Scala example source code file (Map.scala)

This example Scala source code file (Map.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, boolean, map, option

The Map.scala Scala example source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2010-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

package scala
package collection.concurrent

/** A template trait for mutable maps that allow concurrent access.
 *
 *  $concurrentmapinfo
 *
 *  @since 2.8
 *  @see [[http://docs.scala-lang.org/overviews/collections/concrete-mutable-collection-classes.html#concurrent_maps "Scala's Collection Library overview"]]
 *  section on `Concurrent Maps` for more information.
 *
 *  @tparam A  the key type of the map
 *  @tparam B  the value type of the map
 *
 *  @define Coll `ConcurrentMap`
 *  @define coll concurrent map
 *  @define concurrentmapinfo
 *  This is a base trait for all Scala concurrent map implementations. It
 *  provides all of the methods a `Map` does, with the difference that all the
 *  changes are atomic. It also describes methods specific to concurrent maps.
 *
 *  '''Note''': The concurrent maps do not accept `'''null'''` for keys or values.
 *
 *  @define atomicop
 *  This is an atomic operation.
 */
trait Map[A, B] extends scala.collection.mutable.Map[A, B] {

  /**
   * Associates the given key with a given value, unless the key was already
   * associated with some other value.
   *
   * $atomicop
   *
   * @param k   key with which the specified value is to be associated with
   * @param v   value to be associated with the specified key
   * @return    `Some(oldvalue)` if there was a value `oldvalue` previously
   *            associated with the specified key, or `None` if there was no
   *            mapping for the specified key
   */
  def putIfAbsent(k: A, v: B): Option[B]

  /**
   * Removes the entry for the specified key if its currently mapped to the
   * specified value.
   *
   * $atomicop
   *
   * @param k   key for which the entry should be removed
   * @param v   value expected to be associated with the specified key if
   *            the removal is to take place
   * @return    `true` if the removal took place, `false` otherwise
   */
  def remove(k: A, v: B): Boolean

  /**
   * Replaces the entry for the given key only if it was previously mapped to
   * a given value.
   *
   * $atomicop
   *
   * @param k         key for which the entry should be replaced
   * @param oldvalue  value expected to be associated with the specified key
   *                  if replacing is to happen
   * @param newvalue  value to be associated with the specified key
   * @return          `true` if the entry was replaced, `false` otherwise
   */
  def replace(k: A, oldvalue: B, newvalue: B): Boolean

  /**
   * Replaces the entry for the given key only if it was previously mapped
   * to some value.
   *
   * $atomicop
   *
   * @param k   key for which the entry should be replaced
   * @param v   value to be associated with the specified key
   * @return    `Some(v)` if the given key was previously mapped to some value `v`, or `None` otherwise
   */
  def replace(k: A, v: B): Option[B]
}