Boa: an experimental Javascript lexer, parser and compiler written in Rust

I understand that it's important to eat your own dog food, in order to experience the pain points yourself. But sometimes people think of self hosting as a symbol of something (pride maybe), and that's the wrong way to approach a programming problem in my opinion.

But if you want to keep the code simpler, a higher-level language could potentially give better performance, simply because it's easier to share data structures, avoid copying, etc. Additionally, things like immutable persistent maps are a great fit for environments in a compiler, and they are much easier to implement in a language with garbage collection.

That said, obviously some high-level languages are still going to be too slow without also putting in a lot of work. I think there's a sweet spot with languages that compile to reasonably fast machine code but are also garbage collected. Languages like OCaml, Go, Haskell. Though I personally wouldn't use Go, but that's for reasons other than performance.

2. The way I see it, re-implementing JS from scratch in a language that is designed to help avoid very common, often compromising programming mistakes around concurrency and memory management makes perfect sense. Eventually this might make it into browsers and web servers; environments that are executing untrusted code in the former case and are publicly exposed in the latter case. Having them be fast-yet-secure is important, isn't it?

Of course, it's early days, but you gotta start somewhere after all...