akka.stream.scaladsl.Materialization.scala Maven / Gradle / Ivy
/*
* Copyright (C) 2015-2020 Lightbend Inc.
*/
package akka.stream.scaladsl
import akka.NotUsed
/**
* Convenience functions for often-encountered purposes like keeping only the
* left (first) or only the right (second) of two input values.
*/
object Keep {
private val _left = (l: Any, _: Any) => l
private val _right = (_: Any, r: Any) => r
private val _both = (l: Any, r: Any) => (l, r)
private val _none = (_: Any, _: Any) => NotUsed
def left[L, R]: (L, R) => L = _left.asInstanceOf[(L, R) => L]
def right[L, R]: (L, R) => R = _right.asInstanceOf[(L, R) => R]
def both[L, R]: (L, R) => (L, R) = _both.asInstanceOf[(L, R) => (L, R)]
def none[L, R]: (L, R) => NotUsed = _none.asInstanceOf[(L, R) => NotUsed]
}