[trivial automata
clinton@unknownlamer.org**20091028174621
 Ignore-this: 193622b3db42a3424035581ceba2a0e3
] addfile ./automata.scm
hunk ./automata.scm 1
+(use-modules (srfi srfi-9)
+	     (srfi srfi-1))
+
+(define (next-token stream)
+  (if (pair? stream)
+      (car stream)))
+
+(define (transition machine state)
+  ((cdr (assoc state (cdr machine)))
+   (cons (if (pair? (car machine)) (cdr (car machine)))
+	 (cdr machine))
+   (next-token (car machine))))
+
+(define (run-machine machine initial-state stream)
+  (transition (cons stream machine) initial-state))
+
+(define cadr-machine
+  `((init . ,(lambda (m v) (case v
+		       ((#\c) (transition m 'more))
+		       (else #f))))
+    (more . ,(lambda (m v) (case v
+		       ((#\a #\d) (transition m 'more))
+		       ((#\r) (transition m 'end))
+		       (else #f))))
+    (end . ,(lambda (m v) #t))))
+
+