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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2009, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala.collection.generic
/** This extensible class may be used as a basis for implementing double
* linked lists. Type variable <code>A</code> refers to the element type
* of the list, type variable <code>This</code> is used to model self
* types of linked lists.
*
* @author Matthias Zenger
* @version 1.0, 08/07/2003
*/
trait DoubleLinkedListTemplate[A, This >: Null <: LinearSequence[A] with DoubleLinkedListTemplate[A, This]] extends LinkedListTemplate[A, This] { self =>
var prev: This = _
override def append(that: This): Unit =
if (next eq null) {
next = that
if (that ne null) that.prev = thisCollection
} else
next.append(that)
override def insert(that: This): Unit = if (that ne null) {
that.append(next)
next = that
that.prev = thisCollection
}
def remove() {
if (next ne null)
next.prev = prev
if (prev ne null)
prev.next = next
prev = null
next = null
}
}
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