diff options
Diffstat (limited to 'src/library/scala/collection/TraversableViewLike.scala')
-rw-r--r-- | src/library/scala/collection/TraversableViewLike.scala | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/src/library/scala/collection/TraversableViewLike.scala b/src/library/scala/collection/TraversableViewLike.scala index 5926c69ebf..0901d749c3 100644 --- a/src/library/scala/collection/TraversableViewLike.scala +++ b/src/library/scala/collection/TraversableViewLike.scala @@ -189,6 +189,15 @@ trait TraversableViewLike[+A, } final override protected[this] def viewIdentifier = "A" } + + trait Prepended[B >: A] extends Transformed[B] { + protected[this] val fst: GenTraversable[B] + def foreach[U](f: B => U) { + fst foreach f + self foreach f + } + final override protected[this] def viewIdentifier = "A" + } trait Filtered extends Transformed[A] { protected[this] val pred: A => Boolean @@ -222,11 +231,15 @@ trait TraversableViewLike[+A, final override protected[this] def viewIdentifier = "D" } - override def ++[B >: A, That](xs: GenTraversableOnce[B])(implicit bf: CanBuildFrom[This, B, That]): That = { + override def ++[B >: A, That](xs: GenTraversableOnce[B])(implicit bf: CanBuildFrom[This, B, That]): That = newAppended(xs.seq.toTraversable).asInstanceOf[That] -// was: if (bf.isInstanceOf[ByPassCanBuildFrom]) newAppended(that).asInstanceOf[That] -// else super.++[B, That](that)(bf) - } + + override def ++:[B >: A, That](xs: TraversableOnce[B])(implicit bf: CanBuildFrom[This, B, That]): That = + newPrepended(xs.seq.toTraversable).asInstanceOf[That] + + // Need second one because of optimization in TraversableLike + override def ++:[B >: A, That](xs: Traversable[B])(implicit bf: CanBuildFrom[This, B, That]): That = + newPrepended(xs).asInstanceOf[That] override def map[B, That](f: A => B)(implicit bf: CanBuildFrom[This, B, That]): That = { newMapped(f).asInstanceOf[That] @@ -253,6 +266,7 @@ trait TraversableViewLike[+A, */ protected def newForced[B](xs: => GenSeq[B]): Transformed[B] = new { val forced = xs } with AbstractTransformed[B] with Forced[B] protected def newAppended[B >: A](that: GenTraversable[B]): Transformed[B] = new { val rest = that } with AbstractTransformed[B] with Appended[B] + protected def newPrepended[B >: A](that: GenTraversable[B]): Transformed[B] = new { val fst = that } with AbstractTransformed[B] with Prepended[B] protected def newMapped[B](f: A => B): Transformed[B] = new { val mapping = f } with AbstractTransformed[B] with Mapped[B] protected def newFlatMapped[B](f: A => GenTraversableOnce[B]): Transformed[B] = new { val mapping = f } with AbstractTransformed[B] with FlatMapped[B] protected def newFiltered(p: A => Boolean): Transformed[A] = new { val pred = p } with AbstractTransformed[A] with Filtered |