There was a back and forth on that subject a few years back: Mozilla rewrote the...

There was a back and forth on that subject a few years back: Mozilla rewrote their sourcemap parser from JS to naïve Rust (/WASM) for a 5.89x gain, mraleph objected to the need and went through an epic bout of algorithmic and micro-optimisations to get the pure JS to a similar level, then the algorithmic optimisations were reimported into the Rust version for 3x further gain (and much lower variance than the pure JS).