rusty-js

a JIT Javascript Engine written in rust. It is an experiental enigine inspired by golang's insterface type.

Overview

This Javascript Engine is an embeddable written in pure rust. It supports the ES2022 Syntax including modules, asynchronous functions, generators and more. Unlike traditionsl engines that uses nan-boxing, Rusty uses dynamic dispatch to run operations on value, determination(branching) of types during runtime is no longer necessary, the jitted code size is therefore reduced.

value representation

#[cfg(target_pointer_size = "64")]
struct JSValue{
   value:u64,
   vtable:*const Vtable
}

Jitted add operation

let a:JSValue = 0.into();
let b:JSValue = 1.into();

let result = a.vtable.add(a.value, b); // returns 1

JIT stages

	Progress	Backend	Missing features
interpreter	70%	Bytecode	Speculation
baseline jit	50%	Cranelift	fallback to interpreter
optimise jit	0%	?

Missing Features

Regex
Class optimisation
TypeScript

Async and generator support

	ELF (Linux, BSD, bare metal, etc)	Darwin (macOS, iOS, etc)	Windows
x86_64	✅	✅	✅
x86	✅	❌	✅
AArch64	✅	✅	❌
ARM	✅	❌	❌
RISC-V	✅	❌	❌

Ecma Roadmap

for more information, see here.

YC-Lammy/rusty-js