path: root/src/library/scala/collection/generic/TraversableForwarder.scala

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2010, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

// $Id$


package scala.collection.generic
import scala.collection._

import mutable.{Buffer, StringBuilder}
import immutable.{List, Stream}
// import immutable.{List, Nil, ::, Stream}

/** <p>
 *    This trait implements a forwarder for traversable objects. It forwards
 *    all calls to a different iterable object, except for
 *  </p>
 *  <ul>
 *    <li><code>toString</code>, <code>hashCode</code>, <code>equals</code>,
 *      <code>stringPrefix</code>
 *    </li>
 *    <li><code>newBuilder</code>, <code>view</code></li>
 *    <li>all calls creating a new iterable object of the same kind</li>
 *  </ul>
 *  <p>
 *    The above methods are forwarded by subclass
 *    <a href="TraversableProxy.html" target="ContentFrame">
 *    <code>TraversableProxy</code></a>.
 *  </p>
 *
 *  @author  Martin Odersky
 *  @version 2.8
 *  @since   2.8
 */
trait TraversableForwarder[+A] extends Traversable[A] {

  /** The iterable object to which calls are forwarded */
  protected def underlying: Traversable[A]

  // Iterable delegates
  // Iterable methods could be printed by  cat TarversableLike.scala | sed -n '/trait Iterable/,$ p' | egrep '^  (override )?def'

  override def isEmpty = underlying.isEmpty
  override def nonEmpty = underlying.nonEmpty
  override def hasDefiniteSize = underlying.hasDefiniteSize
  override def foreach[B](f: A => B) = underlying.foreach(f)
  override def forall(p: A => Boolean): Boolean = underlying.forall(p)
  override def exists(p: A => Boolean): Boolean = underlying.exists(p)
  override def count(p: A => Boolean): Int = underlying.count(p)
  override def find(p: A => Boolean): Option[A] = underlying.find(p)
  override def foldLeft[B](z: B)(op: (B, A) => B): B = underlying.foldLeft(z)(op)
  override def foldRight[B](z: B)(op: (A, B) => B): B = underlying.foldRight(z)(op)
  override def reduceLeft[B >: A](op: (B, A) => B): B = underlying.reduceLeft(op)
  override def reduceRight[B >: A](op: (A, B) => B): B = underlying.reduceRight(op)
  override def reduceLeftOption[B >: A](op: (B, A) => B): Option[B] = underlying.reduceLeftOption(op)
  override def reduceRightOption[B >: A](op: (A, B) => B): Option[B] = underlying.reduceRightOption(op)
  override def copyToBuffer[B >: A](dest: Buffer[B]) = underlying.copyToBuffer(dest)
  override def copyToArray[B >: A](xs: Array[B], start: Int, len: Int) = underlying.copyToArray(xs, start, len)
  override def toArray[B >: A : ClassManifest]: Array[B] = underlying.toArray
  override def toList: List[A] = underlying.toList
  override def toSeq: Seq[A] = underlying.toSeq
  override def toStream: Stream[A] = underlying.toStream
  override def mkString(start: String, sep: String, end: String): String = underlying.mkString(start, sep, end)
  override def addString(b: StringBuilder, start: String, sep: String, end: String): StringBuilder = underlying.addString(b, start, sep, end)

  override def head: A = underlying.head
  override def last: A = underlying.last
  override def lastOption: Option[A] = underlying.lastOption
}