1 files changed, 70 insertions, 3 deletions
diff --git a/src/library/scala/collection/mutable/VectorView.scala b/src/library/scala/collection/mutable/VectorView.scala
index 1564511cab..45a21e3429 100644
--- a/src/library/scala/collection/mutable/VectorView.scala
+++ b/src/library/scala/collection/mutable/VectorView.scala
@@ -13,18 +13,85 @@ package scala.collection
 package mutable
 
 import generic._
+import Math.MAX_INT
 
 import TraversableView.NoBuilder
 
-/** A non-strict projection of an iterable.
+/** A non-strict view of a mutable vector.
+ *  This is a leaf class which mixes methods returning a plain vector view
+ *  and methods returning a mutable vector view.
+ *  There is no associated `Like' class.
  * @author Sean McDirmid
  * @author Martin Odersky
  * @version 2.8
  * @since   2.8
  */
-trait VectorView[A, +Coll] extends VectorViewLike[A, Coll, VectorView[A, Coll]]
+trait VectorView[A, +Coll] extends scala.collection.VectorView[A, Coll] {
+self =>
 
-object VectorView {
+  def update(idx: Int, elem: A)
+
+  trait Transformed[B] extends VectorView[B, Coll] with super.Transformed[B] {
+    def update(idx: Int, elem: B)
+  }
+
+  trait Sliced extends Transformed[A] with super.Sliced {
+    override def update(idx: Int, elem: A) =
+      if (idx + from < until) self.update(idx + from, elem)
+      else throw new IndexOutOfBoundsException(idx.toString)
+    override def slice(from1: Int, until1: Int): Transformed[A] =
+      newSliced(from1 max 0, until1 max 0)
+  }
+
+  trait Filtered extends Transformed[A] with super.Filtered {
+    override def update(idx: Int, elem: A) = self.update(index(idx), elem)
+  }
+
+  trait TakenWhile extends Transformed[A] with super.TakenWhile {
+    override def update(idx: Int, elem: A) =
+      if (idx < len) self.update(idx, elem)
+      else throw new IndexOutOfBoundsException(idx.toString)
+  }
+
+  trait DroppedWhile extends Transformed[A] with super.DroppedWhile {
+    override def update(idx: Int, elem: A) =
+      if (idx >= 0) self.update(idx + start, elem)
+      else throw new IndexOutOfBoundsException(idx.toString)
+  }
+
+  trait Reversed extends Transformed[A] with super.Reversed {
+    override def update(idx: Int, elem: A) = self.update(length - 1 - idx, elem)
+  }
+
+  /** Boilerplate method, to override in each subclass
+   *  This method could be eliminated if Scala had virtual classes
+   */
+  protected override def newFiltered(p: A => Boolean): Transformed[A] = new Filtered { val pred = p }
+  protected override def newSliced(_from: Int, _until: Int): Transformed[A] = new Sliced { val from = _from; val until = _until }
+  protected override def newDroppedWhile(p: A => Boolean): Transformed[A] = new DroppedWhile { val pred = p }
+  protected override def newTakenWhile(p: A => Boolean): Transformed[A] = new TakenWhile { val pred = p }
+  protected override def newReversed: Transformed[A] = new Reversed { }
+
+  // Todo: if we replace VectorView[A, Coll] below by
+  // private[this] type This = VectorView[A, Coll]
+  // The interpreter will display resX.This.
+  // It shouldn't.
+
+  override def filter(p: A => Boolean): VectorView[A, Coll] = newFiltered(p)
+  override def init: VectorView[A, Coll]  = newSliced(0, size - 1).asInstanceOf[VectorView[A, Coll]]
+  override def drop(n: Int): VectorView[A, Coll] = newSliced(n max 0, MAX_INT).asInstanceOf[VectorView[A, Coll]]
+  override def take(n: Int): VectorView[A, Coll] = newSliced(0, n).asInstanceOf[VectorView[A, Coll]]
+  override def slice(from: Int, until: Int): VectorView[A, Coll] = newSliced(from max 0, until).asInstanceOf[VectorView[A, Coll]]
+  override def dropWhile(p: A => Boolean): VectorView[A, Coll] = newDroppedWhile(p).asInstanceOf[VectorView[A, Coll]]
+  override def takeWhile(p: A => Boolean): VectorView[A, Coll] = newTakenWhile(p).asInstanceOf[VectorView[A, Coll]]
+  override def span(p: A => Boolean): (VectorView[A, Coll], VectorView[A, Coll]) = (takeWhile(p), dropWhile(p))
+  override def splitAt(n: Int): (VectorView[A, Coll], VectorView[A, Coll]) = (take(n), drop(n))
+  override def reverse: VectorView[A, Coll] = newReversed.asInstanceOf[VectorView[A, Coll]]
+}
+
+/*
+ * object VectorView {
   type Coll = TraversableView[_, C] forSome { type C <: scala.collection.Traversable[_] }
   implicit def builderFactory[A]: BuilderFactory[A, VectorView[A, Vector[_]], Coll] = new BuilderFactory[A, VectorView[A, mutable.Vector[_]], Coll] { def apply(from: Coll) = new NoBuilder }
 }
+*/