oxc_parser uses bumpalo (IIRC) to compile an AST into arena from a string. I think the String is outside the arena though, but their lifetimes are "mixed together" into a single 'a, so lifetime-wise it's the same horror to manage. But manage they did.
If you can get a full JSON parser working then maybe I’m just wrong. Arrays, objects with keys/values, etc.
I’d like to think I’m a decent Rust programmer. Maybe I just need to give it another crack and if I fail again turn it into a blog post…