state-machine-example.txt

goblins/0@(guile-user) [1]> (define state-machine (spawn ^state-machine))
goblins/0@(guile-user) [1]> ($ state-machine 'hello)
$5 = "Hello world!"
goblins/0@(guile-user) [1]> ($ state-machine 'switch)
goblins/0@(guile-user) [1]> ($ state-machine 'hello)
$6 = "I'm the second state!"
goblins/0@(guile-user) [1]> 

state-machine.scm

(use-modules (goblins)
             (goblins actor-lib methods))

(define (^state-machine bcom)
  (define state-1
    (methods
     [(hello)
      "Hello world!"]
     [(switch)
      (bcom state-2)]))
  (define state-2
    (methods
     [(hello)
      "I'm the second state!"]
     [(switch)
      (bcom state-1)]))
  state-1)