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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2009, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala.collection.generic
import Math.MAX_INT
import TraversableView.NoBuilder
/** A base class for views of Traversable.
* Every subclass has to implenment the foreach method
* @author Martin Odersky
* @version 2.8
*/
trait TraversableView[+A, +Coll <: Traversable[_]] extends TraversableViewTemplate[A, Coll, TraversableView[A, Coll]]
object TraversableView {
class NoBuilder[A] extends Builder[A, Nothing, TraversableView[_, _]] {
def +=(elem: A) {}
def elements: Iterator[A] = Iterator.empty
def result() = throw new UnsupportedOperationException("TraversableView.Builder.result")
def clear() {}
}
type Coll = TraversableView[_, _]
implicit def builderFactory[A]: BuilderFactory[A, TraversableView[A, Traversable[_]], Coll] = new BuilderFactory[A, TraversableView[A, Traversable[_]], Coll] { def apply(from: Coll) = new NoBuilder }
}
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