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Diffstat (limited to 'src/library/scalax/collection/generic/mutable/VectorView.scala')
-rw-r--r-- | src/library/scalax/collection/generic/mutable/VectorView.scala | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/src/library/scalax/collection/generic/mutable/VectorView.scala b/src/library/scalax/collection/generic/mutable/VectorView.scala new file mode 100644 index 0000000000..05a7bf6f5a --- /dev/null +++ b/src/library/scalax/collection/generic/mutable/VectorView.scala @@ -0,0 +1,95 @@ +/* __ *\ +** ________ ___ / / ___ Scala API ** +** / __/ __// _ | / / / _ | (c) 2003-2008, LAMP/EPFL ** +** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ ** +** /____/\___/_/ |_/____/_/ | | ** +** |/ ** +\* */ + +// $Id: Sequence.scala 16092 2008-09-12 10:37:06Z nielsen $ + + +package scalax.collection.generic.mutable + +import collection.mutable.Vector +import collection.mutable.Vector._ + +/** A non-strict projection of an iterable. + * @author Sean McDirmid + * @author Martin Odersky + * @note this should really be a virtual class of SequenceFactory + */ +trait VectorView[+UC[B] <: Vector[B], A] extends SequenceView[UC, A] with Vector[A] { +self => + + /** refined from Iterable.View */ + val origin: Vector[_] + + trait Transformed[B] extends super.Transformed[B] with VectorView[UC, B] { + override val origin = self + override def elements: Iterator[B] = new Elements(0, length) + override protected def asCC = asInstanceOf[VectorView[UC, B]] + } + + class Appended(that: Vector[A]) extends super.Appended[A](that) with Transformed[A] { + override def update(idx: Int, elem: A) { + val ll = self.length + if (idx < ll) self.update(idx, elem) else that.update(idx - ll, elem) + } + } + + class Sliced(from: Int, to: Int) extends super.Sliced(from, to) with Transformed[A] { + override def update(idx: Int, elem: A) { + if (idx >= 0 && idx < length) self.update(idx + from, elem) + else throw new IndexOutOfBoundsException(idx.toString) + } + override def slice(from1: Int, to1: Int) = + new self.Sliced(from + (from1 min length max 0) , to + (to1 min length max 0)) + } + + class Reversed extends super.Reversed with Transformed[A] { + override def update(idx: Int, elem: A) { + self.update(length - 1 - idx, elem) + } + } + + class Zipped[B](that: Vector[B]) extends super.Zipped[B](that) with Transformed[(A, B)] { + override def update(idx: Int, elem: (A, B)) { + self.update(idx, elem._1) + that.update(idx, elem._2) + } + } + + def ++(that: Vector[A]): VectorView[UC, A] = + new Appended(that).asCC + + override def reverse: VectorView[UC, A] = + (new Reversed).asCC + + private def toVector[B](xs: Iterable[B]): Vector[B] = xs match { + case ras: Vector[_] => ras.asInstanceOf[Vector[B]] + case _ => Vector() ++ xs + } + + override def zip[B](that: Iterable[B]): VectorView[UC, (A, B)] = + new Zipped(toVector(that)).asCC + + override def zipWithIndex: VectorView[UC, (A, Int)] = + zip((0 until length).asInstanceOf[Null]) // !!! + override def take(n: Int): VectorView[UC, A] = + slice(0, n) + override def drop(n: Int): VectorView[UC, A] = + slice(n, Math.MAX_INT) + override def splitAt(n: Int): (VectorView[UC, A], VectorView[UC, A]) = (take(n), drop(n)) + override def slice(from: Int, until: Int): VectorView[UC, A] = + new Sliced(from, until).asCC + override def takeWhile(p: A => Boolean): VectorView[UC, A] = + take(prefixLength(p)) + override def dropWhile(p: A => Boolean): VectorView[UC, A] = + drop(prefixLength(p)) + override def span(p: A => Boolean): (VectorView[UC, A], VectorView[UC, A]) = { + val n = prefixLength(p) + (take(n), drop(n)) + } +} + |