[truth_seeker]

I wonder how much optimization will it bring to compared to existing JS runtimes such as V8.

Thanks to competing world for web browsers, JS runtimes not only efficiently parse to optimized native code but also provide really good JIT compilation benefits.

Speculative optimization for V8 - https://ponyfoo.com/articles/an-introduction-to-speculative-...

Parallel and Concurrent GC - https://v8.dev/blog/trash-talk

Good summary on 10 years of V8 - https://v8.dev/blog/10-years

[ridiculous_fish]

v8-style engines do not parse to optimized native code.

As described in the links, v8 parses to an AST, which then is compiled to bytecode. A bytecode VM then executes the JS, collecting runtime type information, which is input (along with the bytecode itself) into the next compilation tier; only at that point is machine code generated.

The key idea is that v8 expects to execute the JS code before it can generate native code. It won't generate native code from parsing alone.