Thank you. I suppose on a Source[T, Unit] the only option for an initial
materialized value is something provided externally or accessible through
the shape. I don't see any way to access attributes after supplying them,
for example. I don't actually have a use case for this now - just curious.
def makeSource(name:String): Source[Int, String] = {
val source: Source[Int, Unit] = Source(List(1,2,3)).named(name)
val mapped = source.mapMaterializedValue { x => name }
mapped
}
On Thu, Jan 28, 2016 at 12:03 AM, Viktor Klang <[email protected]>
wrote:
> mapMaterializedValue
>
> --
> Cheers,
> √
> On Jan 28, 2016 5:04 AM, "Richard Rodseth" <[email protected]> wrote:
>
>> I've since become aware that for something like counting a parent stream
>> for monitoring purposes I could use alsoTo to a counting sink.
>> But I'm still curious how a Source[T, Unit] becomes a Source[T, Mat], if
>> such a thing makes sense.
>>
>> On Wed, Jan 27, 2016 at 2:36 PM, Richard Rodseth <[email protected]>
>> wrote:
>>
>>> How does a Source[T, Unit] become a Source[T, M] ?
>>>
>>> I see that methods like via have a corresponding viaMat which let you
>>> provide a combiner to combine the materialized value of the previous stage
>>> and the next stage (I think)
>>>
>>> But how do you get the ball rolling with a Source?
>>>
>>> Say for example I have a stage that does a flatMapConcat and I want the
>>> final materialized value to contain a tuple of the count of the parent
>>> stream and a count of the final derived stream. I've done such counting
>>> using folds but only at the Sink level
>>>
>>> I believe I have read the relevant sections of the docs, so apologies if
>>> I am being slow on the uptake.
>>>
>>>
>>>
>> --
>> >>>>>>>>>> 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
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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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