contramap

Transform this Flow by applying a function to each incoming upstream element before it is passed to the Flow.

Simple operators

Signature

Flow.contramapFlow.contramap { scala=“#contramapIn2:Flow[In2, Out, Mat]” java=“#map( akka.japi.function.Function)” }

Description

Transform this Flow by applying a function to each incoming upstream element before it is passed to the Flow.

Examples

Scala

copysourceimport akka.NotUsed
import akka.stream.scaladsl._

val flow: Flow[Int, Int, NotUsed] = Flow[Int]
val newFlow: Flow[String, Int, NotUsed] = flow.contramap(_.toInt)

Reactive Streams semantics