             self.push(Cell.Literal(value: address))
 
         default:
-            println("problem: \(currentItem.description())")
+            println("problem: \(currentItem)")
         }
     }
 

    case Variable(address: Int)
    case Constant(value: Int)

    func description() -> String {
        switch self {
        case let .Thread(index):
            return "Thread(\(index))"

    }

    func printTopOfStackPrim() {
        print("\(self.pop()) ")
        self.next()
    }

