Scala example source code file (DefaultMapModel.scala)

This example Scala source code file (DefaultMapModel.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, defaultmapmodel, entry, iterator, map, none, option, some, this

The DefaultMapModel.scala Scala example source code

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



package scala
package collection
package mutable

/** This class is used internally. It implements the mutable `Map`
 *  class in terms of three functions: `findEntry`, `addEntry`, and `entries`.
 *
 *  @author  Matthias Zenger
 *  @version 1.0, 08/07/2003
 *  @since   1
 */
@deprecated("This trait will be removed.", "2.11.0")
trait DefaultMapModel[A, B] extends Map[A, B] {

  type Entry = DefaultEntry[A, B]

  protected def findEntry(key: A): Entry
  protected def addEntry(e: Entry)
  protected def entries: Iterator[Entry]

  def get(key: A): Option[B] = {
    val e = findEntry(key)
    if (e == null) None
    else Some(e.value)
  }

  override def put(key: A, value: B): Option[B] = {
    val e = findEntry(key)
    if (e == null) { addEntry(new Entry(key, value)); None }
    else { val v = e.value; e.value = value; Some(v) }
  }

  def += (kv: (A, B)): this.type = { put(kv._1, kv._2); this }

  def iterator = entries map {e => (e.key, e.value)}

}