diff options
Diffstat (limited to 'src/library')
6 files changed, 79 insertions, 34 deletions
diff --git a/src/library/scala/collection/IndexedSeq.scala b/src/library/scala/collection/IndexedSeq.scala index e30d2f07bb..63e5adf428 100644 --- a/src/library/scala/collection/IndexedSeq.scala +++ b/src/library/scala/collection/IndexedSeq.scala @@ -28,8 +28,14 @@ trait IndexedSeq[+A] extends Seq[A] * @define coll indexed sequence * @define Coll `IndexedSeq` */ -object IndexedSeq extends SeqFactory[IndexedSeq] { - implicit def canBuildFrom[A]: CanBuildFrom[Coll, A, IndexedSeq[A]] = ReusableCBF.asInstanceOf[GenericCanBuildFrom[A]] +object IndexedSeq extends IndexedSeqFactory[IndexedSeq] { + // A single CBF which can be checked against to identify + // an indexed collection type. + override val ReusableCBF: GenericCanBuildFrom[Nothing] = new GenericCanBuildFrom[Nothing] { + override def apply() = newBuilder[Nothing] + } def newBuilder[A]: Builder[A, IndexedSeq[A]] = immutable.IndexedSeq.newBuilder[A] + implicit def canBuildFrom[A]: CanBuildFrom[Coll, A, IndexedSeq[A]] = + ReusableCBF.asInstanceOf[GenericCanBuildFrom[A]] } diff --git a/src/library/scala/collection/generic/GenTraversableFactory.scala b/src/library/scala/collection/generic/GenTraversableFactory.scala index d5edf5961e..a43862abaf 100644 --- a/src/library/scala/collection/generic/GenTraversableFactory.scala +++ b/src/library/scala/collection/generic/GenTraversableFactory.scala @@ -36,15 +36,12 @@ import scala.language.higherKinds * @see GenericCanBuildFrom */ abstract class GenTraversableFactory[CC[X] <: GenTraversable[X] with GenericTraversableTemplate[X, CC]] - extends GenericCompanion[CC] { +extends GenericCompanion[CC] { - // A default implementation of GenericCanBuildFrom which can be cast - // to whatever is desired. - private class ReusableCBF extends GenericCanBuildFrom[Nothing] { + private[this] val ReusableCBFInstance: GenericCanBuildFrom[Nothing] = new GenericCanBuildFrom[Nothing] { override def apply() = newBuilder[Nothing] } - // Working around SI-4789 by using a lazy val instead of an object. - lazy val ReusableCBF: GenericCanBuildFrom[Nothing] = new ReusableCBF + def ReusableCBF: GenericCanBuildFrom[Nothing] = ReusableCBFInstance /** A generic implementation of the `CanBuildFrom` trait, which forwards * all calls to `apply(from)` to the `genericBuilder` method of diff --git a/src/library/scala/collection/generic/IndexedSeqFactory.scala b/src/library/scala/collection/generic/IndexedSeqFactory.scala new file mode 100644 index 0000000000..200d033c2d --- /dev/null +++ b/src/library/scala/collection/generic/IndexedSeqFactory.scala @@ -0,0 +1,21 @@ +/* __ *\ +** ________ ___ / / ___ Scala API ** +** / __/ __// _ | / / / _ | (c) 2003-2011, LAMP/EPFL ** +** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ ** +** /____/\___/_/ |_/____/_/ | | ** +** |/ ** +\* */ + +package scala.collection +package generic + +import language.higherKinds + +/** A template for companion objects of IndexedSeq and subclasses thereof. + * + * @since 2.10 + */ +abstract class IndexedSeqFactory[CC[X] <: IndexedSeq[X] with GenericTraversableTemplate[X, CC]] extends SeqFactory[CC] { + override def ReusableCBF: GenericCanBuildFrom[Nothing] = + scala.collection.IndexedSeq.ReusableCBF.asInstanceOf[GenericCanBuildFrom[Nothing]] +} diff --git a/src/library/scala/collection/immutable/IndexedSeq.scala b/src/library/scala/collection/immutable/IndexedSeq.scala index e98df46c9b..bf4ba3a381 100644 --- a/src/library/scala/collection/immutable/IndexedSeq.scala +++ b/src/library/scala/collection/immutable/IndexedSeq.scala @@ -31,11 +31,12 @@ trait IndexedSeq[+A] extends Seq[A] * @define coll indexed sequence * @define Coll `IndexedSeq` */ -object IndexedSeq extends SeqFactory[IndexedSeq] { +object IndexedSeq extends IndexedSeqFactory[IndexedSeq] { class Impl[A](buf: ArrayBuffer[A]) extends AbstractSeq[A] with IndexedSeq[A] with Serializable { def length = buf.length def apply(idx: Int) = buf.apply(idx) } - implicit def canBuildFrom[A]: CanBuildFrom[Coll, A, IndexedSeq[A]] = ReusableCBF.asInstanceOf[GenericCanBuildFrom[A]] def newBuilder[A]: Builder[A, IndexedSeq[A]] = Vector.newBuilder[A] + implicit def canBuildFrom[A]: CanBuildFrom[Coll, A, IndexedSeq[A]] = + ReusableCBF.asInstanceOf[GenericCanBuildFrom[A]] } diff --git a/src/library/scala/collection/immutable/Vector.scala b/src/library/scala/collection/immutable/Vector.scala index dff221ad05..f083e80175 100644 --- a/src/library/scala/collection/immutable/Vector.scala +++ b/src/library/scala/collection/immutable/Vector.scala @@ -18,16 +18,10 @@ import scala.collection.parallel.immutable.ParVector /** Companion object to the Vector class */ -object Vector extends SeqFactory[Vector] { - private[collection] class VectorReusableCBF extends GenericCanBuildFrom[Nothing] { - override def apply() = newBuilder[Nothing] - } - - private val VectorReusableCBF: GenericCanBuildFrom[Nothing] = new VectorReusableCBF - - implicit def canBuildFrom[A]: CanBuildFrom[Coll, A, Vector[A]] = - VectorReusableCBF.asInstanceOf[CanBuildFrom[Coll, A, Vector[A]]] +object Vector extends IndexedSeqFactory[Vector] { def newBuilder[A]: Builder[A, Vector[A]] = new VectorBuilder[A] + implicit def canBuildFrom[A]: CanBuildFrom[Coll, A, Vector[A]] = + ReusableCBF.asInstanceOf[GenericCanBuildFrom[A]] private[immutable] val NIL = new Vector[Nothing](0, 0, 0) override def empty[A]: Vector[A] = NIL } @@ -137,20 +131,17 @@ override def companion: GenericCompanion[Vector] = Vector // SeqLike api - override def updated[B >: A, That](index: Int, elem: B)(implicit bf: CanBuildFrom[Vector[A], B, That]): That = bf match { - case _: Vector.VectorReusableCBF => updateAt(index, elem).asInstanceOf[That] // just ignore bf - case _ => super.updated(index, elem)(bf) - } + override def updated[B >: A, That](index: Int, elem: B)(implicit bf: CanBuildFrom[Vector[A], B, That]): That = + if (bf eq IndexedSeq.ReusableCBF) updateAt(index, elem).asInstanceOf[That] // just ignore bf + else super.updated(index, elem)(bf) - override def +:[B >: A, That](elem: B)(implicit bf: CanBuildFrom[Vector[A], B, That]): That = bf match { - case _: Vector.VectorReusableCBF => appendFront(elem).asInstanceOf[That] // just ignore bf - case _ => super.+:(elem)(bf) - } + override def +:[B >: A, That](elem: B)(implicit bf: CanBuildFrom[Vector[A], B, That]): That = + if (bf eq IndexedSeq.ReusableCBF) appendFront(elem).asInstanceOf[That] // just ignore bf + else super.+:(elem)(bf) - override def :+[B >: A, That](elem: B)(implicit bf: CanBuildFrom[Vector[A], B, That]): That = bf match { - case _: Vector.VectorReusableCBF => appendBack(elem).asInstanceOf[That] // just ignore bf - case _ => super.:+(elem)(bf) - } + override def :+[B >: A, That](elem: B)(implicit bf: CanBuildFrom[Vector[A], B, That]): That = + if (bf eq IndexedSeq.ReusableCBF) appendBack(elem).asInstanceOf[That] // just ignore bf + else super.:+(elem)(bf) override def take(n: Int): Vector[A] = { if (n <= 0) diff --git a/src/library/scala/collection/mutable/MultiMap.scala b/src/library/scala/collection/mutable/MultiMap.scala index 31c8a50a84..4635bfbe64 100644 --- a/src/library/scala/collection/mutable/MultiMap.scala +++ b/src/library/scala/collection/mutable/MultiMap.scala @@ -15,8 +15,36 @@ package mutable /** A trait for mutable maps with multiple values assigned to a key. * * This class is typically used as a mixin. It turns maps which map `A` - * to `Set[B]` objects into multi maps which map `A` to - * `B` objects. + * to `Set[B]` objects into multimaps that map `A` to `B` objects. + * + * @example {{{ + * // first import all necessary types from package `collection.mutable` + * import collection.mutable.{ HashMap, MultiMap, Set } + * + * // to create a `MultiMap` the easiest way is to mixin it into a normal + * // `Map` instance + * val mm = new HashMap[Int, Set[String]] with MultiMap[Int, String] + * + * // to add key-value pairs to a multimap it is important to use + * // the method `addBinding` because standard methods like `+` will + * // overwrite the complete key-value pair instead of adding the + * // value to the existing key + * mm.addBinding(1, "a") + * mm.addBinding(2, "b") + * mm.addBinding(1, "c") + * + * // mm now contains `Map(2 -> Set(b), 1 -> Set(c, a))` + * + * // to check if the multimap contains a value there is method + * // `entryExists`, which allows to traverse the including set + * mm.entryExists(1, _ == "a") == true + * mm.entryExists(1, _ == "b") == false + * mm.entryExists(2, _ == "b") == true + * + * // to remove a previous added value there is the method `removeBinding` + * mm.removeBinding(1, "a") + * mm.entryExists(1, _ == "a") == false + * }}} * * @define coll multimap * @define Coll `MultiMap` @@ -57,7 +85,8 @@ trait MultiMap[A, B] extends Map[A, Set[B]] { this } - /** Removes the binding of `value` to `key` if it exists. + /** Removes the binding of `value` to `key` if it exists, otherwise this + * operation doesn't have any effect. * * If this was the last value assigned to the specified key, the * set assigned to that key will be removed as well. |