Scala example source code file (LinkedList.scala)

This example Scala source code file (LinkedList.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, canbuildfrom, genericcompanion, generictraversabletemplate, linkedlist, linkedlistlike, low-level, mutablelist, seqfactory, serializable

The LinkedList.scala Scala example source code

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



package scala
package collection
package mutable

import generic._

/** A more traditional/primitive style of linked list where the "list" is also the "head" link. Links can be manually
  * created and manipulated, though the use of the API, when possible, is recommended.
  *
  * The danger of directly manipulating next:
  * {{{
  *     scala> val b = LinkedList(1)
  *     b: scala.collection.mutable.LinkedList[Int] = LinkedList(1)
  *
  *     scala> b.next = null
  *
  *     scala> println(b)
  *     java.lang.NullPointerException
  * }}}
  *
  *  $singleLinkedListExample
  *
  *  @author Matthias Zenger
  *  @author Martin Odersky
  *  @version 2.8
  *  @since   1
  *  @see [[http://docs.scala-lang.org/overviews/collections/concrete-mutable-collection-classes.html#linked_lists "Scala's Collection Library overview"]]
  *  section on `Linked Lists` for more information.
  *
  *  @tparam A     the type of the elements contained in this linked list.
  *
  *  @constructor Creates an "empty" list, defined as a single node with no data element and next pointing to itself.

  *  @define Coll `LinkedList`
  *  @define coll linked list
  *  @define thatinfo the class of the returned collection. In the standard library configuration,
  *    `That` is always `LinkedList[B]` because an implicit of type `CanBuildFrom[LinkedList, B, LinkedList[B]]`
  *    is defined in object `LinkedList`.
  *  @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 `LinkedList`.
  *  @define orderDependent
  *  @define orderDependentFold
  *  @define mayNotTerminateInf
  *  @define willNotTerminateInf
  *  @define collectExample Example:
  *  {{{
  *    scala>     val a = LinkedList(1, 2, 3)
  *    a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3)
  *
  *    scala>     val addOne: PartialFunction[Any, Float] = {case i: Int => i + 1.0f}
  *    addOne: PartialFunction[Any,Float] = <function1>
  *
  *    scala>     val b = a.collect(addOne)
  *    b: scala.collection.mutable.LinkedList[Float] = LinkedList(2.0, 3.0, 4.0)
  *
  *    scala> val c = LinkedList('a')
  *    c: scala.collection.mutable.LinkedList[Char] = LinkedList(a)
  *
  *    scala> val d = a ++ c
  *    d: scala.collection.mutable.LinkedList[AnyVal] = LinkedList(1, 2, 3, a)
  *
  *    scala> val e = d.collect(addOne)
  *    e: scala.collection.mutable.LinkedList[Float] = LinkedList(2.0, 3.0, 4.0)
  *  }}}
  */
@SerialVersionUID(-7308240733518833071L)
@deprecated("Low-level linked lists are deprecated due to idiosyncracies in interface and incomplete features.", "2.11.0")
class LinkedList[A]() extends AbstractSeq[A]
                         with LinearSeq[A]
                         with GenericTraversableTemplate[A, LinkedList]
                         with LinkedListLike[A, LinkedList[A]]
                         with Serializable {
  next = this

  /** Creates a new list. If the parameter next is null, the result is an empty list. Otherwise, the result is
   * a list with elem at the head, followed by the contents of next.
   *
   * Note that next is part of the new list, as opposed to the +: operator,
   * which makes a new copy of the original list.
   *
   * @example
   * {{{
   *     scala> val m = LinkedList(1)
   *     m: scala.collection.mutable.LinkedList[Int] = LinkedList(1)
   *
   *     scala> val n = new LinkedList[Int](2, m)
   *     n: scala.collection.mutable.LinkedList[Int] = LinkedList(2, 1)
   * }}}
   */
  def this(elem: A, next: LinkedList[A]) {
    this()
    if (next != null) {
      this.elem = elem
      this.next = next
    }
  }

  override def companion: GenericCompanion[LinkedList] = LinkedList
}

/** $factoryInfo
 *  @define Coll `LinkedList`
 *  @define coll linked list
 */
@deprecated("Low-level linked lists are deprecated.", "2.11.0")
object LinkedList extends SeqFactory[LinkedList] {
  override def empty[A]: LinkedList[A] = new LinkedList[A]
  implicit def canBuildFrom[A]: CanBuildFrom[Coll, A, LinkedList[A]] = ReusableCBF.asInstanceOf[GenericCanBuildFrom[A]]

  def newBuilder[A]: Builder[A, LinkedList[A]] =
    (new MutableList) mapResult ((l: MutableList[A]) => l.toLinkedList)
}