That's a good point - I could map to an exception like that. I assume you mean the algebra of the reply message from the look up actor:
trait UserInfo case class AvailableUserInfo(firstName:String, lastName:String) case object MissingUserInfo That's an interesting idea too. Thanks. On Sun, Jun 29, 2014 at 6:55 AM, √iktor Ҡlang <viktor.kl...@gmail.com> wrote: > Hi Richard, > > since you are using Futures you'll have to deal with the case where the > Future fails anyway, so why not represent the failed lookup as a > NoSuchElementException? It's either that or expose the absence of value in > the algebra (which I'd prefer). > > > On Sun, Jun 29, 2014 at 3:40 PM, Richard Rodseth <rrods...@gmail.com> > wrote: > >> Hi Viktor >> >> The use case is an actor that processes "commands", creating "jobs". But >> first it has to look up something in the database to send to the job along >> with the other job parameters. The Option comes from the fact that the >> thing being looked up may not exist. >> >> As I mentioned, I first mapped the Future[Option[T]} to something like >> Future[JobMessage]. It worked out quite well in this case, I thought, and I >> have all the context I need in the Jobmessage I create. As an aside, I'm >> tempted to say one should almost always pipe to self, so that the actor >> doing the piping can handle the akka.actor.Status.Failure >> >> That said, if there are other suggestions for ways to unwind >> Future[Option], I'm all ears. >> >> >> On Sun, Jun 29, 2014 at 6:26 AM, √iktor Ҡlang <viktor.kl...@gmail.com> >> wrote: >> >>> `Future[Option[T]] pipeTo self` sounds like a bad idea because there is >>> no context to the message for the actor (it just gets a None, it doesn't >>> even know what Option[T] it was since the T is erased.) >>> >>> What's the use-case? >>> >>> >>> On Sun, Jun 29, 2014 at 3:34 AM, Richard Rodseth <rrods...@gmail.com> >>> wrote: >>> >>>> So I've run into the "Monads don't compose" problem and am a bit >>>> reluctant to tackle monad transformers and Scalaz at this point. >>>> >>>> I'm wondering what you all think about mapping the Future[Option[T]} to >>>> something like Future[MyMessageType] , piping to self, and then pattern >>>> matching on MyMessageType in the receive handler, forwarding to the >>>> ultimate destination or handling the error case as needed. >>>> >>>> -- >>>> >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>> >>>>>>>>>> Check the FAQ: >>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>> >>>>>>>>>> Search the archives: >>>> https://groups.google.com/group/akka-user >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "Akka User List" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to akka-user+unsubscr...@googlegroups.com. >>>> To post to this group, send email to akka-user@googlegroups.com. >>>> Visit this group at http://groups.google.com/group/akka-user. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> >>> >>> -- >>> Cheers, >>> √ >>> >>> -- >>> >>>>>>>>>> Read the docs: http://akka.io/docs/ >>> >>>>>>>>>> Check the FAQ: >>> http://doc.akka.io/docs/akka/current/additional/faq.html >>> >>>>>>>>>> Search the archives: >>> https://groups.google.com/group/akka-user >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "Akka User List" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to akka-user+unsubscr...@googlegroups.com. >>> To post to this group, send email to akka-user@googlegroups.com. >>> Visit this group at http://groups.google.com/group/akka-user. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- >> >>>>>>>>>> Read the docs: http://akka.io/docs/ >> >>>>>>>>>> Check the FAQ: >> http://doc.akka.io/docs/akka/current/additional/faq.html >> >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user >> --- >> You received this message because you are subscribed to the Google Groups >> "Akka User List" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to akka-user+unsubscr...@googlegroups.com. >> To post to this group, send email to akka-user@googlegroups.com. >> Visit this group at http://groups.google.com/group/akka-user. >> For more options, visit https://groups.google.com/d/optout. >> > > > > -- > Cheers, > √ > > -- > >>>>>>>>>> Read the docs: http://akka.io/docs/ > >>>>>>>>>> Check the FAQ: > http://doc.akka.io/docs/akka/current/additional/faq.html > >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user > --- > You received this message because you are subscribed to the Google Groups > "Akka User List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to akka-user+unsubscr...@googlegroups.com. > To post to this group, send email to akka-user@googlegroups.com. > Visit this group at http://groups.google.com/group/akka-user. > For more options, visit https://groups.google.com/d/optout. > -- >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>>>>>> Check the FAQ: >>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups "Akka User List" group. 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