Got it. Thanks!
On Mon, Sep 22, 2014 at 11:32 PM, Björn Antonsson <
bjorn.antons...@typesafe.com> wrote:
> Hi Richard,
>
> Your foreach will run through the list of Future[String] and on every
> single Future it will attach an onComplete block (this is what pipeTo
> does). The reason that this is ok is that you read the value of sender when
> you call the method pipeTo. If you on the other hand had written the
> onComplete code block yourself inside the foreach, the code would have been
> broken. That was the not so obvious thing I was referring to.
>
> B/
>
> On 22 September 2014 at 19:07:51, Richard Rodseth (rrods...@gmail.com)
> wrote:
>
> I'm aware of the caveats about sender and closing over mutable state, but
> in this case the list was a plain list, not a Future. But thanks for
> showing an alternative.
>
> On Mon, Sep 22, 2014 at 7:30 AM, Björn Antonsson <
> bjorn.antons...@typesafe.com> wrote:
>
>> Hi Richard,
>>
>> When dealing with futures, inside actors you should generally be careful
>> with using sender, since the code that is executed when the future is
>> completed isn't run inside the actor and the meaning of sender might have
>> changed. In this case, the pipeTo pattern will keep you safe, but it's easy
>> to mess up.
>>
>>
>> If you don't plan to use the intermediate I would collapse the map and
>> foreach into a single foreach.
>>
>>
>> val recipient = sender
>> requests.foreach { responseFuture => {
>> responseFuture.map(response => s"success $response").recover({ case _
>> => "failed"}) pipeTo recipient
>> }}
>>
>> B/
>>
>> On 19 September 2014 at 20:46:50, Richard Rodseth (rrods...@gmail.com)
>> wrote:
>>
>> I'm still getting used to all the flavours of future composition. Fun
>> stuff. Is there a better way than the following to pipe a list of futures
>> to the sender (one message per future) ?
>>
>> val requests:List[Future[SomeResponse]] = ...
>>
>> val messages:List[Future[String]] = requests.map { responseFuture => {
>>
>> val msgFuture:Future[String] = responseFuture.map(response =>
>> s"success $response").recover { case _ => "failed"}
>>
>> msgFuture
>>
>> }}
>>
>> messages.foreach { msg =>
>>
>> msg pipeTo sender
>>
>> }
>> --
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>> --
>> Björn Antonsson
>> Typesafe <http://typesafe.com/> – Reactive Apps on the JVM
>> twitter: @bantonsson <http://twitter.com/#!/bantonsson>
>>
>> --
>> >>>>>>>>>> Read the docs: http://akka.io/docs/
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>
> --
> >>>>>>>>>> Read the docs: http://akka.io/docs/
> >>>>>>>>>> Check the FAQ:
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>
> --
> Björn Antonsson
> Typesafe <http://typesafe.com/> – Reactive Apps on the JVM
> twitter: @bantonsson <http://twitter.com/#!/bantonsson>
>
> --
> >>>>>>>>>> Read the docs: http://akka.io/docs/
> >>>>>>>>>> Check the FAQ:
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--
>>>>>>>>>> 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
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