[PEAK] Re: peak.events.activity

[P.J. Eby]

At 09:41 PM 3/4/2009 -0500, Andrew Svetlov wrote:
>It will be great if you add to Activity.txt example of receiving
>values from subtasks in more clean way.
>
>Something very simple, like
>
>from peak.events import trellis, activity
>
>
>class TaskExample(trellis.Component):
>     trellis.attrs(
>         start = False,
>         stop = False
>     )
>
>     def wait_for_start(self):
>         i = 0
>         while not self.start:
>             yield "waiting to start %i"%i
>             yield activity.Pause
>             i += 1
>
>     def wait_for_stop(self):
>         i = 0
>         while not self.stop:
>             yield "waiting to stop %i"%i
>             yield activity.Pause
>
>
>     @activity.task
>     def demo(self):
>         for i in self.wait_for_start():
>             print i
>             yield i
>         print "starting"
>         for i in self.wait_for_stop():
>             print i
>             yield i
>         print "stopped"

The above should read:

    yield self.wait_for_start()
    yield self.wait_for_stop()

There is no need to loop over the results.


>It's obvious for me now: when I want to get result from subtask I need
>to iterate over and pass all unexpected results to upcoming stream.
>But it was not obvious after documentation reading.
>
>I'm wrong?

Yes.  ;-)  It's even easier than that, you just yield the invocation; 
you don't loop over it.

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