Scala delimited continuations error at runtime - scala

Question

Scala newbie here, I just downloaded Eclipse 3.6.2 and Scala IDE 2.0.0-beta4 (with Scala 2.9.0.final). I create a new Scala project to try delimited continuations:
package delimCCTests
import scala.util.continuations._
object Test extends App {
val result = reset {
1 + shift { k: (Int => Int) => k(k(5)) } + 1
}
println(result)
}
This compiles fine, then I click Run as -> Scala application and get this exception:
Exception in thread "main" java.lang.NoSuchMethodError: scala.util.continuations.package$.shift(Lscala/Function1;)Ljava/lang/Object;
at delimCCTests.Test$$anonfun$1.apply$mcI$sp(DelimCCTests.scala:7)
at delimCCTests.Test$$anonfun$1.apply(DelimCCTests.scala:7)
at delimCCTests.Test$$anonfun$1.apply(DelimCCTests.scala:7)
at scala.util.continuations.package$.reset(package.scala:20)
at delimCCTests.Test$delayedInit$body.apply(DelimCCTests.scala:6)
at scala.Function0$class.apply$mcV$sp(Function0.scala:34)
at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)
at scala.App$$anonfun$main$1.apply(App.scala:60)
at scala.App$$anonfun$main$1.apply(App.scala:60)
at scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:59)
at scala.collection.immutable.List.foreach(List.scala:45)
at scala.collection.generic.TraversableForwarder$class.foreach(TraversableForwarder.scala:30)
at scala.App$class.main(App.scala:60)
at delimCCTests.Test$.main(DelimCCTests.scala:5)
at delimCCTests.Test.main(DelimCCTests.scala)
What am I doing wrong? Am I missing some configuration?
BTW I thought the compiler inferred the type of the continuation? This article uses:
val result = reset {
1 + shift { k => k(k(5)) } + 1
}
but this doesn't compile in my environment...

Answer 1

This error means that you didn't add Scala CPS plugin - it's not a part of a standard assembly (so far). Put the jar on the classpath, and run Scala is follows, in order to have continuations enabled:
$ scala -P:continuations:enable

Answer 2

This can be solved in eclipse by adding the CPS plugins class on the Scala Compiler > Advanced section, as well as enabling the switch:
Xplugin should be scala.tools.selectivecps.SelectiveCPSPlugin and Xpluginsdir should be the dir which contains org.scala-lang.plugins.scala-continuations-plugin.jar