Scala example source code file (IndexedSeq.scala)

This example Scala source code file (IndexedSeq.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, abstractseq, canbuildfrom, genericcompanion, generictraversabletemplate, impl, indexedseq, int, seq, serializable

The IndexedSeq.scala Scala example source code

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


package scala
package collection
package immutable

import generic._
import mutable.{ArrayBuffer, Builder}

/** A subtrait of `collection.IndexedSeq` which represents indexed sequences
 *  that are guaranteed immutable.
 *  $indexedSeqInfo
 */
trait IndexedSeq[+A] extends Seq[A]
                    with scala.collection.IndexedSeq[A]
                    with GenericTraversableTemplate[A, IndexedSeq]
                    with IndexedSeqLike[A, IndexedSeq[A]] {
  override def companion: GenericCompanion[IndexedSeq] = IndexedSeq
  
  /** Returns this $coll as an indexed sequence.
   *  
   *  A new indexed sequence will not be built; lazy collections will stay lazy.
   */
  @deprecatedOverriding("Immutable indexed sequences should do nothing on toIndexedSeq except cast themselves as an indexed sequence.", "2.11.0")
  override def toIndexedSeq: IndexedSeq[A] = this
  override def seq: IndexedSeq[A] = this
}

/** $factoryInfo
 *  The current default implementation of a $Coll is a `Vector`.
 *  @define coll indexed sequence
 *  @define Coll `IndexedSeq`
 */
object IndexedSeq extends IndexedSeqFactory[IndexedSeq] {
  class Impl[A](buf: ArrayBuffer[A]) extends AbstractSeq[A] with IndexedSeq[A] with Serializable {
    def length = buf.length
    def apply(idx: Int) = buf.apply(idx)
  }
  def newBuilder[A]: Builder[A, IndexedSeq[A]] = Vector.newBuilder[A]

  implicit def canBuildFrom[A]: CanBuildFrom[Coll, A, IndexedSeq[A]] =
    ReusableCBF.asInstanceOf[GenericCanBuildFrom[A]]
}