[akka-user] Re: Akka Streams Merge variance
Thanks Johannes, didn't realize the inlets have different variance to the merge. -- 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.
Re: [akka-user] Re: Akka Streams Merge variance
Thinking about it perhaps it makes sense to have a MergeWith, where Merge is using the identity function? -- Cheers, √ On 19 May 2015 02:10, Andrey Kuznetsov f...@loathing.in wrote: I asked myself the same question when I faced to the problem of merging elements from Source[A] and Source[B] where A and B are children of the same trait C. Had to make both sources a Source[C]. On Saturday, May 16, 2015 at 4:47:51 PM UTC+3, Oliver Winks wrote: If you look at the implementation of Merge you find that it is a generic type, but without any defined variance: classMerge[T] extends Graph http://doc.akka.io/api/akka-stream-and-http-experimental/1.0-RC2/akka/stream/Graph.html [UniformFanInShape http://doc.akka.io/api/akka-stream-and-http-experimental/1.0-RC2/akka/stream/UniformFanInShape.html [T, T], Unit http://www.scala-lang.org/api/2.10.5/index.html#scala.Unit ] Is there any reason for this? Would it not make sense to define it as a covariant type? e.g: classMerge[+T] extends Graph http://doc.akka.io/api/akka-stream-and-http-experimental/1.0-RC2/akka/stream/Graph.html [UniformFanInShape http://doc.akka.io/api/akka-stream-and-http-experimental/1.0-RC2/akka/stream/UniformFanInShape.html [T, T], Unit http://www.scala-lang.org/api/2.10.5/index.html#scala.Unit ] -- 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.
[akka-user] Re: Akka Streams Merge variance
I asked myself the same question when I faced to the problem of merging elements from Source[A] and Source[B] where A and B are children of the same trait C. Had to make both sources a Source[C]. On Saturday, May 16, 2015 at 4:47:51 PM UTC+3, Oliver Winks wrote: If you look at the implementation of Merge you find that it is a generic type, but without any defined variance: classMerge[T] extends Graph http://doc.akka.io/api/akka-stream-and-http-experimental/1.0-RC2/akka/stream/Graph.html [UniformFanInShape http://doc.akka.io/api/akka-stream-and-http-experimental/1.0-RC2/akka/stream/UniformFanInShape.html [T, T], Unit http://www.scala-lang.org/api/2.10.5/index.html#scala.Unit] Is there any reason for this? Would it not make sense to define it as a covariant type? e.g: classMerge[+T] extends Graph http://doc.akka.io/api/akka-stream-and-http-experimental/1.0-RC2/akka/stream/Graph.html [UniformFanInShape http://doc.akka.io/api/akka-stream-and-http-experimental/1.0-RC2/akka/stream/UniformFanInShape.html [T, T], Unit http://www.scala-lang.org/api/2.10.5/index.html#scala.Unit] -- 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.
