I also don't know all the details, but the Rust parser tokens contain horrible crimes, primarily because of macros. All I wanted to say was that applying DoD to the parser in Rust would (IMO) be much more difficult than in Zig, because language differences and different approaches to error reporting. Not saying it's impossible ofc. That being said, I don't really think so much effort would be worth here, the gain would be minimal in the grand scheme of things; we have bigger perf. problems than parsing.