This is an excellent read. I would suggest reading this also (maybe even before), as it provides one of the simplest (incomplete, but still useful) regex imple

This is an excellent read. I would suggest reading this also (maybe even before), as it provides one of the simplest (incomplete, but still useful) regex implementations you'll ever see: https://www.cs.princeton.edu/courses/archive/spr09/cos333/beautiful.html https://www.cs.princeton.edu/courses/archive/spr09/cos333/be... It suffers from the problems remedied by the original submission (backtracking instead of DFA), but the code is shorter and simpler. They're great to compare.