AnyBidirectionalCollection
A type-erased wrapper over any collection with indices that support bidirectional traversal.
@frozen struct AnyBidirectionalCollection<Element>An AnyBidirectionalCollection instance forwards its operations to a base collection having the same Element type, hiding the specifics of the underlying collection.
Citizens in Swift
Conformances
protocol BidirectionalCollectionA collection that supports backward as well as forward traversal.
protocol CollectionA sequence whose elements can be traversed multiple times, nondestructively, and accessed by an indexed subscript.
protocol SequenceA type that provides sequential, iterated access to its elements.
Members
init(AnyBidirectionalCollection<Element>) Creates an
AnyBidirectionalCollectionhaving the same underlying collection asother.init?(AnyCollection<Element>) Creates an
AnyBidirectionalCollectionhaving the same underlying collection asother.init<C>(C) Creates a type-erased collection that wraps the given collection.
init<C>(C) Creates a type-erased collection that wraps the given collection.
init(AnyRandomAccessCollection<Element>) Creates an
AnyBidirectionalCollectionhaving the same underlying collection asother.var count: IntThe number of elements.
var endIndex: AnyBidirectionalCollection<Element>.IndexThe collection’s “past the end” position—that is, the position one greater than the last valid subscript argument.
var startIndex: AnyBidirectionalCollection<Element>.IndexThe position of the first element in a non-empty collection.
var underestimatedCount: Intsubscript(Range<AnyBidirectionalCollection<Element>.Index>) -> AnyBidirectionalCollection<Element>.SubSequence subscript(AnyBidirectionalCollection<Element>.Index) -> Element Accesses the element indicated by
position.func distance(from: AnyBidirectionalCollection<Element>.Index, to: AnyBidirectionalCollection<Element>.Index) -> Int func drop(while: (Element) throws -> Bool) rethrows -> AnyBidirectionalCollection<Element> func dropFirst(Int) -> AnyBidirectionalCollection<Element> func dropLast(Int) -> AnyBidirectionalCollection<Element> func filter((Element) throws -> Bool) rethrows -> [Element] func forEach((Element) throws -> Void) rethrows func formIndex(inout AnyBidirectionalCollection<Element>.Index, offsetBy: Int) func formIndex(inout AnyBidirectionalCollection<Element>.Index, offsetBy: Int, limitedBy: AnyBidirectionalCollection<Element>.Index) -> Bool func formIndex(after: inout AnyBidirectionalCollection<Element>.Index) func formIndex(before: inout AnyBidirectionalCollection<Element>.Index) func index(AnyBidirectionalCollection<Element>.Index, offsetBy: Int) -> AnyBidirectionalCollection<Element>.Index func index(AnyBidirectionalCollection<Element>.Index, offsetBy: Int, limitedBy: AnyBidirectionalCollection<Element>.Index) -> AnyBidirectionalCollection<Element>.Index? func index(after: AnyBidirectionalCollection<Element>.Index) -> AnyBidirectionalCollection<Element>.Index func index(before: AnyBidirectionalCollection<Element>.Index) -> AnyBidirectionalCollection<Element>.Index func makeIterator() -> AnyBidirectionalCollection<Element>.Iterator Returns an iterator over the elements of this collection.
func map<T>((Element) throws -> T) rethrows -> [T] func prefix(Int) -> AnyBidirectionalCollection<Element> func prefix(while: (Element) throws -> Bool) rethrows -> AnyBidirectionalCollection<Element> func suffix(Int) -> AnyBidirectionalCollection<Element> typealias Indextypealias Indicestypealias Iteratortypealias SubSequence
Features
var first: Self.Element?The first element of the collection.
var last: Self.Element?The last element of the collection.
var lazy: LazySequence<Self>A sequence containing the same elements as this sequence, but on which some operations, such as
mapandfilter, are implemented lazily.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-
nilresults of calling the given transformation with each element of this 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 difference<C>(from: C) -> CollectionDifference<Self.Element> Returns the difference needed to produce this collection’s ordered elements from the given collection.
func difference<C>(from: C, by: (C.Element, Self.Element) -> Bool) -> CollectionDifference<Self.Element> Returns the difference needed to produce this collection’s ordered elements from the given collection, using the given predicate as an equivalence test.
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 first(where: (Self.Element) throws -> Bool) rethrows -> Self.Element? Returns the first element of the sequence that satisfies the given predicate.
func firstIndex(of: Self.Element) -> Self.Index? Returns the first index where the specified value appears in the collection.
func firstIndex(where: (Self.Element) throws -> Bool) rethrows -> Self.Index? Returns the first index in which an element of the collection satisfies the given predicate.
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 joined() -> FlattenSequence<Self> Returns the elements of this sequence of sequences, concatenated.
func joined(separator: String) -> String Returns a new string by concatenating the elements of the sequence, adding the given separator between each element.
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 last(where: (Self.Element) throws -> Bool) rethrows -> Self.Element? Returns the last element of the sequence that satisfies the given predicate.
func lastIndex(of: Self.Element) -> Self.Index? Returns the last index where the specified value appears in the collection.
func lastIndex(where: (Self.Element) throws -> Bool) rethrows -> Self.Index? Returns the index of the last element in the collection that matches the given predicate.
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>((Self.Element) throws -> T) rethrows -> [T] Returns an array containing the results of mapping the given closure over the sequence’s elements.
func map<T>((Self.Element) throws -> T) rethrows -> [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 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 popFirst() -> Self.Element? Removes and returns the first element of the collection.
func popLast() -> Self.Element? Removes and returns the last element of the collection.
func prefix(through: Self.Index) -> Self.SubSequence Returns a subsequence from the start of the collection through the specified position.
func prefix(upTo: Self.Index) -> Self.SubSequence Returns a subsequence from the start of the collection up to, but not including, the specified position.
func randomElement() -> Self.Element? Returns a random element of the collection.
func randomElement<T>(using: inout T) -> Self.Element? Returns a random element of the collection, using the given generator as a source for randomness.
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 removeFirst() -> Self.Element Removes and returns the first element of the collection.
func removeFirst(Int) Removes the specified number of elements from the beginning of the collection.
func removeLast() -> Self.Element Removes and returns the last element of the collection.
func removeLast(Int) Removes the given number of elements from the end of the collection.
func reversed() -> ReversedCollection<Self> Returns a view presenting the elements of the collection 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 -> [Self.SubSequence] Returns the longest possible subsequences of the collection, in order, that don’t contain elements satisfying the given predicate.
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 split(separator: Self.Element, maxSplits: Int, omittingEmptySubsequences: Bool) -> [Self.SubSequence] Returns the longest possible subsequences of the collection, 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 suffix(from: Self.Index) -> Self.SubSequence Returns a subsequence from the specified position to the end of the collection.
func flatMap<ElementOfResult>((Self.Element) throws -> ElementOfResult?) rethrows -> [ElementOfResult] func index(of: Self.Element) -> Self.Index? Returns the first index where the specified value appears in the collection.