A template trait for sequences of type ParSeq[T], representing
parallel sequences with element type T.
Parallel sequences inherit the Seq trait. Their indexing and length computations
are defined to be efficient. Like their sequential counterparts
they always have a defined order of elements. This means they will produce resulting
parallel sequences in the same way sequential sequences do. However, the order
in which they perform bulk operations on elements to produce results is not defined and is generally
nondeterministic. If the higher-order functions given to them produce no sideeffects,
then this won't be noticeable.
This trait defines a new, more general split operation and reimplements the split
operation of ParallelIterable trait using the new split operation.
the type of the elements contained in this collection
the type of the actual collection containing the elements
the type of the sequential version of this parallel collection
2.9
Standard accessor task that iterates over the elements of the collection.
Used to iterate elements using indices
Performs two tasks in parallel, and waits for both to finish.
An iterator that can be split into arbitrary subsets of iterators.
The type implementing this traversable
Sequentially performs one task after another.
A stackable modification that ensures signal contexts get passed along the iterators.
A class supporting filtered operations.
o != arg0 is the same as !(o == (arg0)).
o != arg0 is the same as !(o == (arg0)).
the object to compare against this object for dis-equality.
false if the receiver object is equivalent to the argument; true otherwise.
[use case] Concatenates this sequence with the elements of a traversable collection.
Concatenates this sequence with the elements of a traversable collection.
the element type of the returned collection.
the traversable to append.
a new sequence which contains all elements of this sequence
followed by all elements of that.
Concatenates this sequence with the elements of a traversable collection.
Concatenates this sequence 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 the new element type B.
a new collection of type That which contains all elements
of this sequence followed by all elements of that.
This overload exists because: for the implementation of ++: we should reuse that of ++ because many collections override it with more efficient versions.
This overload exists because: for the implementation of ++: we should reuse that of ++ because many collections override it with more efficient versions. Since TraversableOnce has no '++' method, we have to implement that directly, but Traversable and down can use the overload.
[use case] Concatenates this sequence with the elements of a traversable collection.
Concatenates this sequence with the elements of a traversable collection. It differs from ++ in that the right operand determines the type of the resulting collection rather than the left one.
the element type of the returned collection.
the traversable to append.
a new sequence which contains all elements of this sequence
followed by all elements of that.
Concatenates this sequence with the elements of a traversable collection.
Concatenates this sequence with the elements of a traversable collection. It differs from ++ in that the right operand determines the type of the resulting collection rather than the left one.
the element type of the returned 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 the new element type B.
a new collection of type That which contains all elements
of this sequence followed by all elements of that.
[use case] Prepends an element to this sequence
Prepends an element to this sequence
the prepended element
a new sequence consisting of elem followed
by all elements of this sequence.
Prepends an element to this sequence
Prepends an element to this sequence
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 prepended element
an implicit value of class CanBuildFrom which determines the
result class That from the current representation type Repr
and the new element type B.
a new collection of type That consisting of elem followed
by all elements of this sequence.
Applies a binary operator to a start value and all elements of this sequence, going left to right.
Applies a binary operator to a start value and all elements of this sequence, 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.
the result type of the binary operator.
the start value.
the binary operator.
the result of inserting op between consecutive elements of this sequence,
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 sequence.
[use case] Appends an element to this sequence
Appends an element to this sequence
Note: will not terminate for infinite-sized collections.
the appended element
a new sequence consisting of
all elements of this sequence followed by elem.
Appends an element to this sequence
Appends an element to this sequence
Note: will not terminate for infinite-sized collections.
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 appended element
an implicit value of class CanBuildFrom which determines the
result class That from the current representation type Repr
and the new element type B.
a new collection of type That consisting of
all elements of this sequence followed by elem.
Applies a binary operator to all elements of this sequence and a start value, going right to left.
Applies a binary operator to all elements of this sequence 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.
the result type of the binary operator.
the start value
the binary operator
the result of inserting op between consecutive elements of this sequence,
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 sequence.
o == arg0 is the same as if (o eq null) arg0 eq null else o.equals(arg0).
o == arg0 is the same as if (o eq null) arg0 eq null else o.equals(arg0).
the object to compare against this object for equality.
true if the receiver object is equivalent to the argument; false otherwise.
o == arg0 is the same as o.equals(arg0).
o == arg0 is the same as o.equals(arg0).
the object to compare against this object for equality.
true if the receiver object is equivalent to the argument; false otherwise.
Appends all elements of this sequence to a string builder.
Appends all elements of this sequence to a string builder.
The written text consists of the string representations (w.r.t. the method
toString) of all elements of this sequence without any separator string.
the string builder to which elements are appended.
the string builder b to which elements were appended.
Appends all elements of this sequence to a string builder using a separator string.
Appends all elements of this sequence to a string builder using a separator
string. The written text consists of the string representations (w.r.t.
the method toString) of all elements of this sequence, separated by the
string sep.
the string builder to which elements are appended.
the separator string.
the string builder b to which elements were appended.
Appends all elements of this sequence to a string builder using start, end, and separator strings.
Appends all elements of this sequence to a string builder using start, end,
and separator strings.
The written text 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 sequence are separated by the string sep.
the string builder to which elements are appended.
the starting string.
the separator string.
the ending string.
the string builder b to which elements were appended.
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
Selects an element by its index in the sequence.
Selects an element by its index in the sequence.
The index to select.
the element of this sequence at index idx, where 0 indicates the first element.
This method is used to cast the receiver object to be of type T0.
This method is used to 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 typed.
the receiver object.
Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.
Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.
The object with which this sequence should be compared
true, if this sequence can possibly equal that, false otherwise. The test
takes into consideration only the run-time types of objects but ignores their elements.
This method creates and returns a copy of the receiver object.
[use case] Builds a new collection by applying a partial function to all elements of this sequence on which the function is defined.
Builds a new collection by applying a partial function to all elements of this sequence on which the function is defined.
the element type of the returned collection.
the partial function which filters and maps the sequence.
a new sequence 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.
Builds a new collection by applying a partial function to all elements of this sequence on which the function is defined.
Builds a new collection by applying a partial function to all elements of this sequence 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 sequence.
an implicit value of class CanBuildFrom which determines the
result class That from the current representation type Repr
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.
Finds the first element of the sequence for which the given partial function is defined, and applies the partial function to it.
Finds the first element of the sequence for which the given partial function is defined, and applies the partial function to it.
Note: may not terminate for infinite-sized collections.
the partial function
an option value containing pf applied to the first
value for which it is defined, or None if none exists.
Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)
Iterates over combinations.
Iterates over combinations.
An Iterator which traverses the possible n-element combinations of this sequence.
"abbbc".combinations(2) = Iterator(ab, ac, bb, bc)
Tests whether this sequence contains a given value as an element.
Tests whether this sequence contains a given value as an element.
Note: may not terminate for infinite-sized collections.
the element to test.
true if this sequence has an element that is
is equal (wrt ==) to elem, false otherwise.
Tests whether this sequence contains a given sequence as a slice.
Tests whether this sequence contains a given sequence as a slice.
Note: may not terminate for infinite-sized collections.
the sequence to test
true if this sequence contains a slice with the same elements
as that, otherwise false.
[use case] Copies elements of this sequence to an array.
Copies elements of this sequence to an array.
Fills the given array xs with at most len elements of
this sequence, starting at position start.
Copying will stop once either the end of the current sequence is reached,
or the end of the array is reached, or len elements have been copied.
the array to fill.
the starting index.
the maximal number of elements to copy.
Copies elements of this sequence to an array.
Copies elements of this sequence to an array.
Fills the given array xs with at most len elements of
this sequence, starting at position start.
Copying will stop once either the end of the current sequence is reached,
or the end of the array is reached, or len elements have been copied.
Note: will not terminate for infinite-sized collections.
the array to fill.
the starting index.
the maximal number of elements to copy.
[use case] Copies values of this sequence to an array.
Copies values of this sequence to an array.
Fills the given array xs with values of this sequence.
Copying will stop once either the end of the current sequence is reached,
or the end of the array is reached.
the array to fill.
Copies values of this sequence to an array.
Copies values of this sequence to an array.
Fills the given array xs with values of this sequence.
Copying will stop once either the end of the current sequence is reached,
or the end of the array is reached.
Note: will not terminate for infinite-sized collections.
the type of the elements of the array.
the array to fill.
[use case] Copies values of this sequence to an array.
Copies values of this sequence to an array.
Fills the given array xs with values of this sequence, after skipping start values.
Copying will stop once either the end of the current sequence is reached,
or the end of the array is reached.
the array to fill.
the starting index.
Copies values of this sequence to an array.
Copies values of this sequence to an array.
Fills the given array xs with values of this sequence, after skipping start values.
Copying will stop once either the end of the current sequence is reached,
or the end of the array is reached.
Note: will not terminate for infinite-sized collections.
the type of the elements of the array.
the array to fill.
the starting index.
Copies all elements of this sequence to a buffer.
Copies all elements of this sequence to a buffer.
Note: will not terminate for infinite-sized collections.
The buffer to which elements are copied.
Tests whether every element of this sequence relates to the corresponding element of another parallel sequence by satisfying a test predicate.
Tests whether every element of this sequence relates to the corresponding element of another parallel sequence by satisfying a test predicate.
This method will use abort signalling capabilities. This means
that splitters may send and read abort signals.
the type of the elements of that
the other parallel sequence
the test predicate, which relates elements from both sequences
true if both parallel sequences have the same length and
p(x, y) is true for all corresponding elements x of this sequence
and y of that, otherwise false
Counts the number of elements in the sequence which satisfy a predicate.
Counts the number of elements in the sequence which satisfy a predicate.
the predicate used to test elements.
the number of elements satisfying the predicate p.
[use case] Computes the multiset difference between this sequence and another sequence.
Computes the multiset difference between this sequence and another sequence.
Note: will not terminate for infinite-sized collections.
the sequence of elements to remove
a new sequence which contains all elements of this sequence
except some of occurrences of elements that also appear in that.
If an element value x appears
n times in that, then the first n occurrences of x will not form
part of the result, but any following occurrences will.
Computes the multiset difference between this sequence and another sequence.
Computes the multiset difference between this sequence and another sequence.
Note: will not terminate for infinite-sized collections.
the element type of the returned sequence.
the sequence of elements to remove
a new collection of type That which contains all elements of this sequence
except some of occurrences of elements that also appear in that.
If an element value x appears
n times in that, then the first n occurrences of x will not form
part of the result, but any following occurrences will.
Builds a new sequence from this sequence without any duplicate elements.
Builds a new sequence from this sequence without any duplicate elements.
Note: will not terminate for infinite-sized collections.
A new sequence which contains the first occurrence of every element of this sequence.
Selects all elements except first n ones.
Selects all elements except first n ones.
the number of elements to drop from this sequence.
a sequence consisting of all elements of this sequence except the first n ones, or else the
empty sequence, if this sequence has less than n elements.
Selects all elements except last n ones.
Selects all elements except last n ones.
The number of elements to take
a sequence consisting of all elements of this sequence except the last n ones, or else the
empty sequence, if this sequence 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 sequence that satisfy the predicate pred
use iterator' instead
Tests whether this sequence ends with the given parallel sequence
Tests whether this sequence ends with the given parallel sequence
This method will use abort signalling capabilities. This means
that splitters may send and read abort signals.
the type of the elements of that sequence
the sequence to test
true if this sequence has that as a suffix, false otherwise
This method is used to test whether the argument (arg0) is a reference to the
receiver object (this).
This method is used to test whether the argument (arg0) is a reference to the
receiver object (this).
The eq method implements an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation] on
non-null instances of AnyRef:
* It is reflexive: for any non-null instance x of type AnyRef, x.eq(x) returns true.
* It is symmetric: for any non-null instances x and y of type AnyRef, x.eq(y) returns true if and
only if y.eq(x) returns true.
* It is transitive: for any non-null instances x, y, and z of type AnyRef if x.eq(y) returns true
and y.eq(z) returns true, then x.eq(z) returns true.
Additionally, the eq method has three other properties.
* It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of
x.eq(y) consistently returns true or consistently returns false.
* For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false.
* null.eq(null) returns true.
When overriding the equals or hashCode methods, it is important to ensure that their behavior is
consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they
should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).
the object to compare against this object for reference equality.
true if the argument is a reference to the receiver object; false otherwise.
The equals method for arbitrary sequences.
Tests whether every element of this sequence relates to the corresponding element of another sequence by satisfying a test predicate.
Tests whether every element of this sequence relates to the corresponding element of another sequence by satisfying a test predicate.
the type of the elements of that
the other sequence
true if both sequences have the same length and
p(x, y) is true for all corresponding elements x of this sequence
and y of that, otherwise false.
use corresponds instead
Tests whether a predicate holds for some element of this sequence.
Tests whether a predicate holds for some element of this sequence.
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 sequence which satisfy a predicate.
Selects all elements of this sequence which satisfy a predicate.
a new sequence consisting of all elements of this sequence that satisfy the given
predicate p. The order of the elements is preserved.
Selects all elements of this sequence which do not satisfy a predicate.
Selects all elements of this sequence which do not satisfy a predicate.
a new sequence consisting of all elements of this sequence that do not satisfy the given
predicate p. The order of the elements is preserved.
This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.
This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.
The details of when and if the finalize method are 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
Returns index of the first element satisfying a predicate, or -1.
Returns index of the first element satisfying a predicate, or -1.
Returns index of the last element satisfying a predicate, or -1.
Returns index of the last element satisfying a predicate, or -1.
use lastIndexWhere instead
use head' instead
None if iterable is empty.
None if iterable is empty.
use headOption' instead
[use case] Builds a new collection by applying a function to all elements of this sequence and concatenating the results.
Builds a new collection by applying a function to all elements of this sequence and concatenating the results.
the element type of the returned collection.
the function to apply to each element.
a new sequence resulting from applying the given collection-valued function
f to each element of this sequence and concatenating the results.
Builds a new collection by applying a function to all elements of this sequence and concatenating the results.
Builds a new collection by applying a function to all elements of this sequence 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 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 sequence 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 sequence, going left to right.
Applies a binary operator to a start value and all elements of this sequence, going left to right.
Note: will not terminate for infinite-sized collections.
the start value.
the binary operator.
the result of inserting op between consecutive elements of this sequence,
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 sequence.
Applies a binary operator to all elements of this sequence and a start value, going right to left.
Applies a binary operator to all elements of this sequence and a start value, going right to left.
Note: will not terminate for infinite-sized collections.
the start value.
the binary operator.
the result of inserting op between consecutive elements of this sequence,
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 sequence.
Tests whether a predicate holds for all elements of this sequence.
Tests whether a predicate holds for all elements of this sequence.
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 sequence in a sequential order.
Applies a function f to all the elements of sequence in a sequential order.
the result type of the function applied to each element, which is always discarded
function applied to each element
Returns a representation that corresponds to the dynamic class of the receiver object.
Returns 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 sequence into a map of sequences according to some discriminator function.
Partitions this sequence into a map of sequences 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 sequence.
the type of keys returned by the discriminator function.
the discriminator function.
A map from keys to sequences 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 sequence of those elements x
for which f(x) equals k.
Partitions elements in fixed size sequences.
Partitions elements in fixed size sequences.
the number of elements per group
An iterator producing sequences of size size, except the
last will be truncated if the elements don't divide evenly.
Iterator#grouped
Tests whether this sequence is known to have a finite size.
Tests whether this sequence is known to have a finite size.
All strict collections are known to have finite size. For a non-strict collection
such as Stream, the predicate returns true if all elements have been computed.
It returns false if the stream is not yet evaluated to the end.
Note: many collection methods will not work on collections of infinite sizes.
true if this collection is known to have finite size, false otherwise.
Hashcodes for Seq produce a value from the hashcodes of all the elements of the sequence.
Hashcodes for Seq produce a value from the hashcodes of all the elements of the sequence.@return the hash code value for the object. */
Selects the first element of this sequence.
Selects the first element of this sequence.
the first element of this sequence.
Optionally selects the first element.
Optionally selects the first element.
the first element of this sequence if it is nonempty, None if it is empty.
[use case] Finds index of first occurrence of some value in this sequence after or at some start index.
Finds index of first occurrence of some value in this sequence after or at some start index.
the element value to search for.
the start index
the index >= from of the first element of this sequence that is equal (wrt ==)
to elem, or -1, if none exists.
Finds index of first occurrence of some value in this sequence after or at some start index.
Finds index of first occurrence of some value in this sequence after or at some start index.
Note: may not terminate for infinite-sized collections.
the element value to search for.
the start index
the index >= from of the first element of this sequence that is equal (wrt ==)
to elem, or -1, if none exists.
[use case] Finds index of first occurrence of some value in this sequence.
Finds index of first occurrence of some value in this sequence.
the element value to search for.
the index of the first element of this sequence that is equal (wrt ==)
to elem, or -1, if none exists.
Finds index of first occurrence of some value in this sequence.
Finds index of first occurrence of some value in this sequence.
Note: may not terminate for infinite-sized collections.
the element value to search for.
the index of the first element of this sequence that is equal (wrt ==)
to elem, or -1, if none exists.
Finds first index after or at a start index where this sequence contains a given sequence as a slice.
Finds first index after or at a start index where this sequence contains a given sequence as a slice.
Note: may not terminate for infinite-sized collections.
the sequence to test
the start index
the first index >= from such that the elements of this sequence starting at this index
match the elements of sequence that, or -1 of no such subsequence exists.
Finds first index where this sequence contains a given sequence as a slice.
Finds first index where this sequence contains a given sequence as a slice.
Note: may not terminate for infinite-sized collections.
the sequence to test
the first index such that the elements of this sequence starting at this index
match the elements of sequence that, or -1 of no such subsequence exists.
Finds index of first element satisfying some predicate.
Finds index of first element satisfying some predicate.
Note: may not terminate for infinite-sized collections.
the predicate used to test elements.
the index of the first element of this sequence that satisfies the predicate p,
or -1, if none exists.
Finds the first element satisfying some predicate.
Finds the first element satisfying some predicate.
This method will use indexFlag signalling capabilities. This means
that splitters may set and read the indexFlag state.
The index flag is initially set to maximum integer value.
the predicate used to test the elements
the starting offset for the search
the index >= from of the first element of this sequence that satisfies the predicate p,
or -1, if none exists
Produces the range of all indices of this sequence.
Produces the range of all indices of this sequence.
a Range value from 0 to one less than the length of this sequence.
Selects all elements except the last.
Selects all elements except the last.
a sequence consisting of all elements of this sequence except the last one.
Iterates over the inits of this sequence.
Iterates over the inits of this sequence. The first value will be this
sequence and the final one will be an empty sequence, with the intervening
values the results of successive applications of init.
an iterator over all the inits of this sequence
List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)
[use case] Computes the multiset intersection between this sequence and another sequence.
Computes the multiset intersection between this sequence and another sequence.
Note: may not terminate for infinite-sized collections.
the sequence of elements to intersect with.
a new sequence which contains all elements of this sequence
which also appear in that.
If an element value x appears
n times in that, then the first n occurrences of x will be retained
in the result, but any following occurrences will be omitted.
Computes the multiset intersection between this sequence and another sequence.
Computes the multiset intersection between this sequence and another sequence.
Note: may not terminate for infinite-sized collections.
the element type of the returned sequence.
the sequence of elements to intersect with.
a new collection of type That which contains all elements of this sequence
which also appear in that.
If an element value x appears
n times in that, then the first n occurrences of x will be retained
in the result, but any following occurrences will be omitted.
Tests whether this sequence contains given index.
Tests whether this sequence contains given index.
The implementations of methods apply and isDefinedAt turn a Seq[A] into
a PartialFunction[Int, A].
the index to test
true if this sequence contains an element at position idx, false otherwise.
Tests whether this sequence is empty.
Tests whether this sequence is empty.
true if the sequence contain no elements, false otherwise.
This method is used to test whether the dynamic type of the receiver object is T0.
This method is used to test whether the dynamic type of the receiver object is T0.
Note that the test 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 requested typed.
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 sequence can be repeatedly traversed.
Tests whether this sequence 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 parallelIterator method.
a split iterator
Selects the last element.
Selects the last element.
The last element of this sequence.
[use case] Finds index of last occurrence of some value in this sequence before or at a given end index.
Finds index of last occurrence of some value in this sequence before or at a given end index.
the element value to search for.
the end index.
the index <= end of the last element of this sequence that is equal (wrt ==)
to elem, or -1, if none exists.
Finds index of last occurrence of some value in this sequence before or at a given end index.
Finds index of last occurrence of some value in this sequence before or at a given end index.
the type of the element elem.
the element value to search for.
the end index.
the index <= end of the last element of this sequence that is equal (wrt ==)
to elem, or -1, if none exists.
[use case] Finds index of last occurrence of some value in this sequence.
Finds index of last occurrence of some value in this sequence.
the element value to search for.
the index of the last element of this sequence that is equal (wrt ==)
to elem, or -1, if none exists.
Finds index of last occurrence of some value in this sequence.
Finds index of last occurrence of some value in this sequence.
Note: will not terminate for infinite-sized collections.
the type of the element elem.
the element value to search for.
the index of the last element of this sequence that is equal (wrt ==)
to elem, or -1, if none exists.
Finds last index before or at a given end index where this sequence contains a given sequence as a slice.
Finds last index before or at a given end index where this sequence contains a given sequence as a slice.
the sequence to test
the end index
the last index <= end such that the elements of this sequence starting at this index
match the elements of sequence that, or -1 of no such subsequence exists.
Finds last index where this sequence contains a given sequence as a slice.
Finds last index where this sequence contains a given sequence as a slice.
Note: will not terminate for infinite-sized collections.
the sequence to test
the last index such that the elements of this sequence starting a this index
match the elements of sequence that, or -1 of no such subsequence exists.
Finds the last element satisfying some predicate.
Finds the last element satisfying some predicate.
This method will use indexFlag signalling capabilities. This means
that splitters may set and read the indexFlag state.
The index flag is initially set to minimum integer value.
the predicate used to test the elements
the maximum offset for the search
the index <= end of the first element of this sequence that satisfies the predicate p,
or -1, if none exists
Finds index of last element satisfying some predicate.
Finds index of last element satisfying some predicate.
Note: will not terminate for infinite-sized collections.
the predicate used to test elements.
the index of the last element of this sequence that satisfies the predicate p,
or -1, if none exists.
Optionally selects the last element.
Optionally selects the last element.
the last element of this sequence$ if it is nonempty, None if it is empty.
The length of the sequence.
The length of the sequence.
Note: will not terminate for infinite-sized collections.
Note: xs.length and xs.size yield the same result.
the number of elements in this sequence.
Compares the length of this sequence to a test value.
Compares the length of this sequence to a test value.
the test value that gets compared with the length.
A value x where
x < 0 if this.length < len
x == 0 if this.length == len
x > 0 if this.length > len
The method as implemented here does not call length directly; its running time
is O(length min len) instead of O(length). The method should be overwritten
if computing length is cheap.
[use case] Builds a new collection by applying a function to all elements of this sequence.
Builds a new collection by applying a function to all elements of this sequence.
the element type of the returned collection.
the function to apply to each element.
a new sequence resulting from applying the given function
f to each element of this sequence and collecting the results.
Builds a new collection by applying a function to all elements of this sequence.
Builds a new collection by applying a function to all elements of this sequence.
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 the new element type B.
a new collection of type That resulting from applying the given function
f to each element of this sequence and collecting the results.
[use case] Finds the largest element.
Finds the largest element.
the largest element of this sequence.
Finds the largest element.
Finds the largest element.
the largest element of this sequence with respect to the ordering cmp.
[use case] Finds the smallest element.
Finds the smallest element.
the smallest element of this sequence
Finds the smallest element.
Finds the smallest element.
the smallest element of this sequence with respect to the ordering cmp.
Displays all elements of this sequence in a string.
Displays all elements of this sequence in a string.
a string representation of this sequence. In the resulting string
the string representations (w.r.t. the method toString)
of all elements of this sequence follow each other without any
separator string.
Displays all elements of this sequence in a string using a separator string.
Displays all elements of this sequence in a string using a separator string.
the separator string.
a string representation of this sequence. In the resulting string
the string representations (w.r.t. the method toString)
of all elements of this sequence are separated by the string sep.
List(1, 2, 3).mkString("|") = "1|2|3"
Displays all elements of this sequence in a string using start, end, and separator strings.
Displays all elements of this sequence in a string using start, end, and separator strings.
the starting string.
the separator string.
the ending string.
a string representation of this sequence. 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 sequence are separated by
the string sep.
List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
o.ne(arg0) is the same as !(o.eq(arg0)).
o.ne(arg0) is the same as !(o.eq(arg0)).
the object to compare against this object for reference dis-equality.
false if the argument is not a reference to the receiver object; true otherwise.
The newBuilder operation returns a parallel builder assigned to this collection's fork/join pool.
The newBuilder operation returns a parallel builder assigned to this collection's fork/join pool.
This method forwards the call to newCombiner.
Tests whether the sequence is not empty.
Tests whether the sequence is not empty.
true if the sequence 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.
[use case] Appends an element value to this sequence until a given target length is reached.
Appends an element value to this sequence until a given target length is reached.
the target length
the padding value
a new sequence consisting of
all elements of this sequence followed by the minimal number of occurrences of elem so
that the resulting sequence has a length of at least len.
Appends an element value to this sequence until a given target length is reached.
Appends an element value to this sequence until a given target length is reached.
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 target length
the padding value
an implicit value of class CanBuildFrom which determines the
result class That from the current representation type Repr
and the new element type B.
a new collection of type That consisting of
all elements of this sequence followed by the minimal number of occurrences of elem so
that the resulting collection has a length of at least len.
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
A more refined version of the iterator found in the ParallelIterable trait,
this iterator can be split into arbitrary subsets of iterators.
A more refined version of the iterator found in the ParallelIterable trait,
this iterator can be split into arbitrary subsets of iterators.
an iterator that can be split into subsets of precise size
Partitions this sequence in two sequences according to a predicate.
Partitions this sequence in two sequences according to a predicate.
a pair of sequences: the first sequence consists of all elements that
satisfy the predicate p and the second sequence consists of all elements
that don't. The relative order of the elements in the resulting sequences
is the same as in the original sequence.
[use case] Produces a new sequence where a slice of elements in this sequence is replaced by another sequence.
Produces a new sequence where a slice of elements in this sequence is replaced by another sequence.
the index of the first replaced element
the number of elements to drop in the original sequence
a new sequence consisting of all elements of this sequence
except that replaced elements starting from from are replaced
by patch.
Produces a new sequence where a slice of elements in this sequence is replaced by another sequence.
Produces a new sequence where a slice of elements in this sequence is replaced by another sequence.
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 index of the first replaced element
the replacement sequence
the number of elements to drop in the original sequence
an implicit value of class CanBuildFrom which determines the
result class That from the current representation type Repr
and the new element type B.
a new sequence consisting of all elements of this sequence
except that replaced elements starting from from are replaced
by patch.
Iterates over distinct permutations.
Iterates over distinct permutations.
An Iterator which traverses the distinct permutations of this sequence.
"abb".permutations = Iterator(abb, bab, bba)
Returns the length of the longest prefix whose elements all satisfy some predicate.
Returns the length of the longest prefix whose elements all satisfy some predicate.
Note: may not terminate for infinite-sized collections.
the predicate used to test elements.
the length of the longest prefix of this sequence
such that every element of the segment satisfies the predicate p.
[use case] Multiplies up the elements of this collection.
Multiplies up the elements of this collection.
the product of all elements in this sequence 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 sequence and as result type of product.
Examples of such types are: Long, Float, Double, BigInt.
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 sequence with respect to the * operator in num.
returns a projection that can be used to call non-strict filter,
map, and flatMap methods that build projections
of the collection.
returns a projection that can be used to call non-strict filter,
map, and flatMap methods that build projections
of the collection.
use view' instead
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 the operations on elements are performed 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.
Applies a binary operator to all elements of this sequence, going left to right.
Applies a binary operator to all elements of this sequence, going left to right.
Note: will not terminate for infinite-sized collections.
the binary operator.
the result of inserting op between consecutive elements of this sequence,
going left to right:
op(...(op(x,,1,,, x,,2,,), ... ) , x,,n,,)
where x,,1,,, ..., x,,n,, are the elements of this sequence.
Optionally applies a binary operator to all elements of this sequence, going left to right.
Optionally applies a binary operator to all elements of this sequence, going left to right.
Note: will not terminate for infinite-sized collections.
the result type of the binary operator.
the binary operator.
an option value containing the result of reduceLeft(op) is this sequence 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 the operations on elements are performed 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 sequence, going right to left.
Applies a binary operator to all elements of this sequence, going right to left.
Note: will not terminate for infinite-sized collections.
the binary operator.
the result of inserting op between consecutive elements of this sequence,
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 sequence.
Optionally applies a binary operator to all elements of this sequence, going right to left.
Optionally applies a binary operator to all elements of this sequence, going right to left.
Note: will not terminate for infinite-sized collections.
the result type of the binary operator.
the binary operator.
an option value containing the result of reduceRight(op) is this sequence is nonempty,
None otherwise.
The collection of type sequence underlying this TraversableLike object.
The collection of type sequence underlying this TraversableLike object.
By default this is implemented as the TraversableLike object itself,
but this can be overridden.
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.
Returns new sequence wih elements in reversed order.
Returns new sequence wih elements in reversed order.
Note: will not terminate for infinite-sized collections.
A new sequence with all elements of this sequence in reversed order.
An iterator yielding elements in reversed order.
An iterator yielding elements in reversed order.
Note: will not terminate for infinite-sized collections.
Note: xs.reverseIterator is the same as xs.reverse.iterator but might be more efficient.
an iterator yielding the elements of this sequence in reversed order
[use case] Builds a new collection by applying a function to all elements of this sequence and collecting the results in reversed order.
Builds a new collection by applying a function to all elements of this sequence and collecting the results in reversed order.
the element type of the returned collection.
Note: xs.reverseMap(f) is the same as xs.reverse.map(f) but might be more efficient.
the function to apply to each element.
a new sequence resulting from applying the given function
f to each element of this sequence and collecting the results in reversed order.
Builds a new collection by applying a function to all elements of this sequence and collecting the results in reversed order.
Builds a new collection by applying a function to all elements of this sequence and collecting the results in reversed order.
Note: will not terminate for infinite-sized collections.
Note: xs.reverseMap(f) is the same as xs.reverse.map(f) but might be more efficient.
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 the new element type B.
a new collection of type That resulting from applying the given function
f to each element of this sequence and collecting the results in reversed order.
use reverseIterator' instead
[use case] Checks if the other iterable collection contains the same elements in the same order as this sequence.
Checks if the other iterable collection contains the same elements in the same order as this sequence.
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 sequence.
Checks if the other iterable collection contains the same elements in the same order as this sequence.
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 new sequence containing the prefix scan of the elements in this sequence
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 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.
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 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.
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 the new element type B.
collection with intermediate results
Returns the length of the longest segment of elements starting at a given position satisfying some predicate.
Returns the length of the longest segment of elements starting at a given position satisfying some predicate.
This method will use indexFlag signalling capabilities. This means
that splitters may set and read the indexFlag state.
The index flag is initially set to maximum integer value.
the predicate used to test the elements
the starting offset for the search
the length of the longest segment of elements starting at from and
satisfying the predicate
A version of this collection with all of the operations implemented sequentially (i.
A version of this collection with all of the operations implemented sequentially (i.e. in a single-threaded manner).
This method returns a reference to this collection. In parallel collections, it is redefined to return a sequential implementation of this collection. In both cases, it has O(1) complexity.
a sequential view of the collection.
The size of this sequence, equivalent to length.
The size of this sequence, equivalent to length.
Note: will not terminate for infinite-sized collections.@return the number of elements in this sequence.
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
a sequence containing the elements greater than or equal to
index from extending up to (but not including) index until
of this sequence.
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.
Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.)
the number of elements per group
An iterator producing sequences of size size, except the
last and the only element will be truncated if there are
fewer elements than size.
Iterator#sliding
Sorts this Seq according to the Ordering which results from transforming an implicitly given Ordering with a transformation function.
Sorts this Seq according to the Ordering which results from transforming an implicitly given Ordering with a transformation function.
the target type of the transformation f, and the type where
the ordering ord is defined.
the transformation function mapping elements
to some other domain B.
the ordering assumed on domain B.
a sequence consisting of the elements of this sequence
sorted according to the ordering where x < y if
ord.lt(f(x), f(y)).
val words = "The quick brown fox jumped over the lazy dog".split(' ')
// this works because scala.Ordering will implicitly provide an Ordering[Tuple2[Int, Char]]
words.sortBy(x => (x.length, x.head))
res0: Array[String] = Array(The, dog, fox, the, lazy, over, brown, quick, jumped)
scala.math.Ordering
Note: will not terminate for infinite-sized collections.
Sorts this sequence according to a comparison function.
Sorts this sequence according to a comparison function.
Note: will not terminate for infinite-sized collections.
The sort is stable. That is, elements that are equal wrt lt appear in the
same order in the sorted sequence as in the original.
the comparison function which tests whether its first argument precedes its second argument in the desired ordering.
a sequence consisting of the elements of this sequence
sorted according to the comparison function lt.
List("Steve", "Tom", "John", "Bob").sortWith(_.compareTo(_) < 0) =
List("Bob", "John", "Steve", "Tom")
Sorts this sequence according to an Ordering.
Sorts this sequence according to an Ordering.
The sort is stable. That is, elements that are equal wrt lt appear in the
same order in the sorted sequence as in the original.
the ordering to be used to compare elements.
a sequence consisting of the elements of this sequence
sorted according to the ordering ord.
scala.math.Ordering
Splits this sequence into a prefix/suffix pair according to a predicate.
Splits this sequence 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 sequence into two at a given position.
Splits this sequence into two at a given position.
Note: c splitAt n is equivalent to (but possibly more efficient than)
(c take n, c drop n).
the position at which to split.
a pair of sequences consisting of the first n
elements of this sequence, and the other elements.
Tests whether this sequence contains the given sequence at a given index.
Tests whether this sequence contains the given sequence at a given index.
This method will use abort signalling capabilities. This means
that splitters may send and read abort signals.
the parallel sequence this sequence is being searched for
the starting offset for the search
true if there is a sequence that starting at offset in this sequence, false otherwise
Tests whether this sequence starts with the given sequence.
Tests whether this sequence starts with the given sequence.
the sequence to test
true if this collection has that as a prefix, false otherwise.
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 sequence. By default the string prefix is the
simple name of the collection class sequence.
[use case] Sums up the elements of this collection.
Sums up the elements of this collection.
the sum of all elements in this sequence 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 sequence and as result type of sum.
Examples of such types are: Long, Float, Double, BigInt.
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 sequence with respect to the + operator in num.
Selects all elements except the first.
Selects all elements except the first.
a sequence consisting of all elements of this sequence except the first one.
Iterates over the tails of this sequence.
Iterates over the tails of this sequence. The first value will be this
sequence and the final one will be an empty sequence, with the intervening
values the results of successive applications of tail.
an iterator over all the tails of this sequence
List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)
Selects first n elements.
Selects first n elements.
Tt number of elements to take from this sequence.
a sequence consisting only of the first n elements of this sequence,
or else the whole sequence, if it has less than n elements.
Selects last n elements.
Selects last n elements.
the number of elements to take
a sequence consisting only of the last n elements of this sequence, or else the
whole sequence, 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 sequence of elements that satisy the predicate pred
The underlying collection seen as an instance of Seq.
The underlying collection seen as an instance of Seq.
By default this is implemented as the current collection object itself,
but this can be overridden.
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 sequence to an array.
Converts this sequence to an array.
Note: will not terminate for infinite-sized collections.
an array containing all elements of this sequence.
A ClassManifest must be available for the element type of this sequence.
Converts this sequence to an array.
Converts this sequence to an array.
Note: will not terminate for infinite-sized collections.
an array containing all elements of this sequence.
Converts this sequence to a mutable buffer.
Converts this sequence to a mutable buffer.
Note: will not terminate for infinite-sized collections.
a buffer containing all elements of this sequence.
A conversion from collections of type Repr to Seq objects.
A conversion from collections of type Repr to Seq objects.
By default this is implemented as just a cast, but this can be overridden.
Converts this sequence to an indexed sequence.
Converts this sequence to an indexed sequence.
Note: will not terminate for infinite-sized collections.
an indexed sequence containing all elements of this sequence.
Converts this sequence to an iterable collection.
Converts this sequence 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 sequence.
Returns an Iterator over the elements in this sequence.
Returns an Iterator over the elements in this sequence. 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 sequence.
Converts this sequence to a list.
Converts this sequence to a list.
Note: will not terminate for infinite-sized collections.
a list containing all elements of this sequence.
[use case] Converts this sequence to a map.
Converts this sequence 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 sequence.
Converts this sequence to a map.
Converts this sequence 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 sequence.
Converts this sequence to a sequence.
Converts this sequence to a sequence. As with toIterable, it's lazy
in this default implementation, as this TraversableOnce may be
lazy and unevaluated.
Note: will not terminate for infinite-sized collections.
a sequence containing all elements of this sequence.
Converts this sequence to a set.
Converts this sequence to a set.
Note: will not terminate for infinite-sized collections.
a set containing all elements of this sequence.
Converts this sequence to a stream.
Converts this sequence to a stream.
Note: will not terminate for infinite-sized collections.
a stream containing all elements of this sequence.
Converts this sequence to a string.
Converts this sequence to a string.
a string representation of this collection. By default this
string consists of the stringPrefix of this sequence,
followed by all elements separated by commas and enclosed in parentheses.
Converts this sequence to an unspecified Traversable.
Converts this sequence 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 sequence.
[use case] Produces a new sequence which contains all elements of this sequence and also all elements of a given sequence.
Produces a new sequence which contains all elements of this sequence and also all elements of
a given sequence. xs union ys is equivalent to xs ++ ys.
Note: will not terminate for infinite-sized collections.
the sequence to add.
a new sequence which contains all elements of this sequence
followed by all elements of that.
Produces a new sequence which contains all elements of this sequence and also all elements of a given sequence.
Produces a new sequence which contains all elements of this sequence and also all elements of
a given sequence. xs union ys is equivalent to xs ++ ys.
Note: will not terminate for infinite-sized collections.
Another way to express this
is that xs union ys computes the order-presevring multi-set union of xs and ys.
union is hence a counter-part of diff and intersect which also work on multi-sets.
Note: will not terminate for infinite-sized collections.
the element type of the returned sequence.
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 sequence to add.
an implicit value of class CanBuildFrom which determines the
result class That from the current representation type Repr
and the new element type B.
a new collection of type That which contains all elements of this sequence
followed by all elements of that.
[use case] A copy of this sequence with one single replaced element.
A copy of this sequence with one single replaced element.
the position of the replacement
the replacing element
a copy of this sequence with the element at position index replaced by elem.
A copy of this sequence with one single replaced element.
A copy of this sequence with one single replaced element.
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 position of the replacement
the replacing element
an implicit value of class CanBuildFrom which determines the
result class That from the current representation type Repr
and the new element type B.
a new sequence which is a copy of this sequence with the element at position index replaced by elem.
Creates a non-strict view of a slice of this sequence.
Creates a non-strict view of a slice of this sequence.
Note: the difference between view and slice is that view produces
a view of the current sequence, whereas slice produces a new sequence.
Note: view(from, to) is equivalent to view.slice(from, to)
the index of the first element of the view
the index of the element following the view
a non-strict view of a slice of this sequence, starting at index from
and extending up to (but not including) index until.
Creates a non-strict view of this sequence.
Creates a non-strict view of this sequence.
a non-strict view of this sequence.
Creates a non-strict filter of this sequence.
Creates a non-strict filter of this sequence.
Note: the difference between c filter p and c withFilter p is that
the former creates a new collection, whereas the latter only
restricts the domain of subsequent map, flatMap, foreach,
and withFilter operations.
the predicate used to test elements.
an object of class WithFilter, which supports
map, flatMap, foreach, and withFilter operations.
All these operations apply to those elements of this sequence which
satisfy the predicate p.
[use case] Returns a sequence formed from this sequence and another iterable collection by combining corresponding elements in pairs.
Returns a sequence formed from this sequence 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 sequence containing pairs consisting of
corresponding elements of this sequence and that. The length
of the returned collection is the minimum of the lengths of this sequence and that.
Returns a sequence formed from this sequence and another iterable collection by combining corresponding elements in pairs.
Returns a sequence formed from this sequence 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 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 sequence and that. The length
of the returned collection is the minimum of the lengths of this sequence and that.
[use case] Returns a sequence formed from this sequence and another iterable collection by combining corresponding elements in pairs.
Returns a sequence formed from this sequence 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 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 sequence is shorter than that.
the element to be used to fill up the result if that is shorter than this sequence.
a new sequence containing pairs consisting of
corresponding elements of this sequence and that. The length
of the returned collection is the maximum of the lengths of this sequence and that.
If this sequence is shorter than that, thisElem values are used to pad the result.
If that is shorter than this sequence, thatElem values are used to pad the result.
Returns a sequence formed from this sequence and another iterable collection by combining corresponding elements in pairs.
Returns a sequence formed from this sequence 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 sequence is shorter than that.
the element to be used to fill up the result if that is shorter than this sequence.
a new collection of type That containing pairs consisting of
corresponding elements of this sequence and that. The length
of the returned collection is the maximum of the lengths of this sequence and that.
If this sequence is shorter than that, thisElem values are used to pad the result.
If that is shorter than this sequence, thatElem values are used to pad the result.
[use case] Zips this sequence with its indices.
Zips this sequence with its indices.
A new sequence containing pairs consisting of all elements of this
sequence paired with their index. Indices start at 0.
@example
List("a", "b", "c").zipWithIndex = List(("a", 0), ("b", 1), ("c", 2))
Zips this sequence with its indices.
Zips this sequence with its indices.
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
sequence paired with their index. Indices start at 0.
A template trait for sequences of type
ParSeq[T], representing parallel sequences with element typeT.Parallel sequences inherit the
Seqtrait. Their indexing and length computations are defined to be efficient. Like their sequential counterparts they always have a defined order of elements. This means they will produce resulting parallel sequences in the same way sequential sequences do. However, the order in which they perform bulk operations on elements to produce results is not defined and is generally nondeterministic. If the higher-order functions given to them produce no sideeffects, then this won't be noticeable.This trait defines a new, more general
splitoperation and reimplements thesplitoperation ofParallelIterabletrait using the newsplitoperation.