Scala example source code file (spec-super.scala)

This example Scala source code file (spec-super.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, base, base, canbuildfrom, derived, that, that, traversable, traversable

The Scala spec-super.scala source code

import scala.collection.immutable._
import scala.collection.mutable.ListBuffer
import scala.collection.generic._

trait Base[+A] extends Traversable[A] {
  def add[B >: A, That](that: Traversable[B])(implicit bf: CanBuildFrom[Base[A], B, That]): That = {
    val b = bf(this)
    b ++= this
    b ++= that
    b.result
  }

}

abstract class Derived[@specialized +A] extends Base[A] {
  override def add[B >: A, That](that: Traversable[B])(implicit bf: CanBuildFrom[Base[A], B, That]): That = {
    val b = bf(this)
    super.add[B, That](that)
  }
}