Scala example source code file (MapProxy.scala)

This example Scala source code file (MapProxy.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, b1, boolean, c, gentraversableonce, map, mapproxy, proxying, setproxy

The MapProxy.scala Scala example source code

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



package scala
package collection
package immutable

/**
 *  This is a simple wrapper class for <a href="Map.html"
 *  target="contentFrame">`scala.collection.immutable.Map`</a>.
 *
 *  It is most useful for assembling customized map abstractions
 *  dynamically using object composition and forwarding.
 *
 *  @author  Matthias Zenger, Martin Odersky
 *  @version 2.0, 31/12/2006
 *  @since   2.8
 */
@deprecated("Proxying is deprecated due to lack of use and compiler-level support.", "2.11.0")
trait MapProxy[A, +B] extends Map[A, B] with MapProxyLike[A, B, Map[A, B]] {
  override def repr = this
  private def newProxy[B1 >: B](newSelf: Map[A, B1]): MapProxy[A, B1] =
    new MapProxy[A, B1] { val self = newSelf }

  override def empty = newProxy(self.empty)
  override def updated [B1 >: B](key: A, value: B1) = newProxy(self.updated(key, value))

  override def -(key: A) = newProxy(self - key)
  override def + [B1 >: B](kv: (A, B1)): Map[A, B1] = newProxy(self + kv)
  override def + [B1 >: B](elem1: (A, B1), elem2: (A, B1), elems: (A, B1) *) = newProxy(self.+(elem1, elem2, elems: _*))
  override def ++[B1 >: B](xs: GenTraversableOnce[(A, B1)]) = newProxy(self ++ xs.seq)

  override def keySet: immutable.Set[A] = new SetProxy[A] { val self = MapProxy.this.self.keySet }
  override def filterKeys(p: A => Boolean) = self.filterKeys(p)
  override def mapValues[C](f: B => C) = self.mapValues(f)
}