Generic Structure

AnyRandomAccessCollection

A type-erased wrapper over any collection with indices that support random access traversal.

Declaration

@frozen struct AnyRandomAccessCollection<Element>

Overview

An AnyRandomAccessCollection instance forwards its operations to a base collection having the same Element type, hiding the specifics of the underlying collection.

Topics

Type Aliases

typealias AnyRandomAccessCollection.Index

A type that represents a position in the collection.

typealias AnyRandomAccessCollection.Indices

A type that represents the indices that are valid for subscripting the collection, in ascending order.

typealias AnyRandomAccessCollection.Iterator

A type that provides the collection’s iteration interface and encapsulates its iteration state.

typealias AnyRandomAccessCollection.SubSequence

A sequence that represents a contiguous subrange of the collection’s elements.

Initializers

init(AnyRandomAccessCollection<Element>)

Creates an AnyRandomAccessCollection having the same underlying collection as other.

init?(AnyBidirectionalCollection<Element>)

Creates an AnyRandomAccessCollection having the same underlying collection as other.

init?(AnyCollection<Element>)

Creates an AnyRandomAccessCollection having the same underlying collection as other.

init<C>(C)

Creates a type-erased collection that wraps the given collection.

Instance Properties

var count: Int

The number of elements.

var endIndex: AnyRandomAccessCollection<Element>.Index

The collection’s “past the end” position—that is, the position one greater than the last valid subscript argument.

var first: Element?

The first element of the collection.

var indices: DefaultIndices<AnyRandomAccessCollection<Element>>

The indices that are valid for subscripting the collection, in ascending order.

var isEmpty: Bool

A Boolean value indicating whether the collection is empty.

var last: Element?

The last element of the collection.

var lazy: LazySequence<AnyRandomAccessCollection<Element>>

A sequence containing the same elements as this sequence, but on which some operations, such as map and filter, are implemented lazily.

var startIndex: AnyRandomAccessCollection<Element>.Index

The position of the first element in a non-empty collection.

var underestimatedCount: Int

A value less than or equal to the number of elements in the sequence, calculated nondestructively.

Instance Methods

func allSatisfy((Element) -> Bool) -> Bool

Returns a Boolean value indicating whether every element of a sequence satisfies a given predicate.

func compactMap<ElementOfResult>((Element) -> ElementOfResult?) -> [ElementOfResult]

Returns an array containing the non-nil results of calling the given transformation with each element of this sequence.

func contains(Element) -> Bool

Returns a Boolean value indicating whether the sequence contains the given element.

func contains(where: (Element) -> Bool) -> Bool

Returns a Boolean value indicating whether the sequence contains an element that satisfies the given predicate.

func difference<C>(from: C) -> CollectionDifference<Element>

Returns the difference needed to produce this collection’s ordered elements from the given collection.

func difference<C>(from: C, by: (C.Element, Element) -> Bool) -> CollectionDifference<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: (Element, OtherSequence.Element) -> Bool) -> 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<AnyRandomAccessCollection<Element>>

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: (Element) -> Bool) -> Element?

Returns the first element of the sequence that satisfies the given predicate.

func firstIndex(of: Element) -> AnyIndex?

Returns the first index where the specified value appears in the collection.

func firstIndex(where: (Element) -> Bool) -> AnyIndex?

Returns the first index in which an element of the collection satisfies the given predicate.

func flatMap<SegmentOfResult>((Element) -> SegmentOfResult) -> [SegmentOfResult.Element]

Returns an array containing the concatenated results of calling the given transformation with each element of this sequence.

func index(AnyRandomAccessCollection<Element>.Index, offsetBy: Int, limitedBy: AnyRandomAccessCollection<Element>.Index) -> AnyRandomAccessCollection<Element>.Index?

Returns an index that is the specified distance from the given index, unless that distance is beyond a given limiting index.

func index(of: Element) -> AnyIndex?

Returns the first index where the specified value appears in the collection.

Deprecated
func index(where: (Element) -> Bool) -> AnyIndex?

Returns the first index in which an element of the collection satisfies the given predicate.

Deprecated
func joined() -> FlattenSequence<AnyRandomAccessCollection<Element>>

Returns the elements of this sequence of sequences, concatenated.

func joined<Separator>(separator: Separator) -> JoinedSequence<AnyRandomAccessCollection<Element>>

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 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: (Element) -> Bool) -> Element?

Returns the last element of the sequence that satisfies the given predicate.

func lastIndex(of: Element) -> AnyIndex?

Returns the last index where the specified value appears in the collection.

func lastIndex(where: (Element) -> Bool) -> AnyIndex?

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: (Element, Element) -> Bool) -> 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 makeIterator() -> AnyRandomAccessCollection<Element>.Iterator

Returns an iterator over the elements of this collection.

func max() -> Element?

Returns the maximum element in the sequence.

func max(by: (Element, Element) -> Bool) -> Element?

Returns the maximum element in the sequence, using the given predicate as the comparison between elements.

func min() -> Element?

Returns the minimum element in the sequence.

func min(by: (Element, Element) -> Bool) -> Element?

Returns the minimum element in the sequence, using the given predicate as the comparison between elements.

func popFirst() -> Element?

Removes and returns the first element of the collection.

func popLast() -> Element?

Removes and returns the last element of the collection.

func prefix(through: AnyIndex) -> AnyRandomAccessCollection<Element>

Returns a subsequence from the start of the collection through the specified position.

func prefix(upTo: AnyIndex) -> AnyRandomAccessCollection<Element>

Returns a subsequence from the start of the collection up to, but not including, the specified position.

func randomElement() -> Element?

Returns a random element of the collection.

func randomElement<T>(using: inout T) -> Element?

Returns a random element of the collection, using the given generator as a source for randomness.

func reduce<Result>(Result, (Result, Element) -> Result) -> Result

Returns the result of combining the elements of the sequence using the given closure.

func reduce<Result>(into: Result, (inout Result, Element) -> ()) -> Result

Returns the result of combining the elements of the sequence using the given closure.

func removeFirst() -> 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() -> 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<AnyRandomAccessCollection<Element>>

Returns a view presenting the elements of the collection in reverse order.

func shuffled() -> [Element]

Returns the elements of the sequence, shuffled.

func shuffled<T>(using: inout T) -> [Element]

Returns the elements of the sequence, shuffled using the given generator as a source for randomness.

func sorted() -> [Element]

Returns the elements of the sequence, sorted.

func sorted(by: (Element, Element) -> Bool) -> [Element]

Returns the elements of the sequence, sorted using the given predicate as the comparison between elements.

func split(maxSplits: Int, omittingEmptySubsequences: Bool, whereSeparator: (Element) -> Bool) -> [AnyRandomAccessCollection<Element>]

Returns the longest possible subsequences of the collection, in order, that don’t contain elements satisfying the given predicate.

func split(separator: Element, maxSplits: Int, omittingEmptySubsequences: Bool) -> [AnyRandomAccessCollection<Element>]

Returns the longest possible subsequences of the collection, in order, around elements equal to the given element.

func split(separator: Element, maxSplits: Int, omittingEmptySubsequences: Bool) -> [ArraySlice<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: (Element, PossiblePrefix.Element) -> Bool) -> 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: AnyIndex) -> AnyRandomAccessCollection<Element>

Returns a subsequence from the specified position to the end of the collection.

func withContiguousStorageIfAvailable<R>((UnsafeBufferPointer<Element>) -> R) -> R?

Call body(p), where p is a pointer to the collection’s contiguous storage. If no such storage exists, it is first created. If the collection does not support an internal representation in a form of contiguous storage, body is not called and nil is returned.

Subscripts

subscript(AnyRandomAccessCollection<Element>.Index) -> Element

Accesses the element indicated by position.

subscript<R>(R) -> AnyRandomAccessCollection<Element>

Accesses the contiguous subrange of the collection’s elements specified by a range expression.

Relationships

See Also

Type-Erasing Wrappers

struct AnySequence

A type-erased sequence.

struct AnyCollection

A type-erased wrapper over any collection with indices that support forward traversal.

struct AnyBidirectionalCollection

A type-erased wrapper over any collection with indices that support bidirectional traversal.

struct AnyIterator

A type-erased iterator of Element.

struct AnyIndex

A wrapper over an underlying index that hides the specific underlying type.

struct AnyHashable

A type-erased hashable value.