Scala example source code file (WeakHashMap.scala)

This example Scala source code file (WeakHashMap.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

a, b, canbuildfrom, jmapwrapper, jmapwrapperlike, mapcanbuildfrom, mutablemapfactory, weakhashmap

The WeakHashMap.scala Scala example source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

package scala
package collection
package mutable

import generic._
import convert.Wrappers._

/** A hash map with references to entries which are weakly reachable. Entries are
 *  removed from this map when the key is no longer (strongly) referenced. This class wraps
 *  `java.util.WeakHashMap`.
 *
 *  @tparam A      type of keys contained in this map
 *  @tparam B      type of values associated with the keys
 *
 *  @since 2.8
 *  @see [[http://docs.scala-lang.org/overviews/collections/concrete-mutable-collection-classes.html#weak_hash_maps "Scala's Collection Library overview"]]
 *  section on `Weak Hash Maps` for more information.
 *
 *  @define Coll `WeakHashMap`
 *  @define coll weak hash map
 *  @define thatinfo the class of the returned collection. In the standard library configuration,
 *    `That` is always `WeakHashMap[A, B]` if the elements contained in the resulting collection are
 *    pairs of type `(A, B)`. This is because an implicit of type `CanBuildFrom[WeakHashMap, (A, B), WeakHashMap[A, B]]`
 *    is defined in object `WeakHashMap`. Otherwise, `That` resolves to the most specific type that doesn't have
 *    to contain pairs of type `(A, B)`, which is `Iterable`.
 *  @define bfinfo an implicit value of class `CanBuildFrom` which determines the
 *    result class `That` from the current representation type `Repr`
 *    and the new element type `B`. This is usually the `canBuildFrom` value
 *    defined in object `WeakHashMap`.
 *  @define mayNotTerminateInf
 *  @define willNotTerminateInf
 */
class WeakHashMap[A, B] extends JMapWrapper[A, B](new java.util.WeakHashMap)
			   with JMapWrapperLike[A, B, WeakHashMap[A, B]] {
  override def empty = new WeakHashMap[A, B]
}

/** $factoryInfo
 *  @define Coll `WeakHashMap`
 *  @define coll weak hash map
 */
object WeakHashMap extends MutableMapFactory[WeakHashMap] {
  implicit def canBuildFrom[A, B]: CanBuildFrom[Coll, (A, B), WeakHashMap[A, B]] = new MapCanBuildFrom[A, B]
  def empty[A, B]: WeakHashMap[A, B] = new WeakHashMap[A, B]
}