Standard accessor task that iterates over the elements of the collection.
Performs two tasks in parallel, and waits for both to finish.
Sequentially performs one task after another.
The size of this general set.
The size of this general set.
Note: will not terminate for infinite-sized collections.
the number of elements in this general set.
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
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 general set. By default the string prefix is the
simple name of the collection class general set.
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 and null
.
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
.
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] Returns a new general set containing the elements from the left hand operand followed by the elements from the right hand operand.
Returns a new general set containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the general set 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)
the element type of the returned collection.
the traversable to append.
a new general set which contains all elements of this general set
followed by all elements of that
.
Applies a binary operator to a start value and all elements of this general set, going left to right.
Applies a binary operator to a start value and all elements of this general set, 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.
the start value.
the binary operator.
the result of inserting op
between consecutive elements of this general set,
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 general set.
Applies a binary operator to all elements of this general set and a start value, going right to left.
Applies a binary operator to all elements of this general set 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
the start value
the binary operator
the result of inserting op
between consecutive elements of this general set,
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 general set.
Test two objects for equality.
Test two objects for equality.
The expression x == that
is equivalent to if (x eq null) that eq null else x.equals(that)
.
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.
if the receiver object is not an instance of the erasure of type T0
.
Create a copy of the receiver object.
[use case] Builds a new collection by applying a partial function to all elements of this general set on which the function is defined.
Builds a new collection by applying a partial function to all elements of this general set on which the function is defined.
the element type of the returned collection.
the partial function which filters and maps the general set.
a new general set 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.
Creates a combiner factory.
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.
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 general set to an array.
Copies values of this general set to an array.
Fills the given array xs
with values of this general set, beginning at index start
.
Copying will stop once either the end of the current general set 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 general set to an array.
Copies values of this general set to an array.
Fills the given array xs
with values of this general set.
Copying will stop once either the end of the current general set 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 general set which satisfy a predicate.
Counts the number of elements in the general set 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 general set.
a general set consisting of all elements of this general set except the first n
ones, or else the
empty general set, if this general set 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 general set 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 general set.
Tests whether a predicate holds for some element of this general set.
This method will use abort
signalling capabilities. This means
that splitters may send and read abort
signals.
a predicate used to test elements
true if p
holds for some element, false otherwise
Selects all elements of this general set which satisfy a predicate.
Selects all elements of this general set which satisfy a predicate.
the predicate used to test elements.
a new general set consisting of all elements of this general set that satisfy the given
predicate p
. Their order may not be preserved.
Selects all elements of this general set which do not satisfy a predicate.
Selects all elements of this general set which do not satisfy a predicate.
the predicate used to test elements.
a new general set consisting of all elements of this general set 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.
predicate used to test the elements
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 general set and using the elements of the resulting collections.
Builds a new collection by applying a function to all elements of this general set 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 general set. 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 a 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)
the element type of the returned collection.
the function to apply to each element.
a new general set resulting from applying the given collection-valued function
f
to each element of this general set and concatenating the results.
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 general set, going left to right.
Applies a binary operator to a start value and all elements of this general set, 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 general set,
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 general set.
Applies a binary operator to all elements of this general set and a start value, going right to left.
Applies a binary operator to all elements of this general set 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 general set,
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 general set.
Tests whether a predicate holds for all elements of this general set.
Tests whether a predicate holds for all elements of this general set.
This method will use abort
signalling capabilities. This means
that splitters may send and read abort
signals.
a predicate used to test elements
true if p
holds for all elements, false otherwise
Applies a function f
to all the elements of general set in a undefined order.
Applies a function f
to all the elements of general set in a undefined order.
the result type of the function applied to each element, which is always discarded
function applied to each element
Returns string formatted according to given format
string.
Returns string formatted according to given format
string.
Format strings are as for String.format
(@see java.lang.String.format).
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.
not specified by SLS as a member of AnyRef
Partitions this general set into a map of general sets according to some discriminator function.
Partitions this general set into a map of general sets 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 set.
the type of keys returned by the discriminator function.
the discriminator function.
A map from keys to general sets 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 general set 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 scala.Any.
the hash code value for this object.
Selects the first element of this general set.
Selects the first element of this general set.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the first element of this general set.
if the general set is empty.
Optionally selects the first element.
Optionally selects the first element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the first element of this general set if it is nonempty,
None
if it is empty.
Selects all elements except the last.
Selects all elements except the last.
Note: might return different results for different runs, unless the underlying collection type is ordered.
a general set consisting of all elements of this general set except the last one.
if the general set is empty.
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 general set is empty.
Tests whether the general set is empty.
true
if the general set 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 general set can be repeatedly traversed.
Tests whether this general set 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
Selects the last element.
Selects the last element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
The last element of this general set.
If the general set is empty.
Optionally selects the last element.
Optionally selects the last element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the last element of this general set$ if it is nonempty,
None
if it is empty.
[use case] Builds a new collection by applying a function to all elements of this general set.
Builds a new collection by applying a function to all elements of this general set.
the element type of the returned collection.
the function to apply to each element.
a new general set resulting from applying the given function
f
to each element of this general set and collecting the results.
[use case] Finds the largest element.
Finds the largest element.
the largest element of this general set.
[use case] Finds the smallest element.
Finds the smallest element.
the smallest element of this general set
Displays all elements of this general set in a string.
Displays all elements of this general set in a string.
a string representation of this general set. In the resulting string
the string representations (w.r.t. the method toString
)
of all elements of this general set follow each other without any
separator string.
Displays all elements of this general set in a string using a separator string.
Displays all elements of this general set in a string using a separator string.
the separator string.
a string representation of this general set. In the resulting string
the string representations (w.r.t. the method toString
)
of all elements of this general set are separated by the string sep
.
List(1, 2, 3).mkString("|") = "1|2|3"
Displays all elements of this general set in a string using start, end, and separator strings.
Displays all elements of this general set in a string using start, end, and separator strings.
the starting string.
the separator string.
the ending string.
a string representation of this general set. 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 general set 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.
Tests whether the general set is not empty.
Tests whether the general set is not empty.
true
if the general set 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.
not specified by SLS as a member of AnyRef
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.
not specified by SLS as a member of AnyRef
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 general set in two general sets according to a predicate.
Partitions this general set in two general sets according to a predicate.
the predicate on which to partition.
a pair of general sets: the first general set consists of all elements that
satisfy the predicate p
and the second general set consists of all elements
that don't. The relative order of the elements in the resulting general sets
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 in this general set 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 general set and as result type of product
.
Examples of such types are: Long
, Float
, Double
, BigInt
.
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.
if this general set is empty.
Optionally applies a binary operator to all elements of this general set, going left to right.
Optionally applies a binary operator to all elements of this general set, 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 general set 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 general set, going right to left.
Applies a binary operator to all elements of this general set, 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 general set,
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 general set.
if this general set is empty.
Optionally applies a binary operator to all elements of this general set, going right to left.
Optionally applies a binary operator to all elements of this general set, 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 general set 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 general set.
Checks if the other iterable collection contains the same elements in the same order as this general set.
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.
Note: The neutral element z
may be applied more than once.
neutral element for the operator op
the associative operator for the scan
a new general set containing the prefix scan of the elements in this general set
Produces a collection containing cumulative results of applying the operator going left to right.
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.
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 cumulative results of applying the operator going right to left.
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)
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.
the lowest index to include from this general set.
the lowest index to EXCLUDE from this general set.
a general set containing the elements greater than or equal to
index from
extending up to (but not including) index until
of this general set.
Splits this general set into a prefix/suffix pair according to a predicate.
Splits this general set 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 general set into two at a given position.
Splits this general set 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 general sets consisting of the first n
elements of this general set, and the other elements.
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 in this general set 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 general set and as result type of sum
.
Examples of such types are: Long
, Float
, Double
, BigInt
.
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 general set consisting of all elements of this general set except the first one.
if the general set is empty.
Selects first n elements.
Selects first n elements.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the number of elements to take from this general set.
a general set consisting only of the first n
elements of this general set,
or else the whole general set, 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 general set of elements that satisy the predicate pred
The task support object which is responsible for scheduling and load-balancing tasks to processors.
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.
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))
[use case] Converts this general set into another by copying all elements.
Converts this general set into another by copying all elements.
Note: will not terminate for infinite-sized collections.
The collection type to build.
a new collection containing all elements of this general set.
[use case] Converts this general set to an array.
Converts this general set to an array.
Note: will not terminate for infinite-sized collections.
an array containing all elements of this general set.
An ClassTag
must be available for the element type of this general set.
Converts this general set to a mutable buffer.
Converts this general set to a mutable buffer.
Note: will not terminate for infinite-sized collections.
a buffer containing all elements of this general set.
Converts this general set to an indexed sequence.
Converts this general set to an indexed sequence.
Note: will not terminate for infinite-sized collections.
an indexed sequence containing all elements of this general set.
Converts this general set to an iterable collection.
Converts this general set 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 general set.
Returns an Iterator over the elements in this general set.
Returns an Iterator over the elements in this general set. 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 general set.
Converts this general set to a list.
Converts this general set to a list.
Note: will not terminate for infinite-sized collections.
a list containing all elements of this general set.
[use case] Converts this general set to a map.
Converts this general set 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 of type immutable.Map[T, U]
containing all key/value pairs of type (T, U)
of this general set.
Converts this general set to a sequence.
Converts this general set 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 general set.
Converts this general set to a set.
Converts this general set to a set.
Note: will not terminate for infinite-sized collections.
a set containing all elements of this general set.
Converts this general set to a stream.
Converts this general set to a stream.
Note: will not terminate for infinite-sized collections.
a stream containing all elements of this general set.
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 general set to an unspecified Traversable.
Converts this general set 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 general set.
Converts this general set to a Vector.
Converts this general set to a Vector.
Note: will not terminate for infinite-sized collections.
a vector containing all elements of this general set.
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
.
[use case] Returns a general set formed from this general set and another iterable collection by combining corresponding elements in pairs.
Returns a general set formed from this general set 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 type of the second half of the returned pairs
The iterable providing the second half of each result pair
a new general set containing pairs consisting of
corresponding elements of this general set and that
. The length
of the returned collection is the minimum of the lengths of this general set and that
.
[use case] Returns a general set formed from this general set and another iterable collection by combining corresponding elements in pairs.
Returns a general set formed from this general set 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 type of the second half of the returned pairs
The iterable providing the second half of each result pair
the element to be used to fill up the result if this general set is shorter than that
.
the element to be used to fill up the result if that
is shorter than this general set.
a new general set containing pairs consisting of
corresponding elements of this general set and that
. The length
of the returned collection is the maximum of the lengths of this general set and that
.
If this general set is shorter than that
, thisElem
values are used to pad the result.
If that
is shorter than this general set, thatElem
values are used to pad the result.
[use case] Zips this general set with its indices.
Zips this general set with its indices.
Note: might return different results for different runs, unless the underlying collection type is ordered.
A new general set containing pairs consisting of all elements of this
general set paired with their index. Indices start at 0
.
List("a", "b", "c").zipWithIndex = List(("a", 0), ("b", 1), ("c", 2))
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
.
(parSetLike: StringAdd).+(other)
(parSetLike: StringAdd).self
(parSetLike: StringFormat).self
A syntactic sugar for out of order folding.
A syntactic sugar for out of order folding. See fold
.
Example:
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
(Since version 2.10.0) use fold instead
(parSetLike: ArrowAssoc[ParSetLike[T, Repr, Sequential]]).x
(Since version 2.10.0) Use leftOfArrow
instead
(parSetLike: Ensuring[ParSetLike[T, Repr, Sequential]]).x
(Since version 2.10.0) Use resultOfEnsuring
instead
A template trait for parallel sets. This trait is mixed in with concrete parallel sets to override the representation type.
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