I made JSON.parse() 2x faster: Radek proposes to improve the performance of Hermes by using very fast C++ libs based on SIMD instructions. Interesting to read even if you don't use React-Native. Ongoing discussions on the Hermes PR.

Thanks! There's a preliminary PR with a discussion here: https://github.com/facebook/hermes/pull/933 (and broader context here: https://github.com/facebook/hermes/issues/811 ). But we'll see if there's any interest on Hermes' side to merging it. They definitely want to improve the parser, but it's unclear to me if they want to take on the simdjson/simdutf dependencies.

For me it’s a JS engine for React Natve - https://hermesengine.dev/

💉 Building and injecting a JS bundle a basic concept: If the native code wasn’t changed, simply create JS bundle and inject it into the precompiled application. (You must take an extra step to convert a js file to bytecode if you use the Hermes js engine.)