nostr:npub1anuyv4p2tf59agnyryvm0th9vkcsgmnkcj9vda73n7ryv4jp4kgq07dxd2 (when I say "maintaining many parallel possibilites at a time", I'm thinking of this "Implementation: Simulating the NFA" section from https://swtch.com/~rsc/regexp/regexp1.html where he simulates an NFA using an array of states)