It's the wording "with merge being the preferred strategy". From your email it is clear that merge is *not* the strategy used in Akka streams, so perhaps best to drop this sentence as it confuses more than clarifies. Instead, it would be instructive to note that a Source is returned and perhaps talk about the strategy that is used. On 21 Jan 2015 09:09, "Endre Varga" <[email protected]> wrote:
> > > On Wed, Jan 21, 2015 at 10:06 AM, Sam Halliday <[email protected]> > wrote: > >> There was some discussion about merging Seq in the docs. >> > If that is so, can you point to that part? We might need to rewrite it to > clarify what it is about and what it is not. If you find it can you file a > ticket? > > Thanks, > -Endre > > > >> Anyway, it is a side point and I don't want to get derailed from my >> original questions so I will read your other responses later today. >> On 21 Jan 2015 08:50, "Endre Varga" <[email protected]> wrote: >> >>> >>> >>> On Wed, Jan 21, 2015 at 9:45 AM, Sam Halliday <[email protected]> >>> wrote: >>> >>>> Err, Endre, yes. And when merging Seq[T] in a mapConcat we would all >>>> benefit greatly from faster merging, Seq[Seq[T]] => Seq[T] >>>> >>> What do you mean? I don't understand. What mapConcat does is that it >>> takes a Source[T] and a function T => Seq[U] and gives a Source[U] >>> (similarly with Flow). Source is not a Seq, it is a completely different >>> beast. >>> >>> >>> >>>> On 21 Jan 2015 08:03, "Endre Varga" <[email protected]> wrote: >>>> >>>>> Hi Sam, >>>>> >>>>> On Tue, Jan 20, 2015 at 9:56 PM, Sam Halliday <[email protected]> >>>>> wrote: >>>>> >>>>>> One more comment on the streams API. It is really cool that you've >>>>>> thought about using mapConcat instead of flatMap to enable optimised >>>>>> merge >>>>>> operations. I just wanted to draw your attention to a clojure project >>>>>> that >>>>>> does super-fast merging of immutable Tree/Trie structures: >>>>>> https://github.com/JulesGosnell/seqspert >>>>>> >>>>> >>>>> I feel a misunderstanding here. Akka Streams is not about data >>>>> structures, it is about streams. I mean real streams, like live TCP >>>>> incoming bytes. Unfortunately Java also chose the name Stream for another >>>>> concept, but that is more targeted for collections. In Akka Streams on the >>>>> other hand streams backed by collections is the rare case, not the common >>>>> one (although many examples use collections as sources since they are easy >>>>> to show). >>>>> >>>>> -Endre >>>>> >>>>> >>>>>> The work is definitely portable to the Scala collection types, as >>>>>> they are based on the Clojure implementations. >>>>>> >>>>>> >>>>>> On Tuesday, 20 January 2015 19:04:45 UTC, Sam Halliday wrote: >>>>>>> >>>>>>> Dear Akka Team, >>>>>>> >>>>>>> In response to Bjorn's prompting[1], I have read all the Akka >>>>>>> Streams 1.0-M2 documentation[2]. >>>>>>> >>>>>>> I am very impressed, and excited! There has clearly been a lot of >>>>>>> thought put into this framework and I am looking forward to using >>>>>>> it in anger over the coming years. >>>>>>> >>>>>>> Bjorn asked if I felt any examples were missing, and sadly my >>>>>>> original request (that I've been going on about for years, >>>>>>> sorry!) is indeed missing. It is the case of a fast producer and >>>>>>> a slow consumer that is ideal for parallelisation. >>>>>>> >>>>>>> I believe it may be possible to use the current 1.0-M2 to address >>>>>>> my bugbear by using the Actor integration to write an actor that >>>>>>> has N instances behind a router, but it feels hacky to have to >>>>>>> use an Actor at all. What is really missing is a Junction that >>>>>>> multiplies the next Flow into N parallel parts that run on >>>>>>> separate threads. >>>>>>> >>>>>>> >>>>>>> In general, I felt that the documentation was missing any >>>>>>> commentary on concurrency and parallelisation. I was left >>>>>>> wondering what thread everything was happening on. Some initial >>>>>>> questions I have in this area: >>>>>>> >>>>>>> 1. Is everything actually executed in the same thread? What about >>>>>>> when you have a Junction? >>>>>>> >>>>>>> 2. Is it possible to be doing work to populate the Source's cache >>>>>>> while work is being executed in a Flow or Sink? >>>>>>> >>>>>>> It would be good to have a section in the documentation that >>>>>>> discusses this in more detail. >>>>>>> >>>>>>> >>>>>>> And, very importantly, it would be good to have the feature of >>>>>>> being able to split a Flow into N parallel parts! I recently >>>>>>> learnt how to do this in ScalazStreams but I'm much rather be >>>>>>> able to do it in Akka Streams as I find everything else about the >>>>>>> architecture to be so much easier to understand (plus integration >>>>>>> with Akka Actors is just tremendous). >>>>>>> >>>>>>> PS: I'm also very excited by Slick 3.0 which appears to be aiming >>>>>>> toward Reactive Streams and, I assume, integration with Akka Streams. >>>>>>> e.g. >>>>>>> produce a Source[Entity] from a SELECT with pushback on extremely large >>>>>>> result sets. >>>>>>> >>>>>>> >>>>>>> [1] https://groups.google.com/d/msg/akka-user/1TlAy-oqOk8/ >>>>>>> xvJpyVMWytsJ >>>>>>> [2] http://doc.akka.io/docs/akka-stream-and-http-experimental/ >>>>>>> 1.0-M2/scala.html >>>>>>> [3] https://github.com/fommil/rx-playground/blob/master/src/ >>>>>>> main/scala/com/github/fommil/rx/scratch.scala#L204 >>>>>>> >>>>>>> Best regards, >>>>>>> Sam (fommil) >>>>>>> >>>>>>> -- >>>>>> >>>>>>>>>> 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 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 a topic in the >>>>> Google Groups "Akka User List" group. >>>>> To unsubscribe from this topic, visit >>>>> https://groups.google.com/d/topic/akka-user/SYmCYGQppKw/unsubscribe. >>>>> To unsubscribe from this group and all its topics, send an email to >>>>> [email protected]. >>>>> To post to this group, send email to [email protected]. >>>>> 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 [email protected]. >>>> To post to this group, send email to [email protected]. >>>> 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 a topic in the >>> Google Groups "Akka User List" group. >>> To unsubscribe from this topic, visit >>> https://groups.google.com/d/topic/akka-user/SYmCYGQppKw/unsubscribe. >>> To unsubscribe from this group and all its topics, send an email to >>> [email protected]. >>> To post to this group, send email to [email protected]. >>> 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 [email protected]. >> To post to this group, send email to [email protected]. >> 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 a topic in the > Google Groups "Akka User List" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/akka-user/SYmCYGQppKw/unsubscribe. > To 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