diff options
Diffstat (limited to 'src/library/scala/collection/TraversableLike.scala')
| -rw-r--r-- | src/library/scala/collection/TraversableLike.scala | 44 |
1 files changed, 25 insertions, 19 deletions
diff --git a/src/library/scala/collection/TraversableLike.scala b/src/library/scala/collection/TraversableLike.scala index 8b430ca3d2..32d31f0be8 100644 --- a/src/library/scala/collection/TraversableLike.scala +++ b/src/library/scala/collection/TraversableLike.scala @@ -6,7 +6,8 @@ ** |/ ** \* */ -package scala.collection +package scala +package collection import generic._ import mutable.{ Builder } @@ -86,7 +87,7 @@ trait TraversableLike[+A, +Repr] extends Any def repr: Repr = this.asInstanceOf[Repr] final def isTraversableAgain: Boolean = true - + /** The underlying collection seen as an instance of `$Coll`. * By default this is implemented as the current collection object itself, * but this can be overridden. @@ -174,7 +175,7 @@ trait TraversableLike[+A, +Repr] extends Any * * @usecase def ++:[B](that: TraversableOnce[B]): $Coll[B] * @inheritdoc - * + * * Example: * {{{ * scala> val x = List(1) @@ -252,18 +253,21 @@ trait TraversableLike[+A, +Repr] extends Any b.result } + private def filterImpl(p: A => Boolean, isFlipped: Boolean): Repr = { + val b = newBuilder + for (x <- this) + if (p(x) != isFlipped) b += x + + b.result + } + /** Selects all elements of this $coll which satisfy a predicate. * * @param p the predicate used to test elements. * @return a new $coll consisting of all elements of this $coll that satisfy the given * predicate `p`. The order of the elements is preserved. */ - def filter(p: A => Boolean): Repr = { - val b = newBuilder - for (x <- this) - if (p(x)) b += x - b.result - } + def filter(p: A => Boolean): Repr = filterImpl(p, isFlipped = false) /** Selects all elements of this $coll which do not satisfy a predicate. * @@ -271,11 +275,11 @@ trait TraversableLike[+A, +Repr] extends Any * @return a new $coll consisting of all elements of this $coll that do not satisfy the given * predicate `p`. The order of the elements is preserved. */ - def filterNot(p: A => Boolean): Repr = filter(!p(_)) + def filterNot(p: A => Boolean): Repr = filterImpl(p, isFlipped = true) def collect[B, That](pf: PartialFunction[A, B])(implicit bf: CanBuildFrom[Repr, B, That]): That = { val b = bf(repr) - for (x <- this) if (pf.isDefinedAt(x)) b += pf(x) + foreach(pf.runWith(b += _)) b.result } @@ -341,8 +345,8 @@ trait TraversableLike[+A, +Repr] extends Any * $mayNotTerminateInf * * @param p the predicate used to test elements. - * @return `true` if the given predicate `p` holds for all elements - * of this $coll, otherwise `false`. + * @return `true` if this $coll is empty, otherwise `true` if the given predicate `p` + * holds for all elements of this $coll, otherwise `false`. */ def forall(p: A => Boolean): Boolean = { var result = true @@ -358,8 +362,8 @@ trait TraversableLike[+A, +Repr] extends Any * $mayNotTerminateInf * * @param p the predicate used to test elements. - * @return `true` if the given predicate `p` holds for some of the - * elements of this $coll, otherwise `false`. + * @return `false` if this $coll is empty, otherwise `true` if the given predicate `p` + * holds for some of the elements of this $coll, otherwise `false` */ def exists(p: A => Boolean): Boolean = { var result = false @@ -415,7 +419,7 @@ trait TraversableLike[+A, +Repr] extends Any /** Selects the first element of this $coll. * $orderDependent * @return the first element of this $coll. - * @throws `NoSuchElementException` if the $coll is empty. + * @throws NoSuchElementException if the $coll is empty. */ def head: A = { var result: () => A = () => throw new NoSuchElementException @@ -469,7 +473,7 @@ trait TraversableLike[+A, +Repr] extends Any * $orderDependent * @return a $coll consisting of all elements of this $coll * except the last one. - * @throws `UnsupportedOperationException` if the $coll is empty. + * @throws UnsupportedOperationException if the $coll is empty. */ def init: Repr = { if (isEmpty) throw new UnsupportedOperationException("empty.init") @@ -477,7 +481,7 @@ trait TraversableLike[+A, +Repr] extends Any var follow = false val b = newBuilder b.sizeHint(this, -1) - for (x <- this.seq) { + for (x <- this) { if (follow) b += lst else follow = true lst = x @@ -502,7 +506,7 @@ trait TraversableLike[+A, +Repr] extends Any private[this] def sliceInternal(from: Int, until: Int, b: Builder[A, Repr]): Repr = { var i = 0 breakable { - for (x <- this.seq) { + for (x <- this) { if (i >= from) b += x i += 1 if (i >= until) break @@ -619,7 +623,9 @@ trait TraversableLike[+A, +Repr] extends Any } } + @deprecatedOverriding("Enforce contract of toTraversable that if it is Traversable it returns itself.", "2.11.0") def toTraversable: Traversable[A] = thisCollection + def toIterator: Iterator[A] = toStream.iterator def toStream: Stream[A] = toBuffer.toStream // Override to provide size hint. |