Applies a binary operator to a start value and all elements of this collection or iterator, going left to right.
Applies a binary operator to a start value and all elements of this collection or iterator, going left to right.
Note: /:
is alternate syntax for foldLeft
; z /: xs
is the same as
xs foldLeft z
.
Examples:
Note that the folding function used to compute b is equivalent to that used to compute c.
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = (5 /: a)(_+_) b: Int = 15 scala> val c = (5 /: a)((x,y) => x + y) c: Int = 15
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
the result type of the binary operator.
the start value.
the binary operator.
the result of inserting op
between consecutive elements of this collection or iterator,
going left to right with the start value z
on the left:
op(...op(op(z, x_1), x_2), ..., x_n)
where x1, ..., xn
are the elements of this collection or iterator.
Applies a binary operator to all elements of this collection or iterator and a start value, going right to left.
Applies a binary operator to all elements of this collection or iterator and a start value, going right to left.
Note: :\
is alternate syntax for foldRight
; xs :\ z
is the same as
xs foldRight z
.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
Examples:
Note that the folding function used to compute b is equivalent to that used to compute c.
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = (a :\ 5)(_+_) b: Int = 15 scala> val c = (a :\ 5)((x,y) => x + y) c: Int = 15
the result type of the binary operator.
the start value
the binary operator
the result of inserting op
between consecutive elements of this collection or iterator,
going right to left with the start value z
on the right:
op(x_1, op(x_2, ... op(x_n, z)...))
where x1, ..., xn
are the elements of this collection or iterator.
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 an 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) and may be evaluated
more than once
an operator used to accumulate results within a partition
an associative operator used to combine results from different partitions
Counts the number of elements in the collection or iterator which satisfy a predicate.
Counts the number of elements in the collection or iterator which satisfy a predicate.
the predicate used to test elements.
the number of elements satisfying the predicate p
.
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 collection.
a general collection consisting of all elements of this general collection except the first n
ones, or else the
empty general collection, if this general collection has less than n
elements.
Drops longest prefix of elements that satisfy a predicate.
Drops longest prefix of elements that satisfy a predicate.
Note: might return different results for different runs, unless the underlying collection type is ordered.
The predicate used to test elements.
the longest suffix of this general collection whose first element
does not satisfy the predicate p
.
Selects all elements of this general collection which satisfy a predicate.
Selects all elements of this general collection which satisfy a predicate.
the predicate used to test elements.
a new general collection consisting of all elements of this general collection that satisfy the given
predicate p
. Their order may not be preserved.
Selects all elements of this general collection which do not satisfy a predicate.
Selects all elements of this general collection which do not satisfy a predicate.
the predicate used to test elements.
a new general collection consisting of all elements of this general collection that do not satisfy the given
predicate p
. Their order may not be preserved.
Finds the first element of the collection or iterator satisfying a predicate, if any.
Finds the first element of the collection or iterator satisfying a predicate, if any.
Note: may not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the predicate used to test elements.
an option value containing the first element in the collection or iterator
that satisfies p
, or None
if none exists.
Folds the elements of this collection or iterator using the specified associative binary operator.
Folds the elements of this collection or iterator using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
a type parameter for the binary operator, a supertype of A
.
a neutral element for the fold operation; may be added to the result
an arbitrary number of times, and must not change 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 collection or iterator, going left to right.
Applies a binary operator to a start value and all elements of this collection or iterator, 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 result type of the binary operator.
the start value.
the binary operator.
the result of inserting op
between consecutive elements of this collection or iterator,
going left to right with the start value z
on the left:
op(...op(z, x_1), x_2, ..., x_n)
where x1, ..., xn
are the elements of this collection or iterator.
Applies a binary operator to all elements of this collection or iterator and a start value, going right to left.
Applies a binary operator to all elements of this collection or iterator 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 result type of the binary operator.
the start value.
the binary operator.
the result of inserting op
between consecutive elements of this collection or iterator,
going right to left with the start value z
on the right:
op(x_1, op(x_2, ... op(x_n, z)...))
where x1, ..., xn
are the elements of this collection or iterator.
Returns the runtime class representation of the object.
Returns the runtime class representation of the object.
a class object corresponding to the runtime type of the receiver.
Partitions this general collection into a map of general collections according to some discriminator function.
Partitions this general collection into a map of general collections 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 collection.
the type of keys returned by the discriminator function.
the discriminator function.
A map from keys to general collections such that the following invariant holds:
(xs groupBy f)(k) = xs filter (x => f(x) == k)
That is, every key k
is bound to a general collection of those elements x
for which f(x)
equals k
.
Selects the first element of this general collection.
Selects the first element of this general collection.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the first element of this general collection.
NoSuchElementException
if the general collection 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 collection 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 collection consisting of all elements of this general collection except the last one.
UnsupportedOperationException
if the general collection is empty.
Tests whether the collection or iterator is empty.
Tests whether the collection or iterator is empty.
true
if the collection or iterator contains no elements, false
otherwise.
Tests whether this general collection can be repeatedly traversed.
Tests whether this general collection can be repeatedly traversed.
true
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 collection.
NoSuchElementException
If the general collection 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 collection$ if it is nonempty,
None
if it is empty.
Displays all elements of this collection or iterator in a string.
Displays all elements of this collection or iterator in a string.
a string representation of this collection or iterator. In the resulting string
the string representations (w.r.t. the method toString
)
of all elements of this collection or iterator follow each other without any
separator string.
Displays all elements of this collection or iterator in a string using a separator string.
Displays all elements of this collection or iterator in a string using a separator string.
the separator string.
a string representation of this collection or iterator. In the resulting string
the string representations (w.r.t. the method toString
)
of all elements of this collection or iterator are separated by the string sep
.
List(1, 2, 3).mkString("|") = "1|2|3"
Displays all elements of this collection or iterator in a string using start, end, and separator strings.
Displays all elements of this collection or iterator in a string using start, end, and separator strings.
the starting string.
the separator string.
the ending string.
a string representation of this collection or iterator. 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 collection or iterator are separated by
the string sep
.
List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
Tests whether the collection or iterator is not empty.
Tests whether the collection or iterator is not empty.
true
if the collection or iterator contains at least one element, false
otherwise.
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 collection in two general collections according to a predicate.
Partitions this general collection in two general collections according to a predicate.
the predicate on which to partition.
a pair of general collections: the first general collection consists of all elements that
satisfy the predicate p
and the second general collection consists of all elements
that don't. The relative order of the elements in the resulting general collections
may not be preserved.
Reduces the elements of this collection or iterator using the specified associative binary operator.
Reduces the elements of this collection or iterator using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
A type parameter for the binary operator, a supertype of A
.
A binary operator that must be associative.
The result of applying reduce operator op
between all the elements if the collection or iterator is nonempty.
UnsupportedOperationException
if this collection or iterator is empty.
Optionally applies a binary operator to all elements of this collection or iterator, going left to right.
Optionally applies a binary operator to all elements of this collection or iterator, 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 result type of the binary operator.
the binary operator.
an option value containing the result of reduceLeft(op)
if this collection or iterator is nonempty,
None
otherwise.
Reduces the elements of this collection or iterator, if any, using the specified associative binary operator.
Reduces the elements of this collection or iterator, if any, using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
A type parameter for the binary operator, a supertype of A
.
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 collection or iterator, going right to left.
Applies a binary operator to all elements of this collection or iterator, 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 result type of the binary operator.
the binary operator.
the result of inserting op
between consecutive elements of this collection or iterator,
going right to left:
op(x_1, op(x_2, ..., op(x_{n-1}, x_n)...))
where x1, ..., xn
are the elements of this collection or iterator.
UnsupportedOperationException
if this collection or iterator is empty.
Optionally applies a binary operator to all elements of this collection or iterator, going right to left.
Optionally applies a binary operator to all elements of this collection or iterator, 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 result type of the binary operator.
the binary operator.
an option value containing the result of reduceRight(op)
if this collection or iterator is nonempty,
None
otherwise.
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
combiner factory which provides a combiner
a new general collection containing the prefix scan of the elements in this general collection
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 type of the elements in the resulting collection
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 type of the elements in the resulting collection
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
(Changed in version 2.9.0) The behavior of scanRight
has changed. The previous behavior can be reproduced with scanRight.reverse.
The size of this general collection.
The size of this general collection.
Note: will not terminate for infinite-sized collections.
the number of elements in this general collection.
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 collection.
the lowest index to EXCLUDE from this general collection.
a general collection containing the elements greater than or equal to
index from
extending up to (but not including) index until
of this general collection.
Splits this general collection into a prefix/suffix pair according to a predicate.
Splits this general collection into a prefix/suffix pair according to a predicate.
Note: c span p
is equivalent to (but possibly more efficient than)
(c takeWhile p, c dropWhile p)
, provided the evaluation of the
predicate p
does not cause any side-effects.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the test predicate
a pair consisting of the longest prefix of this general collection whose
elements all satisfy p
, and the rest of this general collection.
Splits this general collection into two at a given position.
Splits this general collection into two at a given position.
Note: c splitAt n
is equivalent to (but possibly more efficient than)
(c take n, c drop n)
.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the position at which to split.
a pair of general collections consisting of the first n
elements of this general collection, 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 general collection. By default the string prefix is the
simple name of the collection class general collection.
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 collection consisting of all elements of this general collection except the first one.
UnsupportedOperationException
if the general collection 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 collection.
a general collection consisting only of the first n
elements of this general collection,
or else the whole general collection, if it has less than n
elements.
Takes longest prefix of elements that satisfy a predicate.
Takes longest prefix of elements that satisfy a predicate.
Note: might return different results for different runs, unless the underlying collection type is ordered.
The predicate used to test elements.
the longest prefix of this general collection whose elements all satisfy
the predicate p
.
Uses the contents of this collection or iterator to create a new mutable buffer.
Uses the contents of this collection or iterator to create a new mutable buffer.
Note: will not terminate for infinite-sized collections.
a buffer containing all elements of this collection or iterator.
Converts this collection or iterator to an indexed sequence.
Converts this collection or iterator to an indexed sequence.
Note: will not terminate for infinite-sized collections.
an indexed sequence containing all elements of this collection or iterator.
Converts this collection or iterator to an iterable collection.
Converts this collection or iterator 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 collection or iterator.
Returns an Iterator over the elements in this collection or iterator.
Returns an Iterator over the elements in this collection or iterator. 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 collection or iterator.
Converts this collection or iterator to a list.
Converts this collection or iterator to a list.
Note: will not terminate for infinite-sized collections.
a list containing all elements of this collection or iterator.
Converts this collection or iterator to a sequence.
Converts this collection or iterator 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 collection or iterator.
Converts this collection or iterator to a set.
Converts this collection or iterator to a set.
Note: will not terminate for infinite-sized collections.
a set containing all elements of this collection or iterator.
Converts this collection or iterator to a stream.
Converts this collection or iterator to a stream.
a stream containing all elements of this collection or iterator.
Converts this collection or iterator to an unspecified Traversable.
Converts this collection or iterator 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 collection or iterator.
Converts this collection or iterator to a Vector.
Converts this collection or iterator to a Vector.
Note: will not terminate for infinite-sized collections.
a vector containing all elements of this collection or 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 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 ==
[use case] Returns a new general collection containing the elements from the left hand operand followed by the elements from the right hand operand.
Returns a new general collection containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the general collection is the most specific superclass encompassing the element types of the two operands.
Example:
scala> val a = List(1) a: List[Int] = List(1) scala> val b = List(2) b: List[Int] = List(2) scala> val c = a ++ b c: List[Int] = List(1, 2) scala> val d = List('a') d: List[Char] = List(a) scala> val e = c ++ d e: List[AnyVal] = List(1, 2, a)
the element type of the returned collection.
the traversable to append.
a new general collection which contains all elements of this general collection
followed by all elements of that
.
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.
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.
ClassCastException
if the receiver object is not an instance of the erasure of type T0
.
[use case] Builds a new collection by applying a partial function to all elements of this general collection on which the function is defined.
Builds a new collection by applying a partial function to all elements of this general collection on which the function is defined.
the element type of the returned collection.
the partial function which filters and maps the general collection.
a new general collection 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.
[use case] Copies values of this general collection to an array.
Copies values of this general collection to an array.
Fills the given array xs
with values of this general collection, beginning at index start
.
Copying will stop once either the end of the current general collection 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 collection to an array.
Copies values of this general collection to an array.
Fills the given array xs
with values of this general collection.
Copying will stop once either the end of the current general collection is reached,
or the end of the array is reached.
Note: will not terminate for infinite-sized collections.
the array to fill.
Compares the receiver object (this
) with the argument object (that
) for equivalence.
Compares the receiver object (this
) with the argument object (that
) for equivalence.
Any implementation of this method should be an equivalence relation:
x
of type Any
, x.equals(x)
should return true
.x
and y
of type Any
, x.equals(y)
should return true
if and
only if y.equals(x)
returns true
.x
, y
, and z
of type AnyRef
if x.equals(y)
returns true
and
y.equals(z)
returns true
, then x.equals(z)
should return true
. If you override this method, you should verify that your implementation remains an equivalence relation.
Additionally, when overriding this method it is usually necessary to override hashCode
to ensure that
objects which are "equal" (o1.equals(o2)
returns true
) hash to the same scala.Int.
(o1.hashCode.equals(o2.hashCode)
).
true
if the receiver object is equivalent to the argument; false
otherwise.
[use case] Builds a new collection by applying a function to all elements of this general collection and using the elements of the resulting collections.
Builds a new collection by applying a function to all elements of this general collection 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 collection. This might cause unexpected results sometimes. For example:
// lettersOf will return a Seq[Char] of likely repeated letters, instead of a Set def lettersOf(words: Seq[String]) = words flatMap (word => word.toSet) // lettersOf will return a Set[Char], not a Seq def lettersOf(words: Seq[String]) = words.toSet flatMap (word => word.toSeq) // xs will be an Iterable[Int] val xs = Map("a" -> List(11,111), "b" -> List(22,222)).flatMap(_._2) // ys will be a Map[Int, Int] val ys = Map("a" -> List(1 -> 11,1 -> 111), "b" -> List(2 -> 22,2 -> 222)).flatMap(_._2)
the element type of the returned collection.
the function to apply to each element.
a new general collection resulting from applying the given collection-valued function
f
to each element of this general collection and concatenating the results.
[use case] Applies a function f
to all elements of this general collection.
Applies a function f
to all elements of this general collection.
the function that is applied for its side-effect to every element.
The result of function f
is discarded.
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).
Calculate a hash code value for the object.
Calculate a hash code value for the object.
The default hashing algorithm is platform dependent.
Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)
) yet
not be equal (o1.equals(o2)
returns false
). A degenerate implementation could always return 0
.
However, it is required that if two objects are equal (o1.equals(o2)
returns true
) that they have
identical hash codes (o1.hashCode.equals(o2.hashCode)
). Therefore, when overriding this method, be sure
to verify that the behavior is consistent with the equals
method.
the hash code value for this object.
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.
[use case] Builds a new collection by applying a function to all elements of this general collection.
Builds a new collection by applying a function to all elements of this general collection.
the element type of the returned collection.
the function to apply to each element.
a new general collection resulting from applying the given function
f
to each element of this general collection and collecting the results.
[use case] Finds the largest element.
Finds the largest element.
the largest element of this general collection.
[use case] Finds the first element which yields the largest value measured by function f.
Finds the first element which yields the largest value measured by function f.
The result type of the function f.
The measuring function.
the first element of this general collection with the largest value measured by function f.
[use case] Finds the smallest element.
Finds the smallest element.
the smallest element of this general collection
[use case] Finds the first element which yields the smallest value measured by function f.
Finds the first element which yields the smallest value measured by function f.
The result type of the function f.
The measuring function.
the first element of this general collection with the smallest value measured by function f.
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
[use case] Multiplies up the elements of this collection.
Multiplies up the elements of this collection.
the product of all elements in this general collection 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 collection and as result type of product
.
Examples of such types are: Long
, Float
, Double
, BigInt
.
[use case] Sums up the elements of this collection.
Sums up the elements of this collection.
the sum of all elements in this general collection 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 collection and as result type of sum
.
Examples of such types are: Long
, Float
, Double
, BigInt
.
[use case] Converts this general collection into another by copying all elements.
Converts this general collection 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 collection.
[use case] Converts this general collection to an array.
Converts this general collection to an array.
Note: will not terminate for infinite-sized collections.
an array containing all elements of this general collection.
An ClassTag
must be available for the element type of this general collection.
[use case] Converts this general collection to a map.
Converts this general collection 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 collection.
Returns a string representation of the object.
Returns a string representation of the object.
The default representation is platform dependent.
a string representation of the object.
A template trait for all traversable collections upon which operations may be implemented in parallel.