scala.collection.mutable.DoubleLinkedList.scala Maven / Gradle / Ivy
/*
* Scala (https://www.scala-lang.org)
*
* Copyright EPFL and Lightbend, Inc.
*
* Licensed under Apache License 2.0
* (http://www.apache.org/licenses/LICENSE-2.0).
*
* See the NOTICE file distributed with this work for
* additional information regarding copyright ownership.
*/
package scala
package collection
package mutable
import generic._
/** This class implements double linked lists where both the head (`elem`),
* the tail (`next`) and a reference to the previous node (`prev`) are mutable.
*
* @author Matthias Zenger
* @author Martin Odersky
* @since 1
* @see [[http://docs.scala-lang.org/overviews/collections/concrete-mutable-collection-classes.html#double-linked-lists "Scala's Collection Library overview"]]
* section on `Double Linked Lists` for more information.
*
* @tparam A the type of the elements contained in this double linked list.
*
* @define Coll `DoubleLinkedList`
* @define coll double linked list
* @define thatinfo the class of the returned collection. In the standard library configuration,
* `That` is always `DoubleLinkedList[B]` because an implicit of type `CanBuildFrom[DoubleLinkedList, B, DoubleLinkedList[B]]`
* is defined in object `DoubleLinkedList`.
* @define bfinfo an implicit value of class `CanBuildFrom` which determines the
* result class `That` from the current representation type `Repr`
* and the new element type `B`. This is usually the `canBuildFrom` value
* defined in object `DoubleLinkedList`.
* @define orderDependent
* @define orderDependentFold
* @define mayNotTerminateInf
* @define willNotTerminateInf
*/
@deprecated("low-level linked lists are deprecated due to idiosyncrasies in interface and incomplete features", "2.11.0")
@SerialVersionUID(-8144992287952814767L)
class DoubleLinkedList[A]() extends AbstractSeq[A]
with LinearSeq[A]
with GenericTraversableTemplate[A, DoubleLinkedList]
with DoubleLinkedListLike[A, DoubleLinkedList[A]]
with Serializable {
next = this
/** Creates a node for the double linked list.
*
* @param elem the element this node contains.
* @param next the next node in the double linked list.
*/
def this(elem: A, next: DoubleLinkedList[A]) {
this()
if (next != null) {
this.elem = elem
this.next = next
this.next.prev = this
}
}
override def companion: GenericCompanion[DoubleLinkedList] = DoubleLinkedList
// Accurately clone this collection. See scala/bug#6296
override def clone(): DoubleLinkedList[A] = {
val builder = newBuilder
builder ++= this
builder.result()
}
}
/** $factoryInfo
* @define coll double linked list
* @define Coll `DoubleLinkedList`
*/
@deprecated("low-level linked lists are deprecated", "2.11.0")
object DoubleLinkedList extends SeqFactory[DoubleLinkedList] {
/** $genericCanBuildFromInfo */
implicit def canBuildFrom[A]: CanBuildFrom[Coll, A, DoubleLinkedList[A]] = ReusableCBF.asInstanceOf[GenericCanBuildFrom[A]]
def newBuilder[A]: Builder[A, DoubleLinkedList[A]] =
new Builder[A, DoubleLinkedList[A]] {
def emptyList() = new DoubleLinkedList[A]()
var current = emptyList()
def +=(elem: A): this.type = {
if (current.isEmpty)
current = new DoubleLinkedList(elem, emptyList())
else
current append new DoubleLinkedList(elem, emptyList())
this
}
def clear(): Unit = current = emptyList()
def result() = current
}
}