Swift.rs is a Swift lexer (and future parser), and it is meant to be blazingly fast. Also, it's written in Rust, as every fast thing has to be written in Rust nowadays.
For my own educational purposes, and to prove that compliation speed can be improved by leveraging better lexing and parsing strategies.
We use Oxc (By Boshen) lexer and parsing strategies to build the best possible lexer and parser for Swift.
Very bare bones. Lexer can barely parse a few keywords and identifiers. But it's a start. Parser is also a long time away.
Don't.