tryTake

abstract fun tryTake(): Kind<F, Option<A>>

Attempts to take a value from the Queue if one is available, this method is guaranteed not to semantically block. It returns immediately an Option with either None or a value wrapped in Some.

import arrow.fx.*
import arrow.fx.extensions.fx

//sampleStart
suspend fun main(args: Array<String>): Unit = IO.fx {
  val queue = !Queue.unbounded<Int>()
  val none = !queue.tryTake()
  !queue.offer(1)
  val one = !queue.tryTake()
  val none2 = !queue.tryTake()
  !effect { println("none: $none, one $one, none2: $none2") }
}.suspended()
//sampleEnd

See Also

take

tryPeek