Bug in Stream-Graphs example

[ktoso]

Reported by Sergey Sopin on akka-user.

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It seems that one of examples in the documentation contains bug, namely: http://doc.akka.io/docs/akka/2.4.7/java/stream/stream-graphs.html

final Source<Integer, NotUsed> in = Source.from(Arrays.asList(1, 2, 3, 4, 5));
final Sink<List<String>, CompletionStage<List<String>>> sink = Sink.head();
final Sink<List<Integer>, CompletionStage<List<Integer>>> sink2 = Sink.head();
final Flow<Integer, Integer, NotUsed> f1 = Flow.of(Integer.class).map(elem -> elem + 10);
final Flow<Integer, Integer, NotUsed> f2 = Flow.of(Integer.class).map(elem -> elem + 20);
final Flow<Integer, String, NotUsed> f3 = Flow.of(Integer.class).map(elem -> elem.toString());
final Flow<Integer, Integer, NotUsed> f4 = Flow.of(Integer.class).map(elem -> elem + 30);

final RunnableGraph<CompletionStage<List<String>>> result =
  RunnableGraph.<CompletionStage<List<String>>>fromGraph(
    GraphDSL
      .create(
        sink,
        (builder, out) -> {
          final UniformFanOutShape<Integer, Integer> bcast = builder.add(Broadcast.create(2));
          final UniformFanInShape<Integer, Integer> merge = builder.add(Merge.create(2));

          final Outlet<Integer> source = builder.add(in).out();
          builder.from(source).via(builder.add(f1))
            .viaFanOut(bcast).via(builder.add(f2)).viaFanIn(merge)
            .via(builder.add(f3.grouped(1000))).to(out);
          builder.from(bcast).via(builder.add(f4)).toFanIn(merge);
          return ClosedShape.getInstance();
        }));

Here we define 'sink2' variable, but never use it. We are using 'out' variable instead, which is undefined.
Please fix this confusing thing when it will be possible.

Thanks,
Sergey

[gosubpl]

Actually out is a local variable for lambda function (builder, out) -> { }, it is defined as SinkShape - this is a consequence of definition of GraphDSL.create function. I will submit a PR soon that removes redundant sink2 and clarifies the role of out via a comment.

[patriknw]

@ktoso issues in docs can by definition not be bug. Let's use bug for real production issues.

[ktoso]

Right, sorry for abuse of tag