Packages

  • package root

    This is the documentation for the Scala standard library.

    This is the documentation for the Scala standard library.

    Package structure

    The scala package contains core types like Int, Float, Array or Option which are accessible in all Scala compilation units without explicit qualification or imports.

    Notable packages include:

    Other packages exist. See the complete list on the right.

    Additional parts of the standard library are shipped as separate libraries. These include:

    • scala.reflect - Scala's reflection API (scala-reflect.jar)
    • scala.xml - XML parsing, manipulation, and serialization (scala-xml.jar)
    • scala.swing - A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar)
    • scala.util.parsing - Parser combinators (scala-parser-combinators.jar)

    Automatic imports

    Identifiers in the scala package and the scala.Predef object are always in scope by default.

    Some of these identifiers are type aliases provided as shortcuts to commonly used classes. For example, List is an alias for scala.collection.immutable.List.

    Other aliases refer to classes provided by the underlying platform. For example, on the JVM, String is an alias for java.lang.String.

    Definition Classes
    root
  • package scala

    Core Scala types.

    Core Scala types. They are always available without an explicit import.

    Definition Classes
    root
  • package collection

    Contains the base traits and objects needed to use and extend Scala's collection library.

    Contains the base traits and objects needed to use and extend Scala's collection library.

    Guide

    A detailed guide for using the collections library is available at http://docs.scala-lang.org/overviews/collections/introduction.html. Developers looking to extend the collections library can find a description of its architecture at http://docs.scala-lang.org/overviews/core/architecture-of-scala-collections.html.

    Using Collections

    It is convenient to treat all collections as either a scala.collection.Traversable or scala.collection.Iterable, as these traits define the vast majority of operations on a collection.

    Collections can, of course, be treated as specifically as needed, and the library is designed to ensure that the methods that transform collections will return a collection of the same type:

    scala> val array = Array(1,2,3,4,5,6)
    array: Array[Int] = Array(1, 2, 3, 4, 5, 6)
    
    scala> array map { _.toString }
    res0: Array[String] = Array(1, 2, 3, 4, 5, 6)
    
    scala> val list = List(1,2,3,4,5,6)
    list: List[Int] = List(1, 2, 3, 4, 5, 6)
    
    scala> list map { _.toString }
    res1: List[String] = List(1, 2, 3, 4, 5, 6)

    Creating Collections

    The most common way to create a collection is to use its companion object as a factory. The three most commonly used collections are scala.collection.Seq, scala.collection.immutable.Set, and scala.collection.immutable.Map. They can be used directly as shown below since their companion objects are all available as type aliases in either the scala package or in scala.Predef. New collections are created like this:

    scala> val seq = Seq(1,2,3,4,1)
    seq: Seq[Int] = List(1, 2, 3, 4, 1)
    
    scala> val set = Set(1,2,3,4,1)
    set: scala.collection.immutable.Set[Int] = Set(1, 2, 3, 4)
    
    scala> val map = Map(1 -> "one", 2 -> "two", 3 -> "three", 2 -> "too")
    map: scala.collection.immutable.Map[Int,String] = Map(1 -> one, 2 -> too, 3 -> three)

    It is also typical to prefer the scala.collection.immutable collections over those in scala.collection.mutable; the types aliased in the scala.Predef object are the immutable versions.

    Also note that the collections library was carefully designed to include several implementations of each of the three basic collection types. These implementations have specific performance characteristics which are described in the guide.

    The concrete parallel collections also have specific performance characteristics which are described in the parallel collections guide

    Converting to and from Java Collections

    The scala.collection.JavaConverters object provides a collection of decorators that allow converting between Scala and Java collections using asScala and asJava methods.

    Definition Classes
    scala
  • package parallel

    Package object for parallel collections.

    Package object for parallel collections.

    Definition Classes
    collection
  • package mutable
    Definition Classes
    parallel
  • trait ResizableParArrayCombiner[T] extends LazyCombiner[T, ParArray[T], ExposedArrayBuffer[T]]

    An array combiner that uses a chain of arraybuffers to store elements.

    An array combiner that uses a chain of arraybuffers to store elements.

    Definition Classes
    mutable
  • CopyChainToArray

class CopyChainToArray extends Task[Unit, CopyChainToArray]

Ordering
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Inherited
  1. CopyChainToArray
  2. Task
  3. AnyRef
  4. Any
Implicitly
  1. by CollectionsHaveToParArray
  2. by any2stringadd
  3. by StringFormat
  4. by Ensuring
  5. by ArrowAssoc
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Visibility
  1. Public
  2. All

Instance Constructors

  1. new CopyChainToArray(array: Array[Any], offset: Int, howmany: Int)

Type Members

  1. type Result = Unit
    Definition Classes
    Task

Value Members

  1. def forwardThrowable(): Unit
    Definition Classes
    Task
  2. def leaf(prev: Option[Unit]): Unit

    Body of the task - non-divisible unit of work done by this task.

    Body of the task - non-divisible unit of work done by this task. Optionally is provided with the result from the previous completed task or None if there was no previous task (or the previous task is uncompleted or unknown).

    Definition Classes
    CopyChainToArrayTask
  3. def repr: CopyChainToArray
    Definition Classes
    Task
  4. var result: Unit

    A result that can be accessed once the task is completed.

    A result that can be accessed once the task is completed.

    Definition Classes
    CopyChainToArrayTask
  5. def shouldSplitFurther: Boolean

    Decides whether or not this task should be split further.

    Decides whether or not this task should be split further.

    Definition Classes
    CopyChainToArrayTask
  6. def split: immutable.List[CopyChainToArray]

    Splits this task into a list of smaller tasks.

    Splits this task into a list of smaller tasks.

    Definition Classes
    CopyChainToArrayTask
  7. val throwable: Throwable
    Definition Classes
    Task
    Annotations
    @volatile()
  8. def toParArray: ParArray[T]
    Implicit
    This member is added by an implicit conversion from CopyChainToArray to CollectionsHaveToParArray[CopyChainToArray, T] performed by method CollectionsHaveToParArray in scala.collection.parallel. This conversion will take place only if an implicit value of type (CopyChainToArray) ⇒ GenTraversableOnce[T] is in scope.
    Definition Classes
    CollectionsHaveToParArray