Sample StateMachine usage for Reactor

StateMachineSample.groovy

// reactor-fsm: github.com/jbrisbin/reactor-fsm
// reactor: github.com/reactor/reactor

StateMachine ioMachine = new StateMachine.Spec().
  sync().
  using('idle', 'wait', 'send-request', 'response-ready').
  when('send-request') { prev ->
    def msg = requests.peek()
    send(msg)
    'wait'
  }.
  when('response-ready') { prev ->
    Promise p = requests.pop().promise
    def msg = responses.pop()
    p.set msg
      
    requests.empty ? 'idle' : 'send-request'
  }.
  get()


// when sending
requests << new Message(req)

if(ioMachine.current() == 'idle') {
  // currently waiting to send since nothing is inflight
  ioMachine.state('send-request')
}