import time
from circuits import BaseComponent, Worker, Debugger, task, handler

class App(BaseComponent):
    def factorial(self, n):
        time.sleep(.2)
        if n > 1:
            nn = yield from self.call(task(self.factorial, n-1))
            return n * nn.value
        else:
            return 1

    @handler("started")
    def started(self, *args):
        Worker().register(self)
        rv = yield self.call(task(self.factorial, 5))
        print(rv.value)
        self.stop()

(App() + Debugger()).run()