Adding lookbehinds to rust-lang/regex
An annotated guide to adding captureless lookbehinds to the Rust linear-time regex engine.
In a previous blogpost, Erik wrote about how he implemented the linear time matching algorithm from [RegElk+PLDI24] in the popular regex engine RE2. In this one, we're looking at how to do the same thing for the official regex engine from the Rust language. Namely, we add support for unbounded captureless lookbehinds.