[Akka streams] Why is there no GraphStage in akka streams that can give me a failed element along with throwable ?

[Saloni Vithalani]

Hello,

Let's say for example we have such a stream

Source(1 to 10)
  .map(x ⇒ if (x % 2 == 0) throw new RuntimeException("test error"))
  .mapError {
    case NonFatal(ex) ⇒
      // do something with the failed element 2
      ex.printStackTrace()
      ex
  }

The question is why not mapError give me element '2' along with the 'RuntimeException' ?