Hi there Victor, That’s the “materialized value” type parameter: read the docs to learn more about it: - http://doc.akka.io/docs/akka/current/scala/stream/stream-flows-and-basics.html#defining-and-running-streams - http://doc.akka.io/docs/akka/current/scala/stream/stream-composition.html#materialized-values
Basically it’s a well-typed mechanism for stream elements to expose control or information mechanisms. Read also the scaladoc of the operation you just posted, it explains what the value is in this case. Happy hakking — Konrad `kto.so` Malawski Akka <http://akka.io> @ Lightbend <http://lightbend.com> On 11 September 2017 at 18:33:01, Victor Caballero ([email protected]) wrote: Hello, I am intrigued by the mechanisms in which errors/exceptions in the Future wrapped by Source.fromFutureSource are handled or if they can even be handled. Also, the type signature of the method is: def fromFutureSource[T, M](future: Future[Graph[SourceShape[T], M]]): Source[T, Future[M]] I don't understand the return type: Source[T, Future[M]]. Can anyone explain why is the Future here? What is the use of the second type parameter of Source[T, M]? Which is usually NotUsed? Thank you!! -- >>>>>>>>>> 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
