Scala Reactive Programming

The ask (?) function

It follows the Send and Receive model, which means send a message asynchronously and return Future to retrieve results sometime in the future. It is known as the Ask pattern:

val result: Future[Result] = (actor ? message).mapTo[String] 

In the Akka Framework API, this ask pattern is defined at the akka.pattern package:

import akka.pattern.ask 
 
ask(actor, message) // use it directly 
actor ask message   // use it by implicit conversion 
actor ? message       // use it by implicit conversion