RE#: how we built the world's fastest regex engine in F#
Summary
RE# is a new general-purpose regex engine for .NET/F#, introducing intersection and complement with linear-time guarantees. The post explains the derivative-based approach, minterm compression, and lazy DFA construction, emphasizing practical performance and context-aware matching. It also positions RE# against backtracking engines and NFAs and points to open-source code, a web app, and a POPL 2025 paper for deeper details.