zipAll

Combines elements from two sources into tuples Pair handling early completion of either source.

Signature

Source.zipAllSource.zipAll Flow.zipAllFlow.zipAll

Description

Combines elements from two sources into tuples Pair and passes downstream. If either source completes, a default value is combined with each value from the other source until it completes.

Example

Scala

sourceval 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)

Java

source
Source<Integer, NotUsed> numbers = Source.from(Arrays.asList(1, 2, 3, 4));
Source<String, NotUsed> letters = Source.from(Arrays.asList("a", "b", "c"));

numbers.zipAll(letters, -1, "default").runForeach(System.out::println, system);
// prints:
// Pair(1,a)
// Pair(2,b)
// Pair(3,c)
// Pair(4,default)

Reactive Streams semantics

emits at first emits when both inputs emit, and then as long as any input emits (coupled to the default value of the completed input)

backpressures both upstreams when downstream backpressures but also on an upstream that has emitted an element until the other upstream has emitted an element

completes when both upstream completes