module DFA

open System

type State = { name: String }

type DFA = {
    sigma: Char list
    states: State list
    delta: State -> Char -> State
    beginState: State
    acceptingStates: State list
}

let processChar (dfa: DFA) (state: State) (char: Char) =
    dfa.delta state char

let rec processCharArray (dfa: DFA) (state: State) (charArr: Char list) =
    match charArr with
    | [] -> state
    | _ -> processCharArray dfa (processChar dfa state charArr.Head) charArr.Tail

let acceptsWord (dfa: DFA) (word: String) =
    dfa.acceptingStates
    |> List.contains (processCharArray dfa dfa.beginState (Seq.toList word))