/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2011, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala.collection
package mutable
import generic._
/** A base trait for maps that can be mutated.
* $mapNote
* $mapTags
* @since 1.0
* @author Matthias Zenger
*/
trait Map[A, B]
extends Iterable[(A, B)]
with scala.collection.Map[A, B]
with MapLike[A, B, Map[A, B]] {
override def empty: Map[A, B] = Map.empty
/** The same map with a given default function.
*
* Invoking transformer methods (e.g. `map`) will not preserve the default value.
*
* @param d the function mapping keys to values, used for non-present keys
* @return a wrapper of the map with a default value
*/
def withDefault(d: A => B): mutable.Map[A, B] = new Map.WithDefault[A, B](this, d)
/** The same map with a given default value.
*
* Invoking transformer methods (e.g. `map`) will not preserve the default value.
*
* @param d the function mapping keys to values, used for non-present keys
* @return a wrapper of the map with a default value
*/
def withDefaultValue(d: B): mutable.Map[A, B] = new Map.WithDefault[A, B](this, x => d)
/** Return a read-only projection of this map. !!! or just use an (immutable) MapProxy?
def readOnly : scala.collection.Map[A, B] = new scala.collection.Map[A, B] {
override def size = self.size
override def update(key: A, value: B) = self.update(key, value)
override def - (elem: A) = self - elem
override def iterator = self.iterator
override def foreach[U](f: ((A, B)) => U) = self.foreach(f)
override def empty[C] = self.empty[C]
def get(key: A) = self.get(key)
}
*/
}
/** $factoryInfo
* The current default implementation of a $Coll is a `HashMap`.
* @define coll mutable map
* @define Coll mutable.Map
*/
object Map extends MutableMapFactory[Map] {
/** $canBuildFromInfo */
implicit def canBuildFrom[A, B]: CanBuildFrom[Coll, (A, B), Map[A, B]] = new MapCanBuildFrom[A, B]
def empty[A, B]: Map[A, B] = new HashMap[A, B]
class WithDefault[A, B](underlying: Map[A, B], d: A => B) extends collection.Map.WithDefault(underlying, d) with Map[A, B] {
override def += (kv: (A, B)) = {underlying += kv; this}
def -= (key: A) = {underlying -= key; this}
override def empty = new WithDefault(underlying.empty, d)
override def updated[B1 >: B](key: A, value: B1): WithDefault[A, B1] = new WithDefault[A, B1](underlying.updated[B1](key, value), d)
override def + [B1 >: B](kv: (A, B1)): WithDefault[A, B1] = updated(kv._1, kv._2)
override def - (key: A): WithDefault[A, B] = new WithDefault(underlying - key, d)
/** If these methods aren't overridden to thread through the underlying map,
* successive calls to withDefault* have no effect.
*/
override def withDefault(d: A => B): mutable.Map[A, B] = new WithDefault[A, B](underlying, d)
override def withDefaultValue(d: B): mutable.Map[A, B] = new WithDefault[A, B](underlying, x => d)
}
}
