Regex Chess: A 2-ply minimax chess engine in 84,688 regular expressions
(nicholas.carlini.com)
This is amazing. I'm at loss for words.
replyDuring my CS years I remember being fascinated by NFA's, as opposed to boring single universe DFA's.
For some reason I internalized that I would never see something like an NFA implemented beyond text books.
Then came Carlini.
But... they are equivalent?
replyUpon reading the title, this is one of those "I know that's possible, but I'd never bother to implement it" things, although this particular implementation isn't exactly what I had in mind.
replyI get "illegal move, game over" like 50% of the time, chrome on android.
replyThe technical write up is worth perusing but I played a game before reading and accidentally found a winning strategy immediately. I'm not sure if this is a result of the 2-ply nature of the engine or if the mentioned deficiencies account for this but the computer did not act to prevent checkmate in 1 (without any intervening check); the game I played was (in algebraic notation):
1. e4 e5
2. kf3 kf6
3. kxe5 kxe4
4. d4 kxf2
5. Kxf2 a5
6. Qf3 b5??
7. Qxf7
1-0
replyThis is absurd. I did not realize you could do nearly this much computation in regex.
replyIt’s turing complete so you could compile almost any language to regex. You might have to build a vm for some languages, also in regex. The point is, it’s regex all the way down.
reply2025
replyThis is like a fever dream.
reply