ParSet

The size of this general collection.

Note: will not terminate for infinite-sized collections.

Creates a new parallel iterator used to traverse the elements of this parallel collection. This iterator is more specific than the iterator of the returned by iterator, and augmented with additional accessor and transformer methods.

Computes the intersection between this set and another set.

Note: Same as intersect.

The difference of this set and another set.

Note: Same as diff.

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.

Example:

scala> val a = LinkedList(1)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(1)

scala> val b = LinkedList(2)
b: scala.collection.mutable.LinkedList[Int] = LinkedList(2)

scala> val c = a ++ b
c: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)

scala> val d = LinkedList('a')
d: scala.collection.mutable.LinkedList[Char] = LinkedList(a)

scala> val e = c ++ d
e: scala.collection.mutable.LinkedList[AnyVal] = LinkedList(1, 2, a)

Applies a binary operator to a start value and all elements of this general iterable collection , 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 = LinkedList(1,2,3,4)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(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.

Applies a binary operator to all elements of this general iterable collection 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 = LinkedList(1,2,3,4)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4)

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

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

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 list, while combop would concatenate two lists 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).

Composes two instances of Function1 in a new Function1, with this function applied first.

Tests if some element is contained in this set.

This method is equivalent to contains. It allows sets to be interpreted as predicates.

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

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.

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

Composes two instances of Function1 in a new Function1, with this function applied last.

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

Note: will not terminate for infinite-sized collections.

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

Note: will not terminate for infinite-sized collections.

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

Computes the difference of this set and another set.

Selects all elements except first n ones.

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

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.

Compares this set with another object for equality.

Note: This operation contains an unchecked cast: if that is a set, it will assume with an unchecked cast that it has the same element type as this set. Any subsequent ClassCastException is treated as a false result.

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

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

Selects all elements of this general iterable collection which satisfy a predicate.

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

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.

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

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

The resulting collection's type will be guided by the static type of parallel iterable. 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)

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.

Applies a binary operator to a start value and all elements of this general iterable collection , 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.

Applies a binary operator to all elements of this general iterable collection 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.

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

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

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

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

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

Partitions this general iterable collection into a map of general iterable collection s 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 general iterable collection .

Selects the first element of this general iterable collection .

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

Optionally selects the first element.

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

Selects all elements except the last.

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

Computes the intersection between this set and another set.

Tests whether the general iterable collection is empty.

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.

Tests whether this general iterable collection can be repeatedly traversed.

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.

Selects the last element.

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

Optionally selects the last element.

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

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

Finds the largest element.

Finds the smallest element.

Displays all elements of this general iterable collection in a string.

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

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

The builder that builds instances of type CC[A]

Tests whether the general iterable collection is not empty.

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.

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

Partitions this general iterable collection in two general iterable collection s according to a predicate.

Multiplies up the elements of this collection.

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.

Optionally applies a binary operator to all elements of this general iterable collection , 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.

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.

Applies a binary operator to all elements of this general iterable collection , 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.

Optionally applies a binary operator to all elements of this general iterable collection , 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.

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).

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

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

Note: will not terminate for infinite-sized collections.

Computes a prefix scan of the elements of the collection.

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

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.

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)

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.

Splits this general iterable collection 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.

Splits this general iterable collection 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.

Defines the prefix of this object's toString representation.

Tests whether this set is a subset of another set.

Sums up the elements of this collection.

Selects all elements except the first.

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

Selects first n elements.

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

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.

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

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 scala.concurrent.forkjoin.ForkJoinPool(2))

Converts this parallel iterable into another by copying all elements.

Note: will not terminate for infinite-sized collections.

Converts this parallel iterable to an array.

Note: will not terminate for infinite-sized collections.

Converts this general iterable collection to a mutable buffer.

Note: will not terminate for infinite-sized collections.

Converts this general iterable collection to an indexed sequence.

Note: will not terminate for infinite-sized collections.

Converts this general iterable collection 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 Iterator over the elements in this general iterable collection . Will return the same Iterator if this instance is already an Iterator.

Note: will not terminate for infinite-sized collections.

Converts this general iterable collection to a list.

Note: will not terminate for infinite-sized collections.

Converts this parallel iterable 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.

Converts this general iterable collection 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.

Converts this general iterable collection to a set.

Note: will not terminate for infinite-sized collections.

Converts this general iterable collection to a stream.

Note: will not terminate for infinite-sized collections.

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

Note: will not terminate for infinite-sized collections.

Converts this general iterable collection to a Vector.

Note: will not terminate for infinite-sized collections.

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))

Computes the union between of set and another set.

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

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

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

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

Returns a parallel iterable formed from this parallel iterable 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.

Returns a parallel iterable formed from this parallel iterable 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.

Zips this parallel iterable with its indices.

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

Computes the union between this set and another set.

Note: Same as union.