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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2009, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala.collection
package mutable
import generic._
import Predef._
/** This class implements mutable maps using a hashtable.
*
* @author Matthias Zenger
* @author Martin Odersky
* @version 2.8
* @since 2.7
*/
object LinkedHashMap extends MutableMapFactory[LinkedHashMap] {
implicit def builderFactory[A, B]: BuilderFactory[(A, B), LinkedHashMap[A, B], Coll] = new MapBuilderFactory[A, B]
def empty[A, B] = new LinkedHashMap[A, B]
}
/**
* @since 2.7
*/
@serializable
class LinkedHashMap[A, B] extends Map[A, B]
with MapLike[A, B, LinkedHashMap[A, B]]
with HashTable[A] {
override def empty = LinkedHashMap.empty[A, B]
override def size = super[HashTable].size
type Entry = LinkedEntry[A, B]
protected var firstEntry: Entry = null
protected var lastEntry: Entry = null
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) {
val e = new Entry(key, value)
addEntry(e)
if (firstEntry == null) firstEntry = e
else { lastEntry.later = e; e.earlier = lastEntry }
lastEntry = e
None
} else {
val v = e.value
e.value = value
Some(v)
}
}
override def remove(key: A): Option[B] = {
val e = removeEntry(key)
if (e eq null) None
else {
if (e.earlier eq null) firstEntry = e.later
else e.earlier.later = e.later
if (e.later eq null) lastEntry = e.earlier
else e.later.earlier = e.earlier
Some(e.value)
}
}
def += (kv: (A, B)): this.type = { put(kv._1, kv._2); this }
def -=(key: A): this.type = { remove(key); this }
def iterator: Iterator[(A, B)] = new Iterator[(A, B)] {
private var cur = firstEntry
def hasNext = cur ne null
def next =
if (hasNext) { val res = (cur.key, cur.value); cur = cur.later; res }
else Iterator.empty.next
}
override def keysIterator: Iterator[A] = new Iterator[A] {
private var cur = firstEntry
def hasNext = cur ne null
def next =
if (hasNext) { val res = cur.key; cur = cur.later; res }
else Iterator.empty.next
}
override def valuesIterator: Iterator[B] = new Iterator[B] {
private var cur = firstEntry
def hasNext = cur ne null
def next =
if (hasNext) { val res = cur.value; cur = cur.later; res }
else Iterator.empty.next
}
override def foreach[U](f: ((A, B)) => U) = {
var cur = firstEntry
while (cur ne null) {
f((cur.key, cur.value))
cur = cur.later
}
}
override def clear() {
super[HashTable].clear()
firstEntry = null
}
}
|
