Question

I am a very new bie for scala. So I download the source code AKKA and install the plugin for eclipse (2.7.7 final). When I open the project, it shows 29 compile errors. I know it may be version mismatch or plugin setting issue. But I don’t know how to trouble shoot it.

a) ‘)’ expected but ‘=’ found.:

case class HotSwap(code: ActorRef ⇒ Actor.Receive, discardOld: Boolean = true)

b) identifier expected but ‘object’ found.

package object actor

Can anyone help this simple question?

Thanks a lot:)

UPDATE:

A similiar question is asked by jilen.

How to add sbteclipse plugin to SBT 0.10.x

Answer 1

Default parameters do not exist in Scala 2.7.

You can fake them (sometimes sanely) though:

// Note no "= true" which specified the default value
case class HotSwap(code: Any, discardOld: Boolean)
object HotSwap {
  def apply(code: Any): HotSwap = HotSwap(code, true)
}    
>> defined class HotSwap
>> defined module HotSwap    
HotSwap("x")    
>> res1: HotSwap = HotSwap(x,true)    
HotSwap("x",false)    
>> res2: HotSwap = HotSwap(x,false)

The second set of errors is because Package Objects were also introduced in Scala 2.8. I have never dealt with them, though. “Fixing” this likely requires a good bit more work on updating references, but see previous.

Happy coding.