Standard accessor task that iterates over the elements of the collection.
Performs two tasks in parallel, and waits for both to finish.
Parallel iterators are split iterators that have additional accessor and
transformer methods defined in terms of methods next
and hasNext
.
Sequentially performs one task after another.
A stackable modification that ensures signal contexts get passed along the iterators.
The size of this parallel iterable.
The size of this parallel iterable.
Note: will not terminate for infinite-sized collections.
the number of elements in this parallel iterable.
Creates a new parallel iterator used to traverse the elements of this parallel collection.
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.
a parallel iterator
Test two objects for inequality.
Test two objects for inequality.
true
if !(this == that), false otherwise.
Equivalent to x.hashCode
except for boxed numeric types.
Equivalent to x.hashCode
except for boxed numeric types.
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.
a hash value consistent with ==
Computes the intersection between this set and another set.
Computes the intersection between this set and another set.
Note: Same as intersect
.
the set to intersect with.
a new set consisting of all elements that are both in this
set and in the given set that
.
The difference of this set and another set.
The difference of this set and another set.
Note: Same as diff
.
the set of elements to exclude.
a set containing those elements of this
set that are not also contained in the given set that
.
[use case] Concatenates this parallel iterable with the elements of a traversable collection.
Concatenates this parallel iterable with the elements of a traversable collection.
the element type of the returned collection.
the traversable to append.
a new collection of type That
which contains all elements
of this parallel iterable followed by all elements of that
.
Concatenates this parallel iterable with the elements of a traversable collection.
Concatenates this parallel iterable with the elements of a traversable collection.
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.
the traversable to append.
an implicit value of class CanBuildFrom
which determines
the result class That
from the current representation type Repr
and
and the new element type B
.
a new collection of type That
which contains all elements
of this parallel iterable followed by all elements of that
.
Applies a binary operator to a start value and all elements of this parallel iterable, going left to right.
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
.
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.
the start value.
the binary operator.
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 x,,1,,, ..., x,,n,,
are the elements of this parallel iterable.
A syntactic sugar for out of order folding.
A syntactic sugar for out of order folding. See fold
.
Applies a binary operator to all elements of this parallel iterable and a start value, going right to left.
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.
the start value
the binary operator
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 x,,1,,, ..., x,,n,,
are the elements of this parallel iterable.
Test two objects for equality.
Test two objects for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
Aggregates the results of applying an operator to subsequent elements.
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).
the type of accumulated results
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)
an operator used to accumulate results within a partition
an associative operator used to combine results from different partitions
Composes two instances of Function1 in a new Function1, with this function applied first.
Composes two instances of Function1 in a new Function1, with this function applied first.
the result type of function g
a function R => A
a new function f
such that f(x) == g(apply(x))
Tests if some element is contained in this set.
Tests if some element is contained in this set.
This method is equivalent to contains
. It allows sets to be interpreted as predicates.
the element to test for membership.
true
if elem
is contained in this set, false
otherwise.
Cast the receiver object to be of type 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.
the receiver object.
Create a copy of the receiver object.
[use case] Builds a new collection by applying a partial function to all elements of this parallel iterable on which the function is defined.
Builds a new collection by applying a partial function to all elements of this parallel iterable on which the function is defined.
the element type of the returned collection.
the partial function which filters and maps the parallel iterable.
a new collection of type That
resulting from applying the partial function
pf
to each element on which it is defined and collecting the results.
The order of the elements is preserved.
Builds a new collection by applying a partial function to all elements of this parallel iterable on which the function is defined.
Builds a new collection by applying a partial function to all elements of this parallel iterable on which the function is defined.
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.
the partial function which filters and maps the parallel iterable.
an implicit value of class CanBuildFrom
which determines
the result class That
from the current representation type Repr
and
and the new element type B
.
a new collection of type That
resulting from applying the partial function
pf
to each element on which it is defined and collecting the results.
The order of the elements is preserved.
The factory companion object that builds instances of class ParIterable.
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.
Composes two instances of Function1 in a new Function1, with this function applied last.
the type to which function g
can be applied
a function A => T1
a new function f
such that f(x) == apply(g(x))
[use case] Copies values of this parallel iterable to an array.
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.
the array to fill.
the starting index.
Copies values of this parallel iterable to an array.
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.
the array to fill.
the starting index.
[use case] Copies values of this parallel iterable to an array.
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.
the array to fill.
Copies values of this parallel iterable to an array.
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.
the array to fill.
Counts the number of elements in the parallel iterable which satisfy a predicate.
Counts the number of elements in the parallel iterable which satisfy a predicate.
the predicate used to test elements.
the number of elements satisfying the predicate p
.
Computes the difference of this set and another set.
Computes the difference of this set and another set.
the set of elements to exclude.
a set containing those elements of this
set that are not also contained in the given set that
.
Selects all elements except first n ones.
Selects all elements except first n ones.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the number of elements to drop from this parallel iterable.
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.
Drops all elements in the longest prefix of elements that satisfy the predicate, and returns a collection composed of the remaining elements.
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.
the predicate used to test the elements
a collection composed of all the elements after the longest prefix of elements
in this parallel iterable that satisfy the predicate pred
Tests whether the argument (arg0
) is a reference to the receiver object (this
).
Tests whether the argument (arg0
) 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:
x
and y
of type AnyRef
, multiple invocations of
x.eq(y)
consistently returns true
or consistently returns false
.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
).
true
if the argument is a reference to the receiver object; false
otherwise.
Compares this set with another object for equality.
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.
the other object
true
if that
is a set which contains the same elements
as this set.
Tests whether a predicate holds for some element of this parallel iterable.
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.
true if p
holds for some element, false otherwise
Selects all elements of this parallel iterable which satisfy a predicate.
Selects all elements of this parallel iterable which satisfy a predicate.
a new parallel iterable consisting of all elements of this parallel iterable that satisfy the given
predicate p
. Their order may not be preserved.
Selects all elements of this parallel iterable which do not satisfy a predicate.
Selects all elements of this parallel iterable which do not satisfy a predicate.
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.
Called by the garbage collector on the receiver object when there are no more references to the object.
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.
Finds some element in the collection for which the predicate holds, if such an element exists.
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.
an option value with the element if such an element exists, or None
otherwise
[use case] Builds a new collection by applying a function to all elements of this parallel iterable and concatenating the results.
Builds a new collection by applying a function to all elements of this parallel iterable and concatenating the results.
the element type of the returned collection.
the function to apply to each element.
a new collection of type That
resulting from applying the given collection-valued function
f
to each element of this parallel iterable and concatenating the results.
Builds a new collection by applying a function to all elements of this parallel iterable and concatenating the results.
Builds a new collection by applying a function to all elements of this parallel iterable and concatenating the results.
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.
the function to apply to each element.
an implicit value of class CanBuildFrom
which determines
the result class That
from the current representation type Repr
and
and the new element type B
.
a new collection of type That
resulting from applying the given collection-valued function
f
to each element of this parallel iterable and concatenating the results.
[use case] Converts this parallel iterable of traversable collections into a parallel iterable in which all element collections are concatenated.
Converts this parallel iterable of traversable collections into a parallel iterable in which all element collections are concatenated.
the type of the elements of each traversable collection.
a new parallel iterable resulting from concatenating all element parallel iterables.
Converts this parallel iterable of traversable collections into a parallel iterable in which all element collections are concatenated.
Converts this parallel iterable of traversable collections into a parallel iterable in which all element collections are concatenated.
the type of the elements of each traversable collection.
an implicit conversion which asserts that the element
type of this parallel iterable is a Traversable
.
a new parallel iterable resulting from concatenating all element parallel iterables.
Folds the elements of this sequence using the specified associative binary operator.
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
.
a type parameter for the binary operator, a supertype of T
.
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)
a binary operator that must be associative
the result of applying fold operator op
between all the elements and z
Applies a binary operator to a start value and all elements of this parallel iterable, going left to right.
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.
the start value.
the binary operator.
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 x,,1,,, ..., x,,n,,
are the elements of this parallel iterable.
Applies a binary operator to all elements of this parallel iterable and a start value, going right to left.
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.
the start value.
the binary operator.
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 x,,1,,, ..., x,,n,,
are the elements of this parallel iterable.
Tests whether a predicate holds for all elements of this parallel iterable.
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.
true if p
holds for all elements, false otherwise
Applies a function f
to all the elements of parallel iterable in a sequential order.
Applies a function f
to all the elements of parallel iterable in a sequential order.
the result type of the function applied to each element, which is always discarded
function applied to each element
The generic builder that builds instances of ParIterable at arbitrary element types.
The generic builder that builds instances of ParIterable at arbitrary element types.
A representation that corresponds to the dynamic class of the receiver object.
A representation that corresponds to the dynamic class of the receiver object.
The nature of the representation is platform dependent.
a representation that corresponds to the dynamic class of the receiver object.
Partitions this parallel iterable into a map of parallel iterables according to some discriminator function.
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.
the type of keys returned by the discriminator function.
the discriminator function.
A map from keys to parallel iterables such that the following invariant holds:
(xs partition 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
.
The hashCode method for reference types.
The hashCode method for reference types. See hashCode in Any.
the hash code value for this object.
Computes the intersection between this set and another set.
Computes the intersection between this set and another set.
the set to intersect with.
a new set consisting of all elements that are both in this
set and in the given set that
.
Tests whether the parallel iterable is empty.
Tests whether the parallel iterable is empty.
true
if the parallel iterable contains no elements, false
otherwise.
Test whether the dynamic type of the receiver object is T0
.
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.
true
if the receiver object is an instance of erasure of type T0
; false
otherwise.
Denotes whether this parallel collection has strict splitters.
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 parallel iterable can be repeatedly traversed.
Tests whether this parallel iterable can be repeatedly traversed.
true
Creates a new split iterator used to traverse the elements of this collection.
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.
a split iterator
[use case] Builds a new collection by applying a function to all elements of this parallel iterable.
Builds a new collection by applying a function to all elements of this parallel iterable.
the element type of the returned collection.
the function to apply to each element.
a new collection of type That
resulting from applying the given function
f
to each element of this parallel iterable and collecting the results.
Builds a new collection by applying a function to all elements of this parallel iterable.
Builds a new collection by applying a function to all elements of this parallel iterable.
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.
the function to apply to each element.
an implicit value of class CanBuildFrom
which determines
the result class That
from the current representation type Repr
and
and the new element type B
.
a new collection of type That
resulting from applying the given function
f
to each element of this parallel iterable and collecting the results.
[use case] Finds the largest element.
Finds the largest element.
the largest element of this parallel iterable with respect to the ordering cmp
.
Finds the largest element.
Finds the largest element.
the largest element of this parallel iterable with respect to the ordering cmp
.
[use case] Finds the smallest element.
Finds the smallest element.
the smallest element of this parallel iterable with respect to the ordering cmp
.
Finds the smallest element.
Finds the smallest element.
the smallest element of this parallel iterable with respect to the ordering cmp
.
Displays all elements of this parallel iterable in a string.
Displays all elements of this parallel iterable in a string.
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.
Displays all elements of this parallel iterable in a string using a separator string.
Displays all elements of this parallel iterable in a string using a separator string.
the separator string.
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
.
List(1, 2, 3).mkString("|") = "1|2|3"
Displays all elements of this parallel iterable in a string using start, end, and separator strings.
Displays all elements of this parallel iterable in a string using start, end, and separator strings.
the starting string.
the separator string.
the ending string.
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
.
List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
Equivalent to !(this eq that)
.
Equivalent to !(this eq that)
.
true
if the argument is not a reference to the receiver object; false
otherwise.
The builder that builds instances of type ParIterable[A]
The builder that builds instances of type ParIterable[A]
Tests whether the parallel iterable is not empty.
Tests whether the parallel iterable is not empty.
true
if the parallel iterable contains at least one element, false
otherwise.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
Returns a parallel implementation of this collection.
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.
a parallel implementation of this collection
The default par
implementation uses the combiner provided by this method
to create a new parallel collection.
The default par
implementation uses the combiner provided by this method
to create a new parallel collection.
a combiner for the parallel collection of type ParRepr
Partitions this parallel iterable in two parallel iterables according to a predicate.
Partitions this parallel iterable in two parallel iterables according to a predicate.
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.
[use case] Multiplies up the elements of this collection.
Multiplies up the elements of this collection.
the product of all elements of this parallel iterable with respect to the *
operator in num
.
Multiplies up the elements of this collection.
Multiplies up the elements of this collection.
an implicit parameter defining a set of numeric operations
which includes the *
operator to be used in forming the product.
the product of all elements of this parallel iterable with respect to the *
operator in num
.
Reduces the elements of this sequence using the specified associative binary operator.
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
.
A type parameter for the binary operator, a supertype of T
.
A binary operator that must be associative.
The result of applying reduce operator op
between all the elements if the collection is nonempty.
Optionally applies a binary operator to all elements of this parallel iterable, going left to right.
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.
the binary operator.
an option value containing the result of reduceLeft(op)
is this parallel iterable is nonempty,
None
otherwise.
Optionally reduces the elements of this sequence using the specified associative binary operator.
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
.
A type parameter for the binary operator, a supertype of T
.
A binary operator that must be associative.
An option value containing result of applying reduce operator op
between all
the elements if the collection is nonempty, and None
otherwise.
Applies a binary operator to all elements of this parallel iterable, going right to left.
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.
the binary operator.
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 x,,1,,, ..., x,,n,,
are the elements of this parallel iterable.
Optionally applies a binary operator to all elements of this parallel iterable, going right to left.
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.
the binary operator.
an option value containing the result of reduceRight(op)
is this parallel iterable is nonempty,
None
otherwise.
Optionally reuses an existing combiner for better performance.
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
).
The combiner that is the result of the previous task, or None
if there was no previous task.
The new, empty combiner that can be used.
Either newc
or oldc
.
[use case] Checks if the other iterable collection contains the same elements in the same order as this parallel iterable.
Checks if the other iterable collection contains the same elements in the same order as this parallel iterable.
the collection to compare with.
true
, if both collections contain the same elements in the same order, false
otherwise.
Checks if the other iterable collection contains the same elements in the same order as this parallel iterable.
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.
the collection to compare with.
true
, if both collections contain the same elements in the same order, false
otherwise.
[use case] Computes a prefix scan of the elements of the collection.
Computes a prefix scan of the elements of the collection.
neutral element for the operator op
the associative operator for the scan
a collection containing the prefix scan of the elements in the original collection
Computes a prefix scan of the elements of the collection.
Computes a prefix scan of the elements of the collection.
Note: The neutral element z
may be applied more than once.
element type of the resulting collection
type of the resulting collection
neutral element for the operator op
the associative operator for the scan
a collection containing the prefix scan of the elements in the original collection
Produces a collection containing cummulative results of applying the operator going left to right.
Produces a collection containing cummulative 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.
the actual type of the resulting collection
the initial value
the binary operator applied to the intermediate result and the element
an implicit value of class CanBuildFrom
which determines
the result class That
from the current representation type Repr
and
and the new element type B
.
collection with intermediate results
Produces a collection containing cummulative results of applying the operator going right to left.
Produces a collection containing cummulative results of applying the operator going right to left. The head of the collection is the last cummulative 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)
the actual type of the resulting collection
the initial value
the binary operator applied to the intermediate result and the element
an implicit value of class CanBuildFrom
which determines
the result class That
from the current representation type Repr
and
and the new element type B
.
collection with intermediate results
Selects an interval of elements.
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.
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.
Splits this parallel iterable into a prefix/suffix pair according to a predicate.
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.
the predicate used to test the elements
a pair consisting of the longest prefix of the collection for which all
the elements satisfy pred
, and the rest of the collection
Splits this parallel iterable into two at a given position.
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.
the position at which to split.
a pair of parallel iterables consisting of the first n
elements of this parallel iterable, and the other elements.
Defines the prefix of this object's toString
representation.
Defines the prefix of this object's toString
representation.
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.
Tests whether this set is a subset of another set.
Tests whether this set is a subset of another set.
the set to test.
true
if this set is a subset of that
, i.e. if
every element of this set is also an element of that
.
[use case] Sums up the elements of this collection.
Sums up the elements of this collection.
the sum of all elements of this parallel iterable with respect to the +
operator in num
.
Sums up the elements of this collection.
Sums up the elements of this collection.
an implicit parameter defining a set of numeric operations
which includes the +
operator to be used in forming the sum.
the sum of all elements of this parallel iterable with respect to the +
operator in num
.
Selects all elements except the first.
Selects all elements except the first.
Note: might return different results for different runs, unless the underlying collection type is ordered.
a parallel iterable consisting of all elements of this parallel iterable except the first one.
Selects first n elements.
Selects first n elements.
Note: might return different results for different runs, unless the underlying collection type is ordered.
Tt number of elements to take from this parallel iterable.
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.
Takes the longest prefix of elements that satisfy the predicate.
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 predicate used to test the elements
the longest prefix of this parallel iterable of elements that satisy the predicate pred
Some minimal number of elements after which this collection should be handled sequentially by different processors.
Some minimal number of elements after which this collection should be handled sequentially by different processors.
This method depends on the size of the collection and the parallelism level, which are both specified as arguments.
the size based on which to compute the threshold
the parallelism level based on which to compute the threshold
the maximum number of elements for performing operations sequentially
[use case] Converts this parallel iterable to an array.
Converts this parallel iterable to an array.
Note: will not terminate for infinite-sized collections.
an array containing all elements of this parallel iterable.
Converts this parallel iterable to an array.
Converts this parallel iterable to an array.
Note: will not terminate for infinite-sized collections.
an array containing all elements of this parallel iterable.
Converts this parallel iterable to a mutable buffer.
Converts this parallel iterable to a mutable buffer.
Note: will not terminate for infinite-sized collections.
a buffer containing all elements of this parallel iterable.
Converts this parallel iterable to an indexed sequence.
Converts this parallel iterable to an indexed sequence.
Note: will not terminate for infinite-sized collections.
an indexed sequence containing all elements of this parallel iterable.
Converts this parallel iterable to an iterable collection.
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.
an Iterable
containing all elements of this parallel iterable.
Returns an Iterator over the elements in this parallel iterable.
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.
an Iterator containing all elements of this parallel iterable.
Converts this parallel iterable to a list.
Converts this parallel iterable to a list.
Note: will not terminate for infinite-sized collections.
a list containing all elements of this parallel iterable.
[use case] Converts this parallel iterable to a map.
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.
a map containing all elements of this parallel iterable.
Converts this parallel iterable to a map.
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.
a map containing all elements of this parallel iterable.
Converts this parallel iterable to a sequence.
Converts this parallel iterable 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.
a sequence containing all elements of this parallel iterable.
Converts this parallel iterable to a set.
Converts this parallel iterable to a set.
Note: will not terminate for infinite-sized collections.
a set containing all elements of this parallel iterable.
Converts this parallel iterable to a stream.
Converts this parallel iterable to a stream.
Note: will not terminate for infinite-sized collections.
a stream containing all elements of this parallel iterable.
Creates a String representation of this object.
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.
a String representation of the object.
Converts this parallel iterable to an unspecified Traversable.
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.
a Traversable containing all elements of this parallel iterable.
Transposes this parallel iterable of traversable collections into a parallel iterable of parallel iterables.
Transposes this parallel iterable of traversable collections into a parallel iterable of parallel iterables.
the type of the elements of each traversable collection.
an implicit conversion which asserts that the
element type of this parallel iterable is a Traversable
.
a two-dimensional parallel iterable of parallel iterables which has as nth row the nth column of this parallel iterable.
"As of 2.9, transpose throws an exception if collections are not uniformly sized."
Computes the union between of set and another set.
Computes the union between of set and another set.
the set to form the union with.
a new set consisting of all elements that are in this
set or in the given set that
.
Converts this parallel iterable of pairs into two collections of the first and second half of each pair.
Converts this parallel iterable of pairs into two collections of the first and second half of each pair.
an implicit conversion which asserts that the element type of this parallel iterable is a pair.
a pair parallel iterables, containing the first, respectively second half of each element pair of this parallel iterable.
Converts this parallel iterable of triples into three collections of the first, second, and third element of each triple.
Converts this parallel iterable of triples into three collections of the first, second, and third element of each triple.
a triple parallel iterables, containing the first, second, respectively third member of each element triple of this parallel iterable.
[use case] Returns a parallel iterable formed from this parallel iterable and another iterable collection by combining corresponding elements in pairs.
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.
the type of the second half of the returned pairs
The iterable providing the second half of each result pair
a new collection of type That
containing pairs consisting of
corresponding elements of this parallel iterable and that
. The length
of the returned collection is the minimum of the lengths of this parallel iterable and that
.
Returns a parallel iterable formed from this parallel iterable and another iterable collection by combining corresponding elements in pairs.
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.
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 (A1, B)
being admissible for that class,
which means that an implicit instance of type CanBuildFrom[Repr, (A1, B), That]
.
is found.
The iterable providing the second half of each result pair
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type (A1, B)
.
a new collection of type That
containing pairs consisting of
corresponding elements of this parallel iterable and that
. The length
of the returned collection is the minimum of the lengths of this parallel iterable and that
.
[use case] Returns a parallel iterable formed from this parallel iterable and another iterable collection by combining corresponding elements in pairs.
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.
the iterable providing the second half of each result pair
the element to be used to fill up the result if this parallel iterable is shorter than that
.
the element to be used to fill up the result if that
is shorter than this parallel iterable.
a new collection of type That
containing pairs consisting of
corresponding elements of this parallel iterable and that
. The length
of the returned collection is the maximum of the lengths of this parallel iterable and that
.
If this parallel iterable is shorter than that
, thisElem
values are used to pad the result.
If that
is shorter than this parallel iterable, thatElem
values are used to pad the result.
Returns a parallel iterable formed from this parallel iterable and another iterable collection by combining corresponding elements in pairs.
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.
the iterable providing the second half of each result pair
the element to be used to fill up the result if this parallel iterable is shorter than that
.
the element to be used to fill up the result if that
is shorter than this parallel iterable.
a new collection of type That
containing pairs consisting of
corresponding elements of this parallel iterable and that
. The length
of the returned collection is the maximum of the lengths of this parallel iterable and that
.
If this parallel iterable is shorter than that
, thisElem
values are used to pad the result.
If that
is shorter than this parallel iterable, thatElem
values are used to pad the result.
[use case] Zips this parallel iterable with its indices.
Zips this parallel iterable with its indices.
A new collection of type That
containing pairs consisting of all elements of this
parallel iterable paired with their index. Indices start at 0
.
Zips this parallel iterable with its indices.
Zips this parallel iterable with its indices.
Note: might return different results for different runs, unless the underlying collection type is ordered.
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 (A1, Int)
being admissible for that class,
which means that an implicit instance of type CanBuildFrom[Repr, (A1, Int), That]
.
is found.
A new collection of type That
containing pairs consisting of all elements of this
parallel iterable paired with their index. Indices start at 0
.
Computes the union between this set and another set.
Computes the union between this set and another set.
Note: Same as union
.
the set to form the union with.
a new set consisting of all elements that are in this
set or in the given set that
.
A template trait for parallel sets.
The higher-order functions passed to certain operations may contain side-effects. Since implementations of bulk operations may not be sequential, this means that side-effects may not be predictable and may produce data-races, deadlocks or invalidation of state if care is not taken. It is up to the programmer to either avoid using side-effects or to use some form of synchronization when accessing mutable data.
the element type of the set
2.9