Scala example source code file (t3079.scala)

This example Scala source code file (t3079.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

a, a, b, b, coerce, coerce, identity, identity, identitycoerce

The Scala t3079.scala source code

sealed trait Identity[A] {
  val value: A
}

trait Coerce[A, B] {
  def unwrap: (A => B)
}

object Coerce {
  def IdentityCoerce[B] = new Coerce[Identity[B], B] {
     // java.lang.Error: A in trait Identity cannot be instantiated from ?x$1.type
     def unwrap = _.value
     
     // Providing the type of _ works around the problem.
     //def unwrap = (_: Identity[B]).value 
  }
}