mjs VS just

mjs

I hear you loud and clear.

This implementation is nuts. A decent chunk (but still very small subset) of ES5 in under 1400 lines of very readable C code. It includes a mark-and-sweep GC and an FFI.

It doesn't have an AST or a bytecode VM. It just interprets directly off of source code.

Take a look: https://github.com/cesanta/elk/blob/master/elk.c.

This implementation really sets a new bar for me in terms of compact-but-readable language implementations.

Separately, this isn't even Cesanta's only embedded JavaScript implementation. They also have: https://github.com/cesanta/mjs. This implementation is a bit more complete and is much bigger.

In the past I've programmed with ESP8266 with Mongoose OS using mJS - https://github.com/cesanta/mjs but it has on 1.5K GitHub stars and I assume there are other alternative as well for Python language

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.