Examples for zipN, zipWithN and zipAll (#28510)

akka-docs/src/test/scala/docs/stream/operators/source/Zip.scala

@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2009-2020 Lightbend Inc. <https://www.lightbend.com>
+ */
+
+package docs.stream.operators.source
+
+import akka.NotUsed
+import akka.actor.typed.ActorSystem
+import akka.stream.scaladsl.Source
+
+object Zip {
+
+  implicit val system: ActorSystem[_] = ???
+
+  def zipN(): Unit = {
+    // #zipN-simple
+    val chars = Source("a" :: "b" :: "c" :: "e" :: "f" :: Nil)
+    val numbers = Source(1 :: 2 :: 3 :: 4 :: 5 :: 6 :: Nil)
+    val colors = Source("red" :: "green" :: "blue" :: "yellow" :: "purple" :: Nil)
+
+    Source.zipN(chars :: numbers :: colors :: Nil).runForeach(println)
+    // prints:
+    // Vector(a, 1, red)
+    // Vector(b, 2, green)
+    // Vector(c, 3, blue)
+    // Vector(e, 4, yellow)
+    // Vector(f, 5, purple)
+
+    // #zipN-simple
+  }
+
+  def zipNWith(): Unit = {
+    // #zipWithN-simple
+    val numbers = Source(1 :: 2 :: 3 :: 4 :: 5 :: 6 :: Nil)
+    val otherNumbers = Source(5 :: 2 :: 1 :: 4 :: 10 :: 4 :: Nil)
+    val andSomeOtherNumbers = Source(3 :: 7 :: 2 :: 1 :: 1 :: Nil)
+
+    Source
+      .zipWithN((seq: Seq[Int]) => seq.max)(numbers :: otherNumbers :: andSomeOtherNumbers :: Nil)
+      .runForeach(println)
+    // prints:
+    // 5
+    // 7
+    // 3
+    // 4
+    // 10
+
+    // #zipWithN-simple
+  }
+
+  def zipAll() {
+    // #zipAll-simple
+    val numbers = Source(1 :: 2 :: 3 :: 4 :: Nil)
+    val letters = Source("a" :: "b" :: "c" :: Nil)
+
+    numbers.zipAll(letters, -1, "default").runForeach(println)
+    // prints:
+    // (1,a)
+    // (2,b)
+    // (3,c)
+    // (4,default)
+    // #zipAll-simple
+  }
+}