Scala example source code file (fail6.scala)

This example Scala source code file (fail6.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

boolean, boolean, erasure, erasure

The Scala fail6.scala source code

// BoxedUnit/Unit confusion involving while.
//
// Apply( // sym=method while$1, tpe=Unit, tpe.sym=class Unit, tpe.sym.owner=package scala
//   Ident("while$1"), // sym=method while$1, sym.owner=method f, sym.tpe=()Unit, tpe=()Unit, tpe.sym=<none>,
class Erasure {
  def f(b: Boolean) = {    
    if (b) "abc"
    else while (b) ()
  }
}

// % work/check all -Xprint:erasure work/fail6.scala  
// TypeStack init: REFERENCE(type AnyRef)
// [Not checkable: parser]
// [Not checkable: namer]
// [Not checkable: packageobjects]
// [Now checking: typer]
// [Now checking: superaccessors]
// [Now checking: pickler]
// [Now checking: refchecks]
// [Now checking: selectiveanf]
// [Now checking: liftcode]
// [Now checking: selectivecps]
// [Now checking: uncurry]
// [Now checking: tailcalls]
// [Not checkable: specialize]
// [Not checkable: explicitouter]
// [[syntax trees at end of erasure]]// Scala source: fail6.scala
// package <empty> {
//   class Erasure extends java.lang.Object with ScalaObject {
//     def this(): Erasure = {
//       Erasure.super.this();
//       ()
//     };
//     def f(b: Boolean): java.lang.Object = if (b)
//       "abc"
//     else
//       while$1(){
//         if (b)
//           {
//             ();
//             while$1()
//           }
//         else
//           ();
//         scala.runtime.BoxedUnit.UNIT
//       }
//   }
// }
// 
// [Now checking: erasure]
// work/fail6.scala:4: error: 
// **** ERROR DURING INTERNAL CHECKING ****
// type mismatch;
//  found   : scala.runtime.BoxedUnit
//  required: Unit
//     else while (b) ()
//          ^
// one error found
// 
//