As far as I know the « regex » crate is used in some places. But interpreting block rules has a lot to do with specific options and behaviors which are pretty t

As far as I know the « regex » crate is used in some places. But interpreting block rules has a lot to do with specific options and behaviors which are pretty tailored to the task and it would not be easy to use off the shelf regex implementations for this. Although I myself looked at Hyperscan in the past for the purpose of blocking ads (the performance looks amazing!).