slime/bin/automata.slime

(import "sets.slime")


(define (make-dfa Q S delta q0 F)
  (let ((q q0))
    (lambda (s)
      (mutate q (delta q s))
      `(,(if (set-contains? F q) :accept :fail) ,q))))


(define (delta q s)
  (cond (s (case q
             (("q0") (case s (("M") "q1")))
             (("q1") (case s (("A") "q0")
                             (("G") "q2")))
             (("q2") (case s (("E") "q0")))))
        (else q)))


;; (make-delta
;;  ("q0" :: "M" -> "q1")
;;  ("q1" :: "A" -> "q0"
;;           "G" -> "q1")
;;  ("q2" :: "E" -> "q0"))

(define aut (make-dfa (make-set "q0" "q1" "q2")
                      (make-set "M" "A" "G" "E")
                      delta
                      "q0"
                      (make-set "q0")))

(printf (aut "M"))
(printf (aut "A"))
(printf (aut "M"))
(printf (aut "G"))
(printf (aut "E"))