[Python-Dev] Active Objects in Python

[Bruce Eckel]

Oops. I forgot to add that to the list. Yes, in the working example
of Active Objects that I've written in Java J2SE5, when you send a
message to an active object, you get back a Future<ReturnType>, which
I suspect would be the same as your Deferred.

Tuesday, September 27, 2005, 7:41:27 PM, Christopher Armstrong wrote:

> On 9/28/05, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
>> Nick Coghlan wrote:
>>
>> > PEP 342's yield expressions can probably be used to help address that problem,
>> > though:
>> >
>> >    class SomeAO(ActiveObject):
>> >      def processSomeMessage(self):
>> >        msg = yield
>> >        # Do something with the message
>> >        next_msg = yield makeSomeBlockingCall(self)
>> >        # Do something with the next message
>>
>> I don't see how that helps, since makeSomeBlockingCall()
>> is evaluated (and therefore blocks) *before* the yield
>> happens.

> Sounds like makeSomeBlockingCall is just misnamed (probably depending
> who you ask).

> I wrote a small library recently that wraps Twisted's Deferreds and
> asynchronous Failure objects such that you can do stuff like

> try:
>  x = yield remoteObject.getSomething()
> except Foo:
>  print "Oh no!"

> This is just a 2.5-ification of defgen, which is at
> twisted.internet.defer.{deferredGenerator,waitForDeferred}. So anyway,
> if your actor messages always return Deferreds, then this works quite
> nicely.


> --
>   Twisted   |  Christopher Armstrong: International Man of Twistery
>    Radix    |    -- http://radix.twistedmatrix.com
>             |  Release Manager, Twisted Project
>   \\\V///   |    -- http://twistedmatrix.com
>    |o O|    |
> w----v----w-+
> _______________________________________________
> Python-Dev mailing list
> Python-Dev at python.org
> http://mail.python.org/mailman/listinfo/python-dev
> Unsubscribe:
> http://mail.python.org/mailman/options/python-dev/bruceeckel-python3234%40mailblocks.com


Bruce Eckel    http://www.BruceEckel.com   mailto:BruceEckel-Python3234 at mailblocks.com
Contains electronic books: "Thinking in Java 3e" & "Thinking in C++ 2e"
Web log: http://www.artima.com/weblogs/index.jsp?blogger=beckel
Subscribe to my newsletter:
http://www.mindview.net/Newsletter
My schedule can be found at:
http://www.mindview.net/Calendar