Pretty cool! I was having trouble understanding the relationship between monoids and deterministic finite automata, but once I worked out an example by hand I w

Pretty cool! I was having trouble understanding the relationship between monoids and deterministic finite automata, but once I worked out an example by hand I was able to implement that transformation in Haskell: data MonoidMachine monoid input = Monoid monoid => MonoidMachine (input -> monoid) (monoid -> Bool) -- From the proof of Theorem 1 in the paper. translate :: DFA state input -> MonoidMachine (Endo state) input translate (DFA _ _ delta initial accepting) = MonoidMachine f g where f a = Endo (\q -> delta q a) g (Endo h) = h initial `member` accepting runMonoidMachine :: MonoidMachine monoid input -> [input] -> Bool runMonoidMachine (MonoidMachine f g) = g . mconcat . map f The rest is here: https://gist.github.com/newjam/428613f083d289b83de0ddfeedf4e9a7 https://gist.github.com/newjam/428613f083d289b83de0ddfeedf4e...