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Class scala.collection.parallel.mutable.ParArray

Companion object ParArray

class ParArray[T] extends ParSeq[T] with GenericParTemplate[T, ParArray] with ParSeqLike[T, ParArray[T], ArraySeq[T]] with Serializable

Parallel sequence holding elements in a linear array.

ParArray is a parallel sequence with a predefined size. The size of the array cannot be changed after it's been created.

ParArray internally keeps an array containing the elements. This means that bulk operations based on traversal ensure fast access to elements. ParArray uses lazy builders that create the internal data array only after the size of the array is known. In the meantime, they keep the result set fragmented. The fragments are copied into the resulting data array in parallel using fast array copy operations once all the combiners are populated in parallel.

T

type of the elements in the array

Self Type
ParArray[T]
Annotations
@SerialVersionUID()
Source
ParArray.scala
Since

2.9

See also

Scala's Parallel Collections Library overview section on ParArray for more information.

Linear Supertypes

Instance Constructors

new ParArray(sz: Int)

Type Members

class Aggregate[S] extends Accessor[S, Aggregate[S]]

Attributes
protected[this]
Definition Classes
ParIterableLike

trait BuilderOps[Elem, To] extends AnyRef

Definition Classes
ParIterableLike

class Collect[S, That] extends Transformer[Combiner[S, That], Collect[S, That]]

Attributes
protected[this]
Definition Classes
ParIterableLike

abstract class Composite[FR, SR, R, First <: StrictSplitterCheckTask[FR, _], Second <: StrictSplitterCheckTask[SR, _]] extends NonDivisibleTask[R, Composite[FR, SR, R, First, Second]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Copy[U >: T, That] extends Transformer[Combiner[U, That], Copy[U, That]]

Attributes
protected
Definition Classes
ParIterableLike

class CopyToArray[U >: T, This >: Repr] extends Accessor[Unit, CopyToArray[U, This]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Count extends Accessor[Int, Count]

Attributes
protected[this]
Definition Classes
ParIterableLike

class CreateScanTree[U >: T] extends Transformer[ScanTree[U], CreateScanTree[U]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Drop[U >: T, This >: Repr] extends Transformer[Combiner[U, This], Drop[U, This]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Exists extends Accessor[Boolean, Exists]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Filter[U >: T, This >: Repr] extends Transformer[Combiner[U, This], Filter[U, This]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class FilterNot[U >: T, This >: Repr] extends Transformer[Combiner[U, This], FilterNot[U, This]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Find[U >: T] extends Accessor[Option[U], Find[U]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class FlatMap[S, That] extends Transformer[Combiner[S, That], FlatMap[S, That]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Fold[U >: T] extends Accessor[U, Fold[U]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Forall extends Accessor[Boolean, Forall]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Foreach[S] extends Accessor[Unit, Foreach[S]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class FromScanTree[U >: T, That] extends StrictSplitterCheckTask[Combiner[U, That], FromScanTree[U, That]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class GroupBy[K, U >: T] extends Transformer[HashMapCombiner[K, U], GroupBy[K, U]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Max[U >: T] extends Accessor[Option[U], Max[U]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Min[U >: T] extends Accessor[Option[U], Min[U]]

Attributes
protected[this]
Definition Classes
ParIterableLike

trait NonDivisible[R] extends NonDivisibleTask[R, NonDivisible[R]]

Attributes
protected[this]
Definition Classes
ParIterableLike

trait NonDivisibleTask[R, Tp] extends StrictSplitterCheckTask[R, Tp]

Attributes
protected[this]
Definition Classes
ParIterableLike

abstract class ParComposite[FR, SR, R, First <: StrictSplitterCheckTask[FR, _], Second <: StrictSplitterCheckTask[SR, _]] extends Composite[FR, SR, R, First, Second]

Performs two tasks in parallel, and waits for both to finish.

Attributes
protected[this]
Definition Classes
ParIterableLike

class Partition[U >: T, This >: Repr] extends Transformer[(Combiner[U, This], Combiner[U, This]), Partition[U, This]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Product[U >: T] extends Accessor[U, Product[U]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Reduce[U >: T] extends Accessor[Option[U], Reduce[U]]

Attributes
protected[this]
Definition Classes
ParIterableLike

abstract class ResultMapping[R, Tp, R1] extends NonDivisibleTask[R1, ResultMapping[R, Tp, R1]]

Attributes
protected[this]
Definition Classes
ParIterableLike

case class ScanLeaf[U >: T](pit: IterableSplitter[U], op: (U, U) ⇒ U, from: Int, len: Int, prev: Option[ScanLeaf[U]], acc: U) extends ScanTree[U] with scala.Product with Serializable

Attributes
protected[this]
Definition Classes
ParIterableLike

case class ScanNode[U >: T](left: ScanTree[U], right: ScanTree[U]) extends ScanTree[U] with scala.Product with Serializable

Attributes
protected[this]
Definition Classes
ParIterableLike

trait ScanTree[U >: T] extends AnyRef

Attributes
protected[this]
Definition Classes
ParIterableLike

abstract class SeqComposite[FR, SR, R, First <: StrictSplitterCheckTask[FR, _], Second <: StrictSplitterCheckTask[SR, _]] extends Composite[FR, SR, R, First, Second]

Sequentially performs one task after another.

Attributes
protected[this]
Definition Classes
ParIterableLike

trait SignallingOps[PI <: DelegatedSignalling] extends AnyRef

Definition Classes
ParIterableLike

class Slice[U >: T, This >: Repr] extends Transformer[Combiner[U, This], Slice[U, This]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Span[U >: T, This >: Repr] extends Transformer[(Combiner[U, This], Combiner[U, This]), Span[U, This]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class SplitAt[U >: T, This >: Repr] extends Transformer[(Combiner[U, This], Combiner[U, This]), SplitAt[U, This]]

Attributes
protected[this]
Definition Classes
ParIterableLike

trait StrictSplitterCheckTask[R, Tp] extends Task[R, Tp]

Attributes
protected
Definition Classes
ParIterableLike

class Sum[U >: T] extends Accessor[U, Sum[U]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class Take[U >: T, This >: Repr] extends Transformer[Combiner[U, This], Take[U, This]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class TakeWhile[U >: T, This >: Repr] extends Transformer[(Combiner[U, This], Boolean), TakeWhile[U, This]]

Attributes
protected[this]
Definition Classes
ParIterableLike

trait TaskOps[R, Tp] extends AnyRef

Definition Classes
ParIterableLike

class ToParCollection[U >: T, That] extends Transformer[Combiner[U, That], ToParCollection[U, That]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class ToParMap[K, V, That] extends Transformer[Combiner[(K, V), That], ToParMap[K, V, That]]

Attributes
protected[this]
Definition Classes
ParIterableLike

class ZipAll[U >: T, S, That] extends Transformer[Combiner[(U, S), That], ZipAll[U, S, That]]

Attributes
protected[this]
Definition Classes
ParIterableLike

trait Accessor[R, Tp] extends ParSeqLike.Accessor[R, Tp]

Attributes
protected
Definition Classes
ParSeqLike

class Corresponds[S] extends Accessor[Boolean, Corresponds[S]]

Attributes
protected[this]
Definition Classes
ParSeqLike

abstract class Elements extends SeqSplitter[T] with scala.BufferedIterator[T]

Used to iterate elements using indices

Attributes
protected
Definition Classes
ParSeqLike

class IndexWhere extends Accessor[Int, IndexWhere]

Attributes
protected[this]
Definition Classes
ParSeqLike

class LastIndexWhere extends Accessor[Int, LastIndexWhere]

Attributes
protected[this]
Definition Classes
ParSeqLike

class Reverse[U >: T, This >: Repr] extends Transformer[Combiner[U, This], Reverse[U, This]]

Attributes
protected[this]
Definition Classes
ParSeqLike

class ReverseMap[S, That] extends Transformer[Combiner[S, That], ReverseMap[S, That]]

Attributes
protected[this]
Definition Classes
ParSeqLike

class SameElements[U >: T] extends Accessor[Boolean, SameElements[U]]

Attributes
protected[this]
Definition Classes
ParSeqLike

class SegmentLength extends Accessor[(Int, Boolean), SegmentLength]

Attributes
protected[this]
Definition Classes
ParSeqLike

trait Transformer[R, Tp] extends Accessor[R, Tp] with ParSeqLike.Transformer[R, Tp]

Attributes
protected
Definition Classes
ParSeqLike

class Updated[U >: T, That] extends Transformer[Combiner[U, That], Updated[U, That]]

Attributes
protected[this]
Definition Classes
ParSeqLike

class Zip[U >: T, S, That] extends Transformer[Combiner[(U, S), That], Zip[U, S, That]]

Attributes
protected[this]
Definition Classes
ParSeqLike

class Map[S] extends Task[Unit, Map[S]]

class ParArrayIterator extends SeqSplitter[T]

type SSCTask[R, Tp] = StrictSplitterCheckTask[R, Tp]

Definition Classes
ParIterableLike

class ScanToArray[U >: T] extends Task[Unit, ScanToArray[U]]

type SuperParIterator = IterableSplitter[T]

Attributes
protected[this]
Definition Classes
ParSeqLike

Value Members

final def !=(arg0: Any): Boolean

Test two objects for inequality.

returns

true if !(this == that), false otherwise.

Definition Classes
AnyRef → Any

final def ##(): Int

Equivalent to x.hashCode except for boxed numeric types and null. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null returns a hashcode where null.hashCode throws a NullPointerException.

returns

a hash value consistent with ==

Definition Classes
AnyRef → Any

def +(other: String): String

Implicit
This member is added by an implicit conversion from ParArray[T] to any2stringadd[ParArray[T]] performed by method any2stringadd in scala.Predef.
Definition Classes
any2stringadd

def ++[U >: T, That](that: GenTraversableOnce[U])(implicit bf: CanBuildFrom[ParArray[T], U, That]): That

Returns a new parallel iterable containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the parallel iterable is the most specific superclass encompassing the element types of the two operands.

That

the class of the returned collection. Where possible, That is the same class as the current collection class Repr, but this depends on the element type B being admissible for that class, which means that an implicit instance of type CanBuildFrom[Repr, B, That] is found.

that

the traversable to append.

bf

an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B.

returns

a new collection of type That which contains all elements of this parallel iterable followed by all elements of that.

Definition Classes
ParIterableLikeGenTraversableLike

def +:(elem: A): ParArray[A]

[use case]

A copy of the parallel array with an element prepended.

Note that :-ending operators are right associative (see example). A mnemonic for +: vs. :+ is: the COLon goes on the COLlection side.

Also, the original parallel array is not modified, so you will want to capture the result.

Example:

scala> val x = List(1)
x: List[Int] = List(1)

scala> val y = 2 +: x
y: List[Int] = List(2, 1)

scala> println(x)
List(1)
elem

the prepended element

returns

a new parallel array consisting of elem followed by all elements of this parallel array.

Definition Classes
ParSeqLikeGenSeqLike
Full Signature

def ->[B](y: B): (ParArray[T], B)

Implicit
This member is added by an implicit conversion from ParArray[T] to ArrowAssoc[ParArray[T]] performed by method ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc
Annotations
@inline()

def /:[S](z: S)(op: (S, T) ⇒ S): S

Applies a binary operator to a start value and all elements of this parallel iterable, going left to right.

Note: /: is alternate syntax for foldLeft; z /: xs is the same as xs foldLeft z.

Examples:

Note that the folding function used to compute b is equivalent to that used to compute c.

scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)

scala> val b = (5 /: a)(_+_)
b: Int = 15

scala> val c = (5 /: a)((x,y) => x + y)
c: Int = 15

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

z

the start value.

op

the binary operator.

returns

the result of inserting op between consecutive elements of this parallel iterable, going left to right with the start value z on the left:

op(...op(op(z, x_1), x_2), ..., x_n)

where x1, ..., xn are the elements of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableOnce

def :+(elem: A): ParArray[A]

[use case]

A copy of this parallel array with an element appended.

A mnemonic for +: vs. :+ is: the COLon goes on the COLlection side.

Note: will not terminate for infinite-sized collections.

Example:

scala> val a = List(1)
a: List[Int] = List(1)

scala> val b = a :+ 2
b: List[Int] = List(1, 2)

scala> println(a)
List(1)
elem

the appended element

returns

a new parallel array consisting of all elements of this parallel array followed by elem.

Definition Classes
ParSeqLikeGenSeqLike
Full Signature

def :\[S](z: S)(op: (T, S) ⇒ S): S

Applies a binary operator to all elements of this parallel iterable and a start value, going right to left.

Note: :\ is alternate syntax for foldRight; xs :\ z is the same as xs foldRight z.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

Examples:

Note that the folding function used to compute b is equivalent to that used to compute c.

scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)

scala> val b = (a :\ 5)(_+_)
b: Int = 15

scala> val c = (a :\ 5)((x,y) => x + y)
c: Int = 15
z

the start value

op

the binary operator

returns

the result of inserting op between consecutive elements of this parallel iterable, going right to left with the start value z on the right:

op(x_1, op(x_2, ... op(x_n, z)...))

where x1, ..., xn are the elements of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableOnce

final def ==(arg0: Any): Boolean

The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

returns

true if the receiver object is equivalent to the argument; false otherwise.

Definition Classes
AnyRef → Any

def aggregate[S](z: ⇒ S)(seqop: (S, T) ⇒ S, combop: (S, S) ⇒ S): S

Aggregates the results of applying an operator to subsequent elements.

This is a more general form of fold and reduce. It has similar semantics, but does not require the result to be a supertype of the element type. It traverses the elements in different partitions sequentially, using seqop to update the result, and then applies combop to results from different partitions. The implementation of this operation may operate on an arbitrary number of collection partitions, so combop may be invoked arbitrary number of times.

For example, one might want to process some elements and then produce a Set. In this case, seqop would process an element and append it to the set, while combop would concatenate two sets from different partitions together. The initial value z would be an empty set.

pc.aggregate(Set[Int]())(_ += process(_), _ ++ _)

Another example is calculating geometric mean from a collection of doubles (one would typically require big doubles for this).

S

the type of accumulated results

z

the initial value for the accumulated result of the partition - this will typically be the neutral element for the seqop operator (e.g. Nil for list concatenation or 0 for summation) and may be evaluated more than once

seqop

an operator used to accumulate results within a partition

combop

an associative operator used to combine results from different partitions

Definition Classes
ParIterableLikeGenTraversableOnce

def apply(i: Int): T

Selects an element by its index in the parallel array.

Example:

scala> val x = List(1, 2, 3, 4, 5)
x: List[Int] = List(1, 2, 3, 4, 5)

scala> x(3)
res1: Int = 4
returns

the element of this parallel array at index idx, where 0 indicates the first element.

Definition Classes
ParArrayParSeqGenSeqLike
Exceptions thrown

IndexOutOfBoundsException if idx does not satisfy 0 <= idx < length.

val arrayseq: ArraySeq[T]

final def asInstanceOf[T0]: T0

Cast the receiver object to be of type T0.

Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.

returns

the receiver object.

Definition Classes
Any
Exceptions thrown

ClassCastException if the receiver object is not an instance of the erasure of type T0.

def bf2seq[S, That](bf: CanBuildFrom[ParArray[T], S, That]): CanBuildFrom[ArraySeq[T], S, That]

Attributes
protected[this]
Definition Classes
ParIterableLike

implicit def builder2ops[Elem, To](cb: Builder[Elem, To]): BuilderOps[Elem, To]

Attributes
protected
Definition Classes
ParIterableLike

def canEqual(other: Any): Boolean

Definition Classes
ParIterableLike

def clone(): AnyRef

Create a copy of the receiver object.

The default implementation of the clone method is platform dependent.

returns

a copy of the receiver object.

Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws( ... ) @native()
Note

not specified by SLS as a member of AnyRef

def collect[B](pf: PartialFunction[A, B]): ParArray[B]

[use case]

Builds a new collection by applying a partial function to all elements of this parallel array on which the function is defined.

B

the element type of the returned collection.

pf

the partial function which filters and maps the parallel array.

returns

a new parallel array resulting from applying the given partial function pf to each element on which it is defined and collecting the results. The order of the elements is preserved.

Definition Classes
ParIterableLikeGenTraversableLike
Full Signature

def combinerFactory[S, That](cbf: () ⇒ Combiner[S, That]): CombinerFactory[S, That]

Attributes
protected[this]
Definition Classes
ParIterableLike

def combinerFactory: CombinerFactory[T, ParArray[T]]

Creates a combiner factory. Each combiner factory instance is used once per invocation of a parallel transformer method for a single collection.

The default combiner factory creates a new combiner every time it is requested, unless the combiner is thread-safe as indicated by its canBeShared method. In this case, the method returns a factory which returns the same combiner each time. This is typically done for concurrent parallel collections, the combiners of which allow thread safe access.

Attributes
protected[this]
Definition Classes
ParIterableLike

def companion: GenericCompanion[ParArray] with GenericParCompanion[ParArray]

The factory companion object that builds instances of class ParArray. (or its Iterable superclass where class ParArray is not a Seq.)

Definition Classes
ParArrayParSeqParSeqParIterableParIterableGenericParTemplateGenSeqGenIterableGenTraversableGenericTraversableTemplate

def copyToArray(xs: Array[A], start: Int, len: Int): Unit

[use case]

Copies the elements of this parallel array to an array. Fills the given array xs with at most len elements of this parallel array, starting at position start. Copying will stop once either the end of the current parallel array is reached, or the end of the target array is reached, or len elements have been copied.

Note: will not terminate for infinite-sized collections.

xs

the array to fill.

start

the starting index.

len

the maximal number of elements to copy.

Definition Classes
ParIterableLikeGenTraversableOnce
Full Signature

def copyToArray(xs: Array[A], start: Int): Unit

[use case]

Copies the elements of this parallel array to an array. Fills the given array xs with values of this parallel array, beginning at index start. Copying will stop once either the end of the current parallel array is reached, or the end of the target array is reached.

Note: will not terminate for infinite-sized collections.

xs

the array to fill.

start

the starting index.

Definition Classes
ParIterableLikeGenTraversableOnce
Full Signature

def copyToArray(xs: Array[A]): Unit

[use case]

Copies the elements of this parallel array to an array. Fills the given array xs with values of this parallel array. Copying will stop once either the end of the current parallel array is reached, or the end of the target array is reached.

Note: will not terminate for infinite-sized collections.

xs

the array to fill.

Definition Classes
ParIterableLikeGenTraversableOnce
Full Signature

def corresponds[S](that: GenSeq[S])(p: (T, S) ⇒ Boolean): Boolean

Tests whether every element of this parallel iterable relates to the corresponding element of another parallel sequence by satisfying a test predicate.

This method will use abort signalling capabilities. This means that splitters may send and read abort signals.

S

the type of the elements of that

that

the other parallel sequence

p

the test predicate, which relates elements from both sequences

returns

true if both parallel sequences have the same length and p(x, y) is true for all corresponding elements x of this parallel iterable and y of that, otherwise false

Definition Classes
ParSeqLikeGenSeqLike

def count(p: (T) ⇒ Boolean): Int

Counts the number of elements in the parallel iterable which satisfy a predicate.

p

the predicate used to test elements.

returns

the number of elements satisfying the predicate p.

Definition Classes
ParIterableLikeGenTraversableOnce

def debugBuffer: ArrayBuffer[String]

Definition Classes
ParIterableLike

implicit def delegatedSignalling2ops[PI <: DelegatedSignalling](it: PI): SignallingOps[PI]

Attributes
protected
Definition Classes
ParIterableLike

def diff(that: GenSeq[A]): ParArray[A]

[use case]

Computes the multiset difference between this parallel array and another sequence.

Note: will not terminate for infinite-sized collections.

that

the sequence of elements to remove

returns

a new parallel array which contains all elements of this parallel array except some of occurrences of elements that also appear in that. If an element value x appears n times in that, then the first n occurrences of x will not form part of the result, but any following occurrences will.

Definition Classes
ParSeqLikeGenSeqLike
Full Signature

def distinct: ParArray[T]

Builds a new parallel iterable from this parallel iterable without any duplicate elements.

Note: will not terminate for infinite-sized collections.

returns

A new parallel iterable which contains the first occurrence of every element of this parallel iterable.

Definition Classes
ParSeqLikeGenSeqLike

def down(p: IterableSplitter[_]): SeqSplitter[T]

Attributes
protected[this]
Definition Classes
ParSeqLike

def drop(n: Int): ParArray[T]

Selects all elements except first n ones.

Note: might return different results for different runs, unless the underlying collection type is ordered.

n

the number of elements to drop from this parallel iterable.

returns

a parallel iterable consisting of all elements of this parallel iterable except the first n ones, or else the empty parallel iterable, if this parallel iterable has less than n elements. If n is negative, don't drop any elements.

Definition Classes
ParIterableLikeGenTraversableLike

def dropWhile(pred: (T) ⇒ Boolean): ParArray[T]

Drops all elements in the longest prefix of elements that satisfy the predicate, and returns a collection composed of the remaining elements.

This method will use indexFlag signalling capabilities. This means that splitters may set and read the indexFlag state. The index flag is initially set to maximum integer value.

pred

the predicate used to test the elements

returns

a collection composed of all the elements after the longest prefix of elements in this parallel iterable that satisfy the predicate pred

Definition Classes
ParIterableLikeGenTraversableLike

def endsWith[S](that: GenSeq[S]): Boolean

Tests whether this parallel iterable ends with the given parallel sequence.

This method will use abort signalling capabilities. This means that splitters may send and read abort signals.

S

the type of the elements of that sequence

that

the sequence to test

returns

true if this parallel iterable has that as a suffix, false otherwise

Definition Classes
ParSeqLikeGenSeqLike

def ensuring(cond: (ParArray[T]) ⇒ Boolean, msg: ⇒ Any): ParArray[T]

Implicit
This member is added by an implicit conversion from ParArray[T] to Ensuring[ParArray[T]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring

def ensuring(cond: (ParArray[T]) ⇒ Boolean): ParArray[T]

Implicit
This member is added by an implicit conversion from ParArray[T] to Ensuring[ParArray[T]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring

def ensuring(cond: Boolean, msg: ⇒ Any): ParArray[T]

Implicit
This member is added by an implicit conversion from ParArray[T] to Ensuring[ParArray[T]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring

def ensuring(cond: Boolean): ParArray[T]

Implicit
This member is added by an implicit conversion from ParArray[T] to Ensuring[ParArray[T]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring

final def eq(arg0: AnyRef): Boolean

Tests whether the argument (that) is a reference to the receiver object (this).

The eq method implements an equivalence relation on non-null instances of AnyRef, and has three additional properties:

    It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false. null.eq(null) returns true.

When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).

returns

true if the argument is a reference to the receiver object; false otherwise.

Definition Classes
AnyRef

def equals(that: Any): Boolean

The equals method for arbitrary sequences. Compares this sequence to some other object.

that

The object to compare the sequence to

returns

true if that is a sequence that has the same elements as this sequence in the same order, false otherwise

Definition Classes
GenSeqLikeEqualsAny

def exists(p: (T) ⇒ Boolean): Boolean

Tests whether a predicate holds for some element of this parallel iterable.

This method will use abort signalling capabilities. This means that splitters may send and read abort signals.

p

a predicate used to test elements

returns

true if p holds for some element, false otherwise

Definition Classes
ParIterableLikeGenTraversableOnce

def filter(pred: (T) ⇒ Boolean): ParArray[T]

Selects all elements of this parallel iterable which satisfy a predicate.

pred

the predicate used to test elements.

returns

a new parallel iterable consisting of all elements of this parallel iterable that satisfy the given predicate p. Their order may not be preserved.

Definition Classes
ParIterableLikeGenTraversableLike

def filterNot(pred: (T) ⇒ Boolean): ParArray[T]

Selects all elements of this parallel iterable which do not satisfy a predicate.

pred

the predicate used to test elements.

returns

a new parallel iterable consisting of all elements of this parallel iterable that do not satisfy the given predicate p. Their order may not be preserved.

Definition Classes
ParIterableLikeGenTraversableLike

def finalize(): Unit

Called by the garbage collector on the receiver object when there are no more references to the object.

The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.

Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
Note

not specified by SLS as a member of AnyRef

def find(p: (T) ⇒ Boolean): Option[T]

Finds some element in the collection for which the predicate holds, if such an element exists. The element may not necessarily be the first such element in the iteration order.

If there are multiple elements obeying the predicate, the choice is nondeterministic.

This method will use abort signalling capabilities. This means that splitters may send and read abort signals.

p

predicate used to test the elements

returns

an option value with the element if such an element exists, or None otherwise

Definition Classes
ParIterableLikeGenTraversableOnce

def flatMap[B](f: (A) ⇒ GenTraversableOnce[B]): ParArray[B]

[use case]

Builds a new collection by applying a function to all elements of this parallel array and using the elements of the resulting collections.

For example:

def getWords(lines: Seq[String]): Seq[String] = lines flatMap (line => line split "\\W+")

The type of the resulting collection is guided by the static type of parallel array. This might cause unexpected results sometimes. For example:

// lettersOf will return a Seq[Char] of likely repeated letters, instead of a Set
def lettersOf(words: Seq[String]) = words flatMap (word => word.toSet)

// lettersOf will return a Set[Char], not a Seq
def lettersOf(words: Seq[String]) = words.toSet flatMap (word => word.toSeq)

// xs will be an Iterable[Int]
val xs = Map("a" -> List(11,111), "b" -> List(22,222)).flatMap(_._2)

// ys will be a Map[Int, Int]
val ys = Map("a" -> List(1 -> 11,1 -> 111), "b" -> List(2 -> 22,2 -> 222)).flatMap(_._2)
B

the element type of the returned collection.

f

the function to apply to each element.

returns

a new parallel array resulting from applying the given collection-valued function f to each element of this parallel array and concatenating the results.

Definition Classes
ParIterableLikeGenTraversableLike
Full Signature

def flatten[B]: ParArray[B]

[use case]

Converts this parallel array of traversable collections into a parallel array formed by the elements of these traversable collections.

The resulting collection's type will be guided by the static type of parallel array. For example:

val xs = List(
           Set(1, 2, 3),
           Set(1, 2, 3)
         ).flatten
// xs == List(1, 2, 3, 1, 2, 3)

val ys = Set(
           List(1, 2, 3),
           List(3, 2, 1)
         ).flatten
// ys == Set(1, 2, 3)
B

the type of the elements of each traversable collection.

returns

a new parallel array resulting from concatenating all element parallel arrays.

Definition Classes
GenericTraversableTemplate
Full Signature

def fold[U >: T](z: U)(op: (U, U) ⇒ U): U

Folds the elements of this sequence using the specified associative binary operator. The order in which the elements are reduced is unspecified and may be nondeterministic.

Note this method has a different signature than the foldLeft and foldRight methods of the trait Traversable. The result of folding may only be a supertype of this parallel collection's type parameter T.

U

a type parameter for the binary operator, a supertype of T.

z

a neutral element for the fold operation, it may be added to the result an arbitrary number of times, not changing the result (e.g. Nil for list concatenation, 0 for addition, or 1 for multiplication)

op

a binary operator that must be associative

returns

the result of applying fold operator op between all the elements and z

Definition Classes
ParIterableLikeGenTraversableOnce

def foldLeft[S](z: S)(op: (S, T) ⇒ S): S

Applies a binary operator to a start value and all elements of this parallel iterable, going left to right.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

z

the start value.

op

the binary operator.

returns

the result of inserting op between consecutive elements of this parallel iterable, going left to right with the start value z on the left:

op(...op(z, x_1), x_2, ..., x_n)

where x1, ..., xn are the elements of this parallel iterable. Returns z if this parallel iterable is empty.

Definition Classes
ParIterableLikeGenTraversableOnce

def foldRight[S](z: S)(op: (T, S) ⇒ S): S

Applies a binary operator to all elements of this parallel iterable and a start value, going right to left.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

z

the start value.

op

the binary operator.

returns

the result of inserting op between consecutive elements of this parallel iterable, going right to left with the start value z on the right:

op(x_1, op(x_2, ... op(x_n, z)...))

where x1, ..., xn are the elements of this parallel iterable. Returns z if this parallel iterable is empty.

Definition Classes
ParIterableLikeGenTraversableOnce

def forall(p: (T) ⇒ Boolean): Boolean

Tests whether a predicate holds for all elements of this parallel iterable.

This method will use abort signalling capabilities. This means that splitters may send and read abort signals.

p

a predicate used to test elements

returns

true if p holds for all elements, false otherwise

Definition Classes
ParIterableLikeGenTraversableOnce

def foreach[U](f: (T) ⇒ U): Unit

Applies a function f to all the elements of parallel iterable in an undefined order.

U

the result type of the function applied to each element, which is always discarded

f

function applied to each element

Definition Classes
ParIterableLikeGenTraversableLikeGenTraversableOnce

def formatted(fmtstr: String): String

Returns string formatted according to given format string. Format strings are as for String.format (@see java.lang.String.format).

Implicit
This member is added by an implicit conversion from ParArray[T] to StringFormat[ParArray[T]] performed by method StringFormat in scala.Predef.
Definition Classes
StringFormat
Annotations
@inline()

def genericBuilder[B]: Combiner[B, ParArray[B]]

The generic builder that builds instances of Traversable at arbitrary element types.

Definition Classes
GenericParTemplateGenericTraversableTemplate

def genericCombiner[B]: Combiner[B, ParArray[B]]

Definition Classes
GenericParTemplate

final def getClass(): Class[_]

Returns the runtime class representation of the object.

returns

a class object corresponding to the runtime type of the receiver.

Definition Classes
AnyRef → Any
Annotations
@native()

def groupBy[K](f: (T) ⇒ K): immutable.ParMap[K, ParArray[T]]

Partitions this parallel iterable into a map of parallel iterables according to some discriminator function.

Note: this method is not re-implemented by views. This means when applied to a view it will always force the view and return a new parallel iterable.

K

the type of keys returned by the discriminator function.

f

the discriminator function.

returns

A map from keys to parallel iterables such that the following invariant holds:

(xs groupBy f)(k) = xs filter (x => f(x) == k)

That is, every key k is bound to a parallel iterable of those elements x for which f(x) equals k.

Definition Classes
ParIterableLikeGenTraversableLike

def hasDefiniteSize: Boolean

Tests whether this parallel iterable is known to have a finite size. All strict collections are known to have finite size. For a non-strict collection such as Stream, the predicate returns true if all elements have been computed. It returns false if the stream is not yet evaluated to the end. Non-empty Iterators usually return false even if they were created from a collection with a known finite size.

Note: many collection methods will not work on collections of infinite sizes. The typical failure mode is an infinite loop. These methods always attempt a traversal without checking first that hasDefiniteSize returns true. However, checking hasDefiniteSize can provide an assurance that size is well-defined and non-termination is not a concern.

returns

true if this collection is known to have finite size, false otherwise.

Definition Classes
ParIterableLikeGenTraversableOnce

def hashCode(): Int

Hashcodes for GenSeq produce a value from the hashcodes of all the elements of the general sequence.

returns

the hash code value for this object.

Definition Classes
GenSeqLikeAny

Selects the first element of this parallel iterable.

Note: might return different results for different runs, unless the underlying collection type is ordered.

returns

the first element of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableLike
Exceptions thrown

NoSuchElementException if the parallel iterable is empty.

def headOption: Option[T]

Optionally selects the first element.

Note: might return different results for different runs, unless the underlying collection type is ordered.

returns

the first element of this parallel iterable if it is nonempty, None if it is empty.

Definition Classes
ParIterableLikeGenTraversableLike

def indexOf(elem: T, from: Int): Int

[use case]

Finds index of first occurrence of some value in this parallel array after or at some start index.

Note: may not terminate for infinite-sized collections.

elem

the element value to search for.

from

the start index

returns

the index >= from of the first element of this parallel array that is equal (as determined by ==) to elem, or -1, if none exists.

Definition Classes
GenSeqLike
Full Signature

def indexOf(elem: T): Int

[use case]

Finds index of first occurrence of some value in this parallel array.

Note: may not terminate for infinite-sized collections.

elem

the element value to search for.

returns

the index of the first element of this parallel array that is equal (as determined by ==) to elem, or -1, if none exists.

Definition Classes
GenSeqLike
Full Signature

def indexWhere(p: (T) ⇒ Boolean, from: Int): Int

Finds the first element satisfying some predicate.

This method will use indexFlag signalling capabilities. This means that splitters may set and read the indexFlag state.

The index flag is initially set to maximum integer value.

p

the predicate used to test the elements

from

the starting offset for the search

returns

the index >= from of the first element of this parallel iterable that satisfies the predicate p, or -1, if none exists

Definition Classes
ParSeqLikeGenSeqLike

def indexWhere(p: (T) ⇒ Boolean): Int

Finds index of first element satisfying some predicate.

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

the index of the first element of this general sequence that satisfies the predicate p, or -1, if none exists.

Definition Classes
GenSeqLike

def init: ParArray[T]

Selects all elements except the last.

Note: might return different results for different runs, unless the underlying collection type is ordered.

returns

a parallel iterable consisting of all elements of this parallel iterable except the last one.

Definition Classes
ParIterableLikeGenTraversableLike
Exceptions thrown

UnsupportedOperationException if the parallel iterable is empty.

def initTaskSupport(): Unit

Attributes
protected
Definition Classes
ParIterableLike

def intersect(that: scala.Seq[T]): ParArray[T]

[use case]

Computes the multiset intersection between this parallel array and another sequence.

Note: may not terminate for infinite-sized collections.

that

the sequence of elements to intersect with.

returns

a new parallel array which contains all elements of this parallel array which also appear in that. If an element value x appears n times in that, then the first n occurrences of x will be retained in the result, but any following occurrences will be omitted.

Definition Classes
ParSeqLikeGenSeqLike
Full Signature

def isDefinedAt(idx: Int): Boolean

Tests whether this general sequence contains given index.

The implementations of methods apply and isDefinedAt turn a Seq[A] into a PartialFunction[Int, A].

idx

the index to test

returns

true if this general sequence contains an element at position idx, false otherwise.

Definition Classes
GenSeqLike

def isEmpty: Boolean

Tests whether the parallel iterable is empty.

Note: Implementations in subclasses that are not repeatedly traversable must take care not to consume any elements when isEmpty is called.

returns

true if the parallel iterable contains no elements, false otherwise.

Definition Classes
ParIterableLikeGenTraversableOnce

final def isInstanceOf[T0]: Boolean

Test whether the dynamic type of the receiver object is T0.

Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.

returns

true if the receiver object is an instance of erasure of type T0; false otherwise.

Definition Classes
Any

def isStrictSplitterCollection: Boolean

Denotes whether this parallel collection has strict splitters.

This is true in general, and specific collection instances may choose to override this method. Such collections will fail to execute methods which rely on splitters being strict, i.e. returning a correct value in the remaining method.

This method helps ensure that such failures occur on method invocations, rather than later on and in unpredictable ways.

Definition Classes
ParIterableLike

final def isTraversableAgain: Boolean

Tests whether this parallel iterable can be repeatedly traversed.

returns

true

Definition Classes
ParIterableLikeGenTraversableLikeGenTraversableOnce

def iterator: PreciseSplitter[T]

Creates a new split iterator used to traverse the elements of this collection.

By default, this method is implemented in terms of the protected splitter method.

returns

a split iterator

Definition Classes
ParSeqLikeParIterableLikeGenIterableLike

def last: T

Selects the last element.

Note: might return different results for different runs, unless the underlying collection type is ordered.

returns

The last element of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableLike
Exceptions thrown

NoSuchElementException If the parallel iterable is empty.

def lastIndexOf(elem: T, end: Int): Int

[use case]

Finds index of last occurrence of some value in this parallel array before or at a given end index.

elem

the element value to search for.

end

the end index.

returns

the index <= end of the last element of this parallel array that is equal (as determined by ==) to elem, or -1, if none exists.

Definition Classes
GenSeqLike
Full Signature

def lastIndexOf(elem: T): Int

[use case]

Finds index of last occurrence of some value in this parallel array.

Note: will not terminate for infinite-sized collections.

elem

the element value to search for.

returns

the index of the last element of this parallel array that is equal (as determined by ==) to elem, or -1, if none exists.

Definition Classes
GenSeqLike
Full Signature

def lastIndexWhere(p: (T) ⇒ Boolean, end: Int): Int

Finds the last element satisfying some predicate.

This method will use indexFlag signalling capabilities. This means that splitters may set and read the indexFlag state.

The index flag is initially set to minimum integer value.

p

the predicate used to test the elements

end

the maximum offset for the search

returns

the index <= end of the first element of this parallel iterable that satisfies the predicate p, or -1, if none exists

Definition Classes
ParSeqLikeGenSeqLike

def lastIndexWhere(p: (T) ⇒ Boolean): Int

Finds index of last element satisfying some predicate.

Note: will not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

the index of the last element of this general sequence that satisfies the predicate p, or -1, if none exists.

Definition Classes
GenSeqLike

def lastOption: Option[T]

Optionally selects the last element.

Note: might return different results for different runs, unless the underlying collection type is ordered.

returns

the last element of this parallel iterable$ if it is nonempty, None if it is empty.

Definition Classes
ParIterableLikeGenTraversableLike

def length: Int

The length of the parallel array.

Note: will not terminate for infinite-sized collections.

Note: xs.length and xs.size yield the same result.

returns

the number of elements in this parallel array.

Definition Classes
ParArrayGenSeqLike
Exceptions thrown

IllegalArgumentException if the length of the sequence cannot be represented in an Int, for example, (-1 to Int.MaxValue).length.

def map[B](f: (A) ⇒ B): ParArray[B]

[use case]

Builds a new collection by applying a function to all elements of this parallel array.

B

the element type of the returned collection.

f

the function to apply to each element.

returns

a new parallel array resulting from applying the given function f to each element of this parallel array and collecting the results.

Definition Classes
ParArrayParIterableLikeGenTraversableLike
Full Signature

def max: A

[use case]

Finds the largest element.

returns

the largest element of this parallel array.

Definition Classes
ParIterableLikeGenTraversableOnce
Full Signature
Exceptions thrown

UnsupportedOperationException if this parallel array is empty.

def maxBy[B](f: (A) ⇒ B): A

[use case]

Finds the first element which yields the largest value measured by function f.

B

The result type of the function f.

f

The measuring function.

returns

the first element of this parallel array with the largest value measured by function f.

Definition Classes
ParIterableLikeGenTraversableOnce
Full Signature
Exceptions thrown

UnsupportedOperationException if this parallel array is empty.

def min: A

[use case]

Finds the smallest element.

returns

the smallest element of this parallel array

Definition Classes
ParIterableLikeGenTraversableOnce
Full Signature
Exceptions thrown

UnsupportedOperationException if this parallel array is empty.

def minBy[B](f: (A) ⇒ B): A

[use case]

Finds the first element which yields the smallest value measured by function f.

B

The result type of the function f.

f

The measuring function.

returns

the first element of this parallel array with the smallest value measured by function f.

Definition Classes
ParIterableLikeGenTraversableOnce
Full Signature
Exceptions thrown

UnsupportedOperationException if this parallel array is empty.

def mkString: String

Displays all elements of this parallel iterable in a string.

returns

a string representation of this parallel iterable. In the resulting string the string representations (w.r.t. the method toString) of all elements of this parallel iterable follow each other without any separator string.

Definition Classes
ParIterableLikeGenTraversableOnce

def mkString(sep: String): String

Displays all elements of this parallel iterable in a string using a separator string.

sep

the separator string.

returns

a string representation of this parallel iterable. In the resulting string the string representations (w.r.t. the method toString) of all elements of this parallel iterable are separated by the string sep.

Definition Classes
ParIterableLikeGenTraversableOnce
Example:

    List(1, 2, 3).mkString("|") = "1|2|3"

def mkString(start: String, sep: String, end: String): String

Displays all elements of this parallel iterable in a string using start, end, and separator strings.

start

the starting string.

sep

the separator string.

end

the ending string.

returns

a string representation of this parallel iterable. The resulting string begins with the string start and ends with the string end. Inside, the string representations (w.r.t. the method toString) of all elements of this parallel iterable are separated by the string sep.

Definition Classes
ParIterableLikeGenTraversableOnce
Example:

    List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"

final def ne(arg0: AnyRef): Boolean

Equivalent to !(this eq that).

returns

true if the argument is not a reference to the receiver object; false otherwise.

Definition Classes
AnyRef

def newBuilder: Builder[T, ParArray[T]]

The builder that builds instances of type Traversable[A]

Attributes
protected[this]
Definition Classes
GenericParTemplateGenericTraversableTemplateHasNewBuilder

def newCombiner: Combiner[T, ParArray[T]]

Attributes
protected[this]
Definition Classes
GenericParTemplateHasNewCombiner

def nonEmpty: Boolean

Tests whether the parallel iterable is not empty.

returns

true if the parallel iterable contains at least one element, false otherwise.

Definition Classes
ParIterableLikeGenTraversableOnce

final def notify(): Unit

Wakes up a single thread that is waiting on the receiver object's monitor.

Definition Classes
AnyRef
Annotations
@native()
Note

not specified by SLS as a member of AnyRef

final def notifyAll(): Unit

Wakes up all threads that are waiting on the receiver object's monitor.

Definition Classes
AnyRef
Annotations
@native()
Note

not specified by SLS as a member of AnyRef

def padTo(len: Int, elem: A): ParArray[A]

[use case]

A copy of this parallel array with an element value appended until a given target length is reached.

len

the target length

elem

the padding value

returns

a new parallel array consisting of all elements of this parallel array followed by the minimal number of occurrences of elem so that the resulting parallel array has a length of at least len.

Definition Classes
ParSeqLikeGenSeqLike
Full Signature

def par: ParArray[T]

Returns a parallel implementation of this collection.

For most collection types, this method creates a new parallel collection by copying all the elements. For these collection, par takes linear time. Mutable collections in this category do not produce a mutable parallel collection that has the same underlying dataset, so changes in one collection will not be reflected in the other one.

Specific collections (e.g. ParArray or mutable.ParHashMap) override this default behaviour by creating a parallel collection which shares the same underlying dataset. For these collections, par takes constant or sublinear time.

All parallel collections return a reference to themselves.

returns

a parallel implementation of this collection

Definition Classes
ParIterableLikeCustomParallelizableParallelizable

def parCombiner: Combiner[T, ParArray[T]]

The default par implementation uses the combiner provided by this method to create a new parallel collection.

returns

a combiner for the parallel collection of type ParRepr

Attributes
protected[this]
Definition Classes
CustomParallelizableParallelizable

def partition(pred: (T) ⇒ Boolean): (ParArray[T], ParArray[T])

Partitions this parallel iterable in two parallel iterables according to a predicate.

pred

the predicate on which to partition.

returns

a pair of parallel iterables: the first parallel iterable consists of all elements that satisfy the predicate p and the second parallel iterable consists of all elements that don't. The relative order of the elements in the resulting parallel iterables may not be preserved.

Definition Classes
ParIterableLikeGenTraversableLike

def patch(from: Int, that: GenSeq[A], replaced: Int): ParArray[A]

[use case]

Produces a new parallel array where a slice of elements in this parallel array is replaced by another sequence.

from

the index of the first replaced element

replaced

the number of elements to drop in the original parallel array

returns

a new parallel array consisting of all elements of this parallel array except that replaced elements starting from from are replaced by patch.

Definition Classes
ParSeqLikeGenSeqLike
Full Signature

def prefixLength(p: (T) ⇒ Boolean): Int

Returns the length of the longest prefix whose elements all satisfy some predicate.

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

the length of the longest prefix of this general sequence such that every element of the segment satisfies the predicate p.

Definition Classes
GenSeqLike

def product: A

[use case]

Multiplies up the elements of this collection.

returns

the product of all elements in this parallel array of numbers of type Int. Instead of Int, any other type T with an implicit Numeric[T] implementation can be used as element type of the parallel array and as result type of product. Examples of such types are: Long, Float, Double, BigInt.

Definition Classes
ParIterableLikeGenTraversableOnce
Full Signature

def reduce[U >: T](op: (U, U) ⇒ U): U

Reduces the elements of this sequence using the specified associative binary operator.

The order in which operations are performed on elements is unspecified and may be nondeterministic.

Note this method has a different signature than the reduceLeft and reduceRight methods of the trait Traversable. The result of reducing may only be a supertype of this parallel collection's type parameter T.

U

A type parameter for the binary operator, a supertype of T.

op

A binary operator that must be associative.

returns

The result of applying reduce operator op between all the elements if the collection is nonempty.

Definition Classes
ParIterableLikeGenTraversableOnce
Exceptions thrown

UnsupportedOperationException if this parallel iterable is empty.

def reduceLeft[U >: T](op: (U, T) ⇒ U): U

Definition Classes
ParIterableLike

def reduceLeftOption[U >: T](op: (U, T) ⇒ U): Option[U]

Optionally applies a binary operator to all elements of this parallel iterable, going left to right.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

op

the binary operator.

returns

an option value containing the result of reduceLeft(op) if this parallel iterable is nonempty, None otherwise.

Definition Classes
ParIterableLikeGenTraversableOnce

def reduceOption[U >: T](op: (U, U) ⇒ U): Option[U]

Optionally reduces the elements of this sequence using the specified associative binary operator.

The order in which operations are performed on elements is unspecified and may be nondeterministic.

Note this method has a different signature than the reduceLeftOption and reduceRightOption methods of the trait Traversable. The result of reducing may only be a supertype of this parallel collection's type parameter T.

U

A type parameter for the binary operator, a supertype of T.

op

A binary operator that must be associative.

returns

An option value containing result of applying reduce operator op between all the elements if the collection is nonempty, and None otherwise.

Definition Classes
ParIterableLikeGenTraversableOnce

def reduceRight[U >: T](op: (T, U) ⇒ U): U

Applies a binary operator to all elements of this parallel iterable, going right to left.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

op

the binary operator.

returns

the result of inserting op between consecutive elements of this parallel iterable, going right to left:

op(x_1, op(x_2, ..., op(x_{n-1}, x_n)...))

where x1, ..., xn are the elements of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableOnce
Exceptions thrown

UnsupportedOperationException if this parallel iterable is empty.

def reduceRightOption[U >: T](op: (T, U) ⇒ U): Option[U]

Optionally applies a binary operator to all elements of this parallel iterable, going right to left.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

op

the binary operator.

returns

an option value containing the result of reduceRight(op) if this parallel iterable is nonempty, None otherwise.

Definition Classes
ParIterableLikeGenTraversableOnce

def repr: ParArray[T]

Definition Classes
ParIterableLikeGenTraversableLike

def reuse[S, That](oldc: Option[Combiner[S, That]], newc: Combiner[S, That]): Combiner[S, That]

Optionally reuses an existing combiner for better performance. By default it doesn't - subclasses may override this behaviour. The provided combiner oldc that can potentially be reused will be either some combiner from the previous computational task, or None if there was no previous phase (in which case this method must return newc).

oldc

The combiner that is the result of the previous task, or None if there was no previous task.

newc

The new, empty combiner that can be used.

returns

Either newc or oldc.

Attributes
protected
Definition Classes
ParIterableLike

def reverse: ParArray[T]

Returns new parallel iterable with elements in reversed order.

Note: will not terminate for infinite-sized collections.

returns

A new parallel iterable with all elements of this parallel iterable in reversed order.

Definition Classes
ParSeqLikeGenSeqLike

def reverseMap[B](f: (A) ⇒ B): ParArray[B]

[use case]

Builds a new collection by applying a function to all elements of this parallel array and collecting the results in reversed order.

Note: will not terminate for infinite-sized collections.

Note: xs.reverseMap(f) is the same as xs.reverse.map(f) but might be more efficient.

B

the element type of the returned collection.

f

the function to apply to each element.

returns

a new parallel array resulting from applying the given function f to each element of this parallel array and collecting the results in reversed order.

Definition Classes
ParSeqLikeGenSeqLike
Full Signature

def sameElements(that: GenIterable[A]): Boolean

[use case]

Checks if the other iterable collection contains the same elements in the same order as this parallel array.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Note: will not terminate for infinite-sized collections.

that

the collection to compare with.

returns

true, if both collections contain the same elements in the same order, false otherwise.

Definition Classes
ParSeqLikeParIterableLikeGenIterableLike
Full Signature

def scan(z: T)(op: (T, T) ⇒ T): ParArray[T]

[use case]

Computes a prefix scan of the elements of the collection.

Note: The neutral element z may be applied more than once.

z

neutral element for the operator op

op

the associative operator for the scan

returns

a new parallel array containing the prefix scan of the elements in this parallel array

Definition Classes
ParArrayParIterableLikeGenTraversableLike
Full Signature

def scanBlockSize: Int

Attributes
protected[this]
Definition Classes
ParIterableLike

def scanLeft[S, That](z: S)(op: (S, T) ⇒ S)(implicit bf: CanBuildFrom[ParArray[T], S, That]): That

Produces a collection containing cumulative results of applying the operator going left to right.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered.

That

the actual type of the resulting collection

z

the initial value

op

the binary operator applied to the intermediate result and the element

bf

an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B.

returns

collection with intermediate results

Definition Classes
ParIterableLikeGenTraversableLike

def scanRight[S, That](z: S)(op: (T, S) ⇒ S)(implicit bf: CanBuildFrom[ParArray[T], S, That]): That

Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Example:

List(1, 2, 3, 4).scanRight(0)(_ + _) == List(10, 9, 7, 4, 0)
That

the actual type of the resulting collection

z

the initial value

op

the binary operator applied to the intermediate result and the element

bf

an implicit value of class CanBuildFrom which determines the result class That from the current representation type Repr and the new element type B.

returns

collection with intermediate results

Definition Classes
ParIterableLikeGenTraversableLike

def segmentLength(p: (T) ⇒ Boolean, from: Int): Int

Returns the length of the longest segment of elements starting at a given position satisfying some predicate.

This method will use indexFlag signalling capabilities. This means that splitters may set and read the indexFlag state.

The index flag is initially set to maximum integer value.

p

the predicate used to test the elements

from

the starting offset for the search

returns

the length of the longest segment of elements starting at from and satisfying the predicate

Definition Classes
ParSeqLikeGenSeqLike

def seq: ArraySeq[T]

def sequentially[S, That <: Parallel](b: (ArraySeq[T]) ⇒ Parallelizable[S, That]): ParArray[T]

Attributes
protected[this]
Definition Classes
ParIterableLike

def size: Int

The size of this parallel iterable.

Note: will not terminate for infinite-sized collections.

returns

the number of elements in this parallel iterable.

Definition Classes
ParSeqLikeGenTraversableLikeGenTraversableOnce

def sizeHintIfCheap: Int

The size of this collection or iterator, if it can be cheaply computed

returns

the number of elements in this collection or iterator, or -1 if the size cannot be determined cheaply

Attributes
protected[collection]
Definition Classes
GenTraversableOnce

def slice(unc_from: Int, unc_until: Int): ParArray[T]

Selects an interval of elements. The returned collection is made up of all elements x which satisfy the invariant:

from <= indexOf(x) < until

Note: might return different results for different runs, unless the underlying collection type is ordered.

unc_from

the lowest index to include from this parallel iterable.

unc_until

the lowest index to EXCLUDE from this parallel iterable.

returns

a parallel iterable containing the elements greater than or equal to index from extending up to (but not including) index until of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableLike

def span(pred: (T) ⇒ Boolean): (ParArray[T], ParArray[T])

Splits this parallel iterable into a prefix/suffix pair according to a predicate.

This method will use indexFlag signalling capabilities. This means that splitters may set and read the indexFlag state. The index flag is initially set to maximum integer value.

pred

the predicate used to test the elements

returns

a pair consisting of the longest prefix of the collection for which all the elements satisfy pred, and the rest of the collection

Definition Classes
ParIterableLikeGenTraversableLike

def splitAt(n: Int): (ParArray[T], ParArray[T])

Splits this parallel iterable into two at a given position. Note: c splitAt n is equivalent to (but possibly more efficient than) (c take n, c drop n).

Note: might return different results for different runs, unless the underlying collection type is ordered.

n

the position at which to split.

returns

a pair of parallel iterables consisting of the first n elements of this parallel iterable, and the other elements.

Definition Classes
ParIterableLikeGenTraversableLike

def splitter: ParArrayIterator

A more refined version of the iterator found in the ParallelIterable trait, this iterator can be split into arbitrary subsets of iterators.

returns

an iterator that can be split into subsets of precise size

Attributes
protected[parallel]
Definition Classes
ParArrayParSeqLikeParIterableLike

def startsWith[S](that: GenSeq[S], offset: Int): Boolean

Tests whether this parallel iterable contains the given sequence at a given index.

This method will use abort signalling capabilities. This means that splitters may send and read abort signals.

S

the element type of that parallel sequence

that

the parallel sequence this sequence is being searched for

offset

the starting offset for the search

returns

true if there is a sequence that starting at offset in this sequence, false otherwise

Definition Classes
ParSeqLikeGenSeqLike

def startsWith[B](that: GenSeq[B]): Boolean

Tests whether this general sequence starts with the given sequence.

that

the sequence to test

returns

true if this collection has that as a prefix, false otherwise.

Definition Classes
GenSeqLike

def stringPrefix: String

Defines the prefix of this object's toString representation.

returns

a string representation which starts the result of toString applied to this parallel iterable. By default the string prefix is the simple name of the collection class parallel iterable.

Definition Classes
ParSeqParIterableGenTraversableLike

def sum: A

[use case]

Sums up the elements of this collection.

returns

the sum of all elements in this parallel array of numbers of type Int. Instead of Int, any other type T with an implicit Numeric[T] implementation can be used as element type of the parallel array and as result type of sum. Examples of such types are: Long, Float, Double, BigInt.

Definition Classes
ParIterableLikeGenTraversableOnce
Full Signature

final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef

def tail: ParArray[T]

Selects all elements except the first.

Note: might return different results for different runs, unless the underlying collection type is ordered.

returns

a parallel iterable consisting of all elements of this parallel iterable except the first one.

Definition Classes
ParIterableLikeGenTraversableLike
Exceptions thrown

UnsupportedOperationException if the parallel iterable is empty.

def take(n: Int): ParArray[T]

Selects first n elements.

Note: might return different results for different runs, unless the underlying collection type is ordered.

n

the number of elements to take from this parallel iterable.

returns

a parallel iterable consisting only of the first n elements of this parallel iterable, or else the whole parallel iterable, if it has less than n elements. If n is negative, returns an empty parallel iterable.

Definition Classes
ParIterableLikeGenTraversableLike

def takeWhile(pred: (T) ⇒ Boolean): ParArray[T]

Takes the longest prefix of elements that satisfy the predicate.

This method will use indexFlag signalling capabilities. This means that splitters may set and read the indexFlag state. The index flag is initially set to maximum integer value.

pred

the predicate used to test the elements

returns

the longest prefix of this parallel iterable of elements that satisfy the predicate pred

Definition Classes
ParIterableLikeGenTraversableLike

implicit def task2ops[R, Tp](tsk: SSCTask[R, Tp]): TaskOps[R, Tp]

Attributes
protected
Definition Classes
ParIterableLike

def tasksupport: TaskSupport

The task support object which is responsible for scheduling and load-balancing tasks to processors.

Definition Classes
ParIterableLike
See also

scala.collection.parallel.TaskSupport

def tasksupport_=(ts: TaskSupport): Unit

Changes the task support object which is responsible for scheduling and load-balancing tasks to processors.

A task support object can be changed in a parallel collection after it has been created, but only during a quiescent period, i.e. while there are no concurrent invocations to parallel collection methods.

Here is a way to change the task support of a parallel collection:

import scala.collection.parallel._
val pc = mutable.ParArray(1, 2, 3)
pc.tasksupport = new ForkJoinTaskSupport(
  new java.util.concurrent.ForkJoinPool(2))
Definition Classes
ParIterableLike
See also

scala.collection.parallel.TaskSupport

def to[Col[_]]: Col[A]

[use case]

Converts this parallel array into another by copying all elements.

Note: will not terminate for infinite-sized collections.

Col

The collection type to build.

returns

a new collection containing all elements of this parallel array.

Definition Classes
ParIterableLikeGenTraversableOnce
Full Signature

def toArray: Array[A]

[use case]

Converts this parallel array to an array.

Note: will not terminate for infinite-sized collections.

returns

an array containing all elements of this parallel array. An ClassTag must be available for the element type of this parallel array.

Definition Classes
ParIterableLikeGenTraversableOnce
Full Signature

def toBuffer[U >: T]: Buffer[U]

Uses the contents of this parallel iterable to create a new mutable buffer.

Note: will not terminate for infinite-sized collections.

returns

a buffer containing all elements of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableOnce

def toIndexedSeq: immutable.IndexedSeq[T]

Converts this parallel iterable to an indexed sequence.

Note: will not terminate for infinite-sized collections.

returns

an indexed sequence containing all elements of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableOnce

def toIterable: ParIterable[T]

Converts this parallel iterable to an iterable collection. Note that the choice of target Iterable is lazy in this default implementation as this TraversableOnce may be lazy and unevaluated (i.e. it may be an iterator which is only traversable once).

Note: will not terminate for infinite-sized collections.

returns

an Iterable containing all elements of this parallel iterable.

Definition Classes
ParIterableParIterableLikeGenTraversableOnce

def toIterator: scala.Iterator[T]

Returns an Iterator over the elements in this parallel iterable. Will return the same Iterator if this instance is already an Iterator.

Note: will not terminate for infinite-sized collections.

returns

an Iterator containing all elements of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableOnce

def toList: List[T]

Converts this parallel iterable to a list.

Note: will not terminate for infinite-sized collections.

returns

a list containing all elements of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableOnce

def toMap[T, U]: collection.Map[T, U]

[use case]

Converts this parallel array to a map. This method is unavailable unless the elements are members of Tuple2, each ((T, U)) becoming a key-value pair in the map. Duplicate keys will be overwritten by later keys: if this is an unordered collection, which key is in the resulting map is undefined.

Note: will not terminate for infinite-sized collections.

returns

a map of type immutable.Map[T, U] containing all key/value pairs of type (T, U) of this parallel array.

Definition Classes
ParIterableLikeGenTraversableOnce
Full Signature

def toParArray: ParArray[T]

Implicit
This member is added by an implicit conversion from ParArray[T] to CollectionsHaveToParArray[ParArray[T], T] performed by method CollectionsHaveToParArray in scala.collection.parallel. This conversion will take place only if an implicit value of type (ParArray[T]) ⇒ GenTraversableOnce[T] is in scope.
Definition Classes
CollectionsHaveToParArray

def toParCollection[U >: T, That](cbf: () ⇒ Combiner[U, That]): That

Attributes
protected
Definition Classes
ParIterableLike

def toParMap[K, V, That](cbf: () ⇒ Combiner[(K, V), That])(implicit ev: <:<[T, (K, V)]): That

Attributes
protected
Definition Classes
ParIterableLike

def toSeq: ParSeq[T]

Converts this mutable parallel sequence to a sequence. As with toIterable, it's lazy in this default implementation, as this TraversableOnce may be lazy and unevaluated.

Note: will not terminate for infinite-sized collections.

returns

a sequence containing all elements of this mutable parallel sequence.

Definition Classes
ParSeqParSeqLikeParIterableParIterableLikeGenSeqLikeGenTraversableOnce

def toSet[U >: T]: immutable.ParSet[U]

Converts this parallel iterable to a set.

Note: will not terminate for infinite-sized collections.

returns

a set containing all elements of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableOnce

def toStream: Stream[T]

Converts this parallel iterable to a stream.

returns

a stream containing all elements of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableOnce

def toString(): String

Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.

returns

a String representation of the object.

Definition Classes
ParSeqParSeqLikeParIterableLike → AnyRef → Any

def toTraversable: GenTraversable[T]

Converts this parallel iterable to an unspecified Traversable. Will return the same collection if this instance is already Traversable.

Note: will not terminate for infinite-sized collections.

returns

a Traversable containing all elements of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableOnce

def toVector: Vector[T]

Converts this parallel iterable to a Vector.

Note: will not terminate for infinite-sized collections.

returns

a vector containing all elements of this parallel iterable.

Definition Classes
ParIterableLikeGenTraversableOnce

def transpose[B](implicit asTraversable: (T) ⇒ GenTraversableOnce[B]): ParArray[ParArray[B]]

Transposes this collection of traversable collections into a collection of collections.

The resulting collection's type will be guided by the static type of collection. For example:

val xs = List(
           Set(1, 2, 3),
           Set(4, 5, 6)).transpose
// xs == List(
//         List(1, 4),
//         List(2, 5),
//         List(3, 6))

val ys = Vector(
           List(1, 2, 3),
           List(4, 5, 6)).transpose
// ys == Vector(
//         Vector(1, 4),
//         Vector(2, 5),
//         Vector(3, 6))
B

the type of the elements of each traversable collection.

asTraversable

an implicit conversion which asserts that the element type of this collection is a Traversable.

returns

a two-dimensional collection of collections which has as nth row the nth column of this collection.

Definition Classes
GenericTraversableTemplate
Annotations
@migration
Migration

(Changed in version 2.9.0) transpose throws an IllegalArgumentException if collections are not uniformly sized.

Exceptions thrown

IllegalArgumentException if all collections in this collection are not of the same size.

def union(that: GenSeq[T]): ParArray[T]

[use case]

Produces a new sequence which contains all elements of this parallel array and also all elements of a given sequence. xs union ys is equivalent to xs ++ ys.

Another way to express this is that xs union ys computes the order-preserving multi-set union of xs and ys. union is hence a counter-part of diff and intersect which also work on multi-sets.

Note: will not terminate for infinite-sized collections.

that

the sequence to add.

returns

a new parallel array which contains all elements of this parallel array followed by all elements of that.

Definition Classes
GenSeqLike
Full Signature

def unzip[A1, A2](implicit asPair: (T) ⇒ (A1, A2)): (ParArray[A1], ParArray[A2])

Converts this collection of pairs into two collections of the first and second half of each pair.

val xs = Traversable(
           (1, "one"),
           (2, "two"),
           (3, "three")).unzip
// xs == (Traversable(1, 2, 3),
//        Traversable(one, two, three))
A1

the type of the first half of the element pairs

A2

the type of the second half of the element pairs

asPair

an implicit conversion which asserts that the element type of this collection is a pair.

returns

a pair of collections, containing the first, respectively second half of each element pair of this collection.

Definition Classes
GenericTraversableTemplate

def unzip3[A1, A2, A3](implicit asTriple: (T) ⇒ (A1, A2, A3)): (ParArray[A1], ParArray[A2], ParArray[A3])

Converts this collection of triples into three collections of the first, second, and third element of each triple.

val xs = Traversable(
           (1, "one", '1'),
           (2, "two", '2'),
           (3, "three", '3')).unzip3
// xs == (Traversable(1, 2, 3),
//        Traversable(one, two, three),
//        Traversable(1, 2, 3))
A1

the type of the first member of the element triples

A2

the type of the second member of the element triples

A3

the type of the third member of the element triples

asTriple

an implicit conversion which asserts that the element type of this collection is a triple.

returns

a triple of collections, containing the first, second, respectively third member of each element triple of this collection.

Definition Classes
GenericTraversableTemplate

def update(i: Int, elem: T): Unit

Definition Classes
ParArrayParSeq

def updated(index: Int, elem: A): ParArray[A]

[use case]

A copy of this parallel array with one single replaced element.

index

the position of the replacement

elem

the replacing element

returns

a copy of this parallel array with the element at position index replaced by elem.

Definition Classes
ParSeqLikeGenSeqLike
Full Signature

final def wait(): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... ) @native()

def withFilter(pred: (T) ⇒ Boolean): ParArray[T]

Definition Classes
ParIterableLike

def wrap[R](body: ⇒ R): NonDivisible[R]

Attributes
protected
Definition Classes
ParIterableLike

def zip[B](that: GenIterable[B]): ParArray[(A, B)]

[use case]

Returns a parallel array formed from this parallel array and another iterable collection by combining corresponding elements in pairs. If one of the two collections is longer than the other, its remaining elements are ignored.

Note: might return different results for different runs, unless the underlying collection type is ordered.

B

the type of the second half of the returned pairs

that

The iterable providing the second half of each result pair

returns

a new parallel array containing pairs consisting of corresponding elements of this parallel array and that. The length of the returned collection is the minimum of the lengths of this parallel array and that.

Definition Classes
ParSeqLikeParIterableLikeGenIterableLike
Full Signature

def zipAll[B](that: Iterable[B], thisElem: A, thatElem: B): ParArray[(A, B)]

[use case]

Returns a parallel array formed from this parallel array and another iterable collection by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements are used to extend the shorter collection to the length of the longer.

Note: might return different results for different runs, unless the underlying collection type is ordered.

B

the type of the second half of the returned pairs

that

The iterable providing the second half of each result pair

thisElem

the element to be used to fill up the result if this parallel array is shorter than that.

thatElem

the element to be used to fill up the result if that is shorter than this parallel array.

returns

a new parallel array containing pairs consisting of corresponding elements of this parallel array and that. The length of the returned collection is the maximum of the lengths of this parallel array and that. If this parallel array is shorter than that, thisElem values are used to pad the result. If that is shorter than this parallel array, thatElem values are used to pad the result.

Definition Classes
ParIterableLikeGenIterableLike
Full Signature

def zipWithIndex: ParArray[(A, Int)]

[use case]

Zips this parallel array with its indices.

Note: might return different results for different runs, unless the underlying collection type is ordered.

returns

A new parallel array containing pairs consisting of all elements of this parallel array paired with their index. Indices start at 0.

Definition Classes
ParIterableLikeGenIterableLike
Full Signature
Example:

    List("a", "b", "c").zipWithIndex = List(("a", 0), ("b", 1), ("c", 2))

def [B](y: B): (ParArray[T], B)

Implicit
This member is added by an implicit conversion from ParArray[T] to ArrowAssoc[ParArray[T]] performed by method ArrowAssoc in scala.Predef.
Definition Classes
ArrowAssoc

© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.12.9/scala/collection/parallel/mutable/ParArray.html