Question

As I understand it, when they finally come along, we will be able to substitute a Java closure for the equivalent single-method interface. Is there a standard Scala idiom for doing the same – implementing a Java Single Abstract Method interface with a Scala closure?

Ideally I’d like the following to automagically work

test("Closure") {
  var event: PropertyChangeEvent = null
  var label = new JLabel()
  label.addPropertyChangeListener( {e: PropertyChangeEvent => event = e} )
  label.setText("fred")
  event.getNewValue should be ("fred")
}

Answer 1

There was a lengthy discussion about this in January.

http://www.scala-lang.org/node/8744

The idea was well received, and even taken a bit further than this proposal. But the devil is in the details, and a prototype implementation may yet find other problems with this proposal.