var lazy: LazySequence<Self>
A sequence containing the same elements as this sequence, but on which some operations, such as map
and filter
, are implemented lazily.
var underestimatedCount: Int
A value less than or equal to the number of elements in the sequence, calculated nondestructively.
func adjacentPairs() -> AdjacentPairsSequence<Self>
Returns a sequence of overlapping adjacent pairs of the elements of this sequence.
func allSatisfy((Self.Element) throws -> Bool) rethrows -> Bool
Returns a Boolean value indicating whether every element of a sequence satisfies a given predicate.
func compactMap<ElementOfResult>((Self.Element) throws -> ElementOfResult?) rethrows -> [ElementOfResult]
Returns an array containing the non-nil
results of calling the given transformation with each element of this sequence.
func compacted<Unwrapped>() -> CompactedSequence<Self, Unwrapped>
Returns a new Sequence
that iterates over every non-nil element from the original Sequence
.
func contains(Self.Element) -> Bool
Returns a Boolean value indicating whether the sequence contains the given element.
func contains(where: (Self.Element) throws -> Bool) rethrows -> Bool
Returns a Boolean value indicating whether the sequence contains an element that satisfies the given predicate.
func count<E>(where: (Self.Element) throws(E) -> Bool) throws(E) -> Int
Returns the number of elements in the sequence that satisfy the given predicate.
func drop(while: (Self.Element) throws -> Bool) rethrows -> DropWhileSequence<Self>
Returns a sequence by skipping the initial, consecutive elements that satisfy the given predicate.
func dropFirst(Int) -> DropFirstSequence<Self>
Returns a sequence containing all but the given number of initial elements.
func dropLast(Int) -> [Self.Element]
Returns a sequence containing all but the given number of final elements.
func elementsEqual<OtherSequence>(OtherSequence) -> Bool
Returns a Boolean value indicating whether this sequence and another sequence contain the same elements in the same order.
func elementsEqual<OtherSequence>(OtherSequence, by: (Self.Element, OtherSequence.Element) throws -> Bool) rethrows -> Bool
Returns a Boolean value indicating whether this sequence and another sequence contain equivalent elements in the same order, using the given predicate as the equivalence test.
func enumerated() -> EnumeratedSequence<Self>
Returns a sequence of pairs (n, x), where n represents a consecutive integer starting at zero and x represents an element of the sequence.
func filter((Self.Element) throws -> Bool) rethrows -> [Self.Element]
Returns an array containing, in order, the elements of the sequence that satisfy the given predicate.
func first(where: (Self.Element) throws -> Bool) rethrows -> Self.Element?
Returns the first element of the sequence that satisfies the given predicate.
func firstNonNil<Result>((Element) throws -> Result?) rethrows -> Result?
Returns the first non-nil
result obtained from applying the given transformation to the elements of the sequence.
func flatMap<SegmentOfResult>((Self.Element) throws -> SegmentOfResult) rethrows -> [SegmentOfResult.Element]
Returns an array containing the concatenated results of calling the given transformation with each element of this sequence.
func forEach((Self.Element) throws -> Void) rethrows
Calls the given closure on each element in the sequence in the same order as a for
-in
loop.
func grouped<GroupKey>(by: (Element) throws -> GroupKey) rethrows -> [GroupKey : [Element]]
Groups up elements of self
into a new Dictionary, whose values are Arrays of grouped elements, each keyed by the group key returned by the given closure.
func interspersed(with: Element) -> InterspersedSequence<Self>
Returns a sequence containing elements of this sequence with the given separator inserted in between each element.
func joined() -> FlattenSequence<Self>
Returns the elements of this sequence of sequences, concatenated.
func joined<Separator>(by: Separator) -> JoinedBySequence<Self, Separator>
Returns the concatenation of the elements in this sequence of sequences, inserting the given separator between each sequence.
func joined(by: Element.Element) -> JoinedBySequence<Self, CollectionOfOne<Element.Element>>
Returns the concatenation of the elements in this sequence of sequences, inserting the given separator between each sequence.
func joined<Separator>(by: (Element, Element) throws -> Separator) rethrows -> [Element.Element]
Returns the concatenation of the elements in this sequence of sequences, inserting the separator produced by the closure between each sequence.
func joined(by: (Element, Element) throws -> Element.Element) rethrows -> [Element.Element]
Returns the concatenation of the elements in this sequence of sequences, inserting the separator produced by the closure between each sequence.
func joined<Separator>(separator: Separator) -> JoinedSequence<Self>
Returns the concatenated elements of this sequence of sequences, inserting the given separator between each element.
func joined(separator: String) -> String
Returns a new string by concatenating the elements of the sequence, adding the given separator between each element.
func keyed<Key>(by: (Element) throws -> Key) rethrows -> [Key : Element]
Creates a new Dictionary from the elements of self
, keyed by the results returned by the given keyForValue
closure.
func keyed<Key>(by: (Element) throws -> Key, resolvingConflictsWith: (Key, Element, Element) throws -> Element) rethrows -> [Key : Element]
Creates a new Dictionary from the elements of self
, keyed by the results returned by the given keyForValue
closure. As the dictionary is built, the initializer calls the resolve
closure with the current and new values for any duplicate keys. Pass a closure as resolve
that returns the value to use in the resulting dictionary: The closure can choose between the two values, combine them to produce a new value, or even throw an error.
func lexicographicallyPrecedes<OtherSequence>(OtherSequence) -> Bool
Returns a Boolean value indicating whether the sequence precedes another sequence in a lexicographical (dictionary) ordering, using the less-than operator (<
) to compare elements.
func lexicographicallyPrecedes<OtherSequence>(OtherSequence, by: (Self.Element, Self.Element) throws -> Bool) rethrows -> Bool
Returns a Boolean value indicating whether the sequence precedes another sequence in a lexicographical (dictionary) ordering, using the given predicate to compare elements.
func map<T, E>((Self.Element) throws(E) -> T) throws(E) -> [T]
Returns an array containing the results of mapping the given closure over the sequence’s elements.
func max() -> Self.Element?
Returns the maximum element in the sequence.
func max(by: (Self.Element, Self.Element) throws -> Bool) rethrows -> Self.Element?
Returns the maximum element in the sequence, using the given predicate as the comparison between elements.
func max(count: Int) -> [Element]
Returns the largest elements of this sequence.
func max(count: Int, sortedBy: (Element, Element) throws -> Bool) rethrows -> [Element]
Returns the largest elements of this sequence, as sorted by the given predicate.
func min() -> Self.Element?
Returns the minimum element in the sequence.
func min(by: (Self.Element, Self.Element) throws -> Bool) rethrows -> Self.Element?
Returns the minimum element in the sequence, using the given predicate as the comparison between elements.
func min(count: Int) -> [Element]
Returns the smallest elements of this sequence.
func min(count: Int, sortedBy: (Element, Element) throws -> Bool) rethrows -> [Element]
Returns the smallest elements of this sequence, as sorted by the given predicate.
func minAndMax() -> (min: Element, max: Element)?
Returns both the minimum and maximum elements in the sequence.
func minAndMax(by: (Element, Element) throws -> Bool) rethrows -> (min: Element, max: Element)?
Returns both the minimum and maximum elements in the sequence, using the given predicate as the comparison between elements.
func partitioned(by: (Element) throws -> Bool) rethrows -> (falseElements: [Element], trueElements: [Element])
Returns two arrays containing the elements of the sequence that don’t and do satisfy the given predicate, respectively.
func prefix(Int) -> PrefixSequence<Self>
Returns a sequence, up to the specified maximum length, containing the initial elements of the sequence.
func prefix(while: (Self.Element) throws -> Bool) rethrows -> [Self.Element]
Returns a sequence containing the initial, consecutive elements that satisfy the given predicate.
func randomSample(count: Int) -> [Element]
Randomly selects the specified number of elements from this sequence.
func randomSample<G>(count: Int, using: inout G) -> [Element]
Randomly selects the specified number of elements from this sequence.
func reduce<Result>(Result, (Result, Self.Element) throws -> Result) rethrows -> Result
Returns the result of combining the elements of the sequence using the given closure.
func reduce<Result>(into: Result, (inout Result, Self.Element) throws -> ()) rethrows -> Result
Returns the result of combining the elements of the sequence using the given closure.
func reductions((Element, Element) throws -> Element) rethrows -> [Element]
Returns an array containing the accumulated results of combining the elements of the sequence using the given closure.
func reductions<Result>(Result, (Result, Element) throws -> Result) rethrows -> [Result]
Returns an array containing the accumulated results of combining the elements of the sequence using the given closure.
func reductions<Result>(into: Result, (inout Result, Element) throws -> Void) rethrows -> [Result]
Returns an array containing the accumulated results of combining the elements of the sequence using the given closure.
func reversed() -> [Self.Element]
Returns an array containing the elements of this sequence in reverse order.
func shuffled() -> [Self.Element]
Returns the elements of the sequence, shuffled.
func shuffled<T>(using: inout T) -> [Self.Element]
Returns the elements of the sequence, shuffled using the given generator as a source for randomness.
func sorted() -> [Self.Element]
Returns the elements of the sequence, sorted.
func sorted(by: (Self.Element, Self.Element) throws -> Bool) rethrows -> [Self.Element]
Returns the elements of the sequence, sorted using the given predicate as the comparison between elements.
func split(maxSplits: Int, omittingEmptySubsequences: Bool, whereSeparator: (Self.Element) throws -> Bool) rethrows -> [ArraySlice<Self.Element>]
Returns the longest possible subsequences of the sequence, in order, that don’t contain elements satisfying the given predicate. Elements that are used to split the sequence are not returned as part of any subsequence.
func split(separator: Self.Element, maxSplits: Int, omittingEmptySubsequences: Bool) -> [ArraySlice<Self.Element>]
Returns the longest possible subsequences of the sequence, in order, around elements equal to the given element.
func starts<PossiblePrefix>(with: PossiblePrefix) -> Bool
Returns a Boolean value indicating whether the initial elements of the sequence are the same as the elements in another sequence.
func starts<PossiblePrefix>(with: PossiblePrefix, by: (Self.Element, PossiblePrefix.Element) throws -> Bool) rethrows -> Bool
Returns a Boolean value indicating whether the initial elements of the sequence are equivalent to the elements in another sequence, using the given predicate as the equivalence test.
func striding(by: Int) -> StridingSequence<Self>
Returns a sequence stepping through the elements every step
starting at the first value. Any remainders of the stride will be trimmed.
func suffix(Int) -> [Self.Element]
Returns a subsequence, up to the given maximum length, containing the final elements of the sequence.
func uniqued() -> UniquedSequence<Self, Element>
Returns a sequence with only the unique elements of this sequence, in the order of the first occurrence of each unique element.
func uniqued<Subject>(on: (Element) throws -> Subject) rethrows -> [Element]
Returns an array with the unique elements of this sequence (as determined by the given projection), in the order of the first occurrence of each unique element.
func withContiguousStorageIfAvailable<R>((UnsafeBufferPointer<Self.Element>) throws -> R) rethrows -> R?