Are Errors in a Future body rethrown, as per the documentation?

Hi all

With regard to the handling of Errors, the "Futures and Promises" 
documentation [1] states:

ExecutionException - stored when the computation fails due to an unhandled 
> InterruptedException, Error or a scala.util.control.ControlThrowable. In 
> this case the ExecutionException has the unhandled exception as its 
> cause. *These exceptions are rethrown in the thread executing the failed 
> asynchronous computation.*


Is this latter statement true in general, e.g. also if you supply your own 
ExecutionContext? Or does it depend on the ExecutionContext implementation?

In this example at least, nothing seems to be rethrown (or passed to 
reportFailure, for that matter):

Welcome to Scala version 2.11.6 (Java HotSpot(TM) 64-Bit Server VM, Java 
1.7.0_40).


import scala.concurrent.Future
import scala.concurrent.ExecutionContext
import scala.util.{Failure, Success}


implicit object SameThreadExecutionContext extends ExecutionContext {
  override def execute(runnable: Runnable): Unit = {
    println("DEBUG: running " + runnable)
    runnable.run()
  }
  override def reportFailure(t: Throwable): Unit = ??? // never called?
}

scala> Future { throw new Error("bang!") }.value
DEBUG: running 
scala.concurrent.impl.Future$PromiseCompletingRunnable@887b5d0
res1: Option[scala.util.Try[Nothing]] = 
Some(Failure(java.util.concurrent.ExecutionException: Boxed Error))


Am I missing something or misreading the docs here?

Regards

ap

[1] http://docs.scala-lang.org/overviews/core/futures.html#exceptions

-- 
You received this message because you are subscribed to the Google Groups "scala-language" group.
To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
For more options, visit https://groups.google.com/d/optout.