A Sequence whose elements consist of those in a Base Sequence passed through a transform function returning Element. These elements are computed lazily, each time they’re read, by calling the transform function on a base element.
@frozen struct LazyMapSequence<Base, Element> where Base : Sequenceimport Swiftprotocol Sequence<Element>A type that provides sequential, iterated access to its elements.
typealias Elements = LazyMapSequence<Base, Element>protocol BidirectionalCollection<Element> : Collection where Self.Indices : BidirectionalCollection, Self.SubSequence : BidirectionalCollectionA collection that supports backward as well as forward traversal.
func formIndex(before i: inout LazyMapSequence<Base, Element>.Index) func index(before i: LazyMapSequence<Base, Element>.Index) -> LazyMapSequence<Base, Element>.Index A value less than or equal to the number of elements in the collection.
protocol CopyableA type whose values can be implicitly or explicitly copied.
protocol Escapablevar last: Self.Element? { get }The last element of the collection.
func difference<C>(from other: C) -> CollectionDifference<Self.Element> where C : BidirectionalCollection, Self.Element == C.Element Returns the difference needed to produce this collection’s ordered elements from the given collection.
func difference<C>(from other: C, by areEquivalent: (C.Element, Self.Element) -> Bool) -> CollectionDifference<Self.Element> where C : BidirectionalCollection, Self.Element == C.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 distance(from start: Self.Index, to end: Self.Index) -> Int func formIndex(before i: inout Self.Index) func index(_ i: Self.Index, offsetBy distance: Int) -> Self.Index func index(_ i: Self.Index, offsetBy distance: Int, limitedBy limit: Self.Index) -> Self.Index? 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 predicate: (Self.Element) throws -> Bool) rethrows -> Self.Element? Returns the last element of the sequence that satisfies the given predicate.
func lastIndex(of element: Self.Element) -> Self.Index? Returns the last index where the specified value appears in the collection.
func lastIndex(where predicate: (Self.Element) throws -> Bool) rethrows -> Self.Index? Returns the index of the last element in the collection that matches the given predicate.
var underestimatedCount: Int { get }func makeIterator() -> LazyMapSequence<Base, Element>.Iterator Returns an iterator over the elements of this sequence.
func map<ElementOfResult>(_ transform: @escaping (Element) -> ElementOfResult) -> LazyMapSequence<Base, ElementOfResult> @frozen struct Iteratorprotocol LazySequenceProtocol : SequenceA sequence on which normally-eager sequence operations are implemented lazily.
var elements: Self { get }Identical to self.
var lazy: Self.Elements { get }func allSatisfy(_ predicate: (Self.Element) throws -> Bool) rethrows -> Bool Returns a Boolean value indicating whether every element of a sequence satisfies a given predicate.
func compactMap<ElementOfResult>(_ transform: (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 compactMap<ElementOfResult>(_ transform: @escaping (Self.Elements.Element) -> ElementOfResult?) -> LazyMapSequence<LazyFilterSequence<LazyMapSequence<Self.Elements, ElementOfResult?>>, ElementOfResult> Returns the non-nil results of mapping the given transformation over this sequence.
func contains(_ element: Self.Element) -> Bool Returns a Boolean value indicating whether the sequence contains the given element.
func contains(where predicate: (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 predicate: (Self.Element) throws(E) -> Bool) throws(E) -> Int where E : Error Returns the number of elements in the sequence that satisfy the given predicate.
func drop(while predicate: @escaping (Self.Elements.Element) -> Bool) -> LazyDropWhileSequence<Self.Elements> Returns a lazy sequence that skips any initial elements that satisfy predicate.
func dropFirst(_ k: Int = 1) -> DropFirstSequence<Self> Returns a sequence containing all but the given number of initial elements.
func dropLast(_ k: Int = 1) -> [Self.Element] Returns a sequence containing all but the given number of final elements.
func elementsEqual<OtherSequence>(_ other: OtherSequence) -> Bool where OtherSequence : Sequence, Self.Element == OtherSequence.Element Returns a Boolean value indicating whether this sequence and another sequence contain the same elements in the same order.
func elementsEqual<OtherSequence>(_ other: OtherSequence, by areEquivalent: (Self.Element, OtherSequence.Element) throws -> Bool) rethrows -> Bool where OtherSequence : Sequence 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(_ isIncluded: @escaping (Self.Elements.Element) -> Bool) -> LazyFilterSequence<Self.Elements> Returns the elements of self that satisfy isIncluded.
func first(where predicate: (Self.Element) throws -> Bool) rethrows -> Self.Element? Returns the first element of the sequence that satisfies the given predicate.
func flatMap<SegmentOfResult>(_ transform: (Self.Element) throws -> SegmentOfResult) rethrows -> [SegmentOfResult.Element] where SegmentOfResult : Sequence Returns an array containing the concatenated results of calling the given transformation with each element of this sequence.
func flatMap<SegmentOfResult>(_ transform: @escaping (Self.Elements.Element) -> SegmentOfResult) -> LazySequence<FlattenSequence<LazyMapSequence<Self.Elements, SegmentOfResult>>> where SegmentOfResult : Sequence Returns the concatenated results of mapping the given transformation over this sequence.
func forEach(_ body: (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 joined() -> FlattenSequence<Self> Returns the elements of this sequence of sequences, concatenated.
func joined() -> LazySequence<FlattenSequence<Self.Elements>> Returns a lazy sequence that concatenates the elements of this sequence of sequences.
func joined<Separator>(separator: Separator) -> JoinedSequence<Self> where Separator : Sequence, Separator.Element == Self.Element.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 lexicographicallyPrecedes<OtherSequence>(_ other: OtherSequence) -> Bool where OtherSequence : Sequence, Self.Element == OtherSequence.Element 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>(_ other: OtherSequence, by areInIncreasingOrder: (Self.Element, Self.Element) throws -> Bool) rethrows -> Bool where OtherSequence : Sequence, Self.Element == OtherSequence.Element 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>(_ transform: (Self.Element) throws(E) -> T) throws(E) -> [T] where E : Error Returns an array containing the results of mapping the given closure over the sequence’s elements.
func map<U>(_ transform: @escaping (Self.Element) -> U) -> LazyMapSequence<Self.Elements, U> Returns a LazyMapSequence over this Sequence. The elements of the result are computed lazily, each time they are read, by calling transform function on a base element.
@warn_unqualified_access func max() -> Self.Element? Returns the maximum element in the sequence.
@warn_unqualified_access func max(by areInIncreasingOrder: (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.
@warn_unqualified_access func min() -> Self.Element? Returns the minimum element in the sequence.
@warn_unqualified_access func min(by areInIncreasingOrder: (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 prefix(_ maxLength: Int) -> PrefixSequence<Self> Returns a sequence, up to the specified maximum length, containing the initial elements of the sequence.
func prefix(while predicate: @escaping (Self.Elements.Element) -> Bool) -> LazyPrefixWhileSequence<Self.Elements> Returns a lazy sequence of the initial consecutive elements that satisfy predicate.
func reduce<Result>(_ initialResult: Result, _ nextPartialResult: (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 initialResult: Result, _ updateAccumulatingResult: (inout Result, Self.Element) throws -> ()) rethrows -> Result Returns the result 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 generator: inout T) -> [Self.Element] where T : RandomNumberGenerator 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 areInIncreasingOrder: (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 = Int.max, omittingEmptySubsequences: Bool = true, whereSeparator isSeparator: (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 = Int.max, omittingEmptySubsequences: Bool = true) -> [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: PossiblePrefix) -> Bool where PossiblePrefix : Sequence, Self.Element == PossiblePrefix.Element 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: PossiblePrefix, by areEquivalent: (Self.Element, PossiblePrefix.Element) throws -> Bool) rethrows -> Bool where PossiblePrefix : Sequence 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(_ maxLength: Int) -> [Self.Element] Returns a subsequence, up to the given maximum length, containing the final elements of the sequence.
func withContiguousStorageIfAvailable<R>(_ body: (UnsafeBufferPointer<Self.Element>) throws -> R) rethrows -> R? func flatMap<ElementOfResult>(_ transform: (Self.Element) throws -> ElementOfResult?) rethrows -> [ElementOfResult] func flatMap<ElementOfResult>(_ transform: @escaping (Self.Elements.Element) -> ElementOfResult?) -> LazyMapSequence<LazyFilterSequence<LazyMapSequence<Self.Elements, ElementOfResult?>>, ElementOfResult> Returns the non-nil results of mapping the given transformation over this sequence.
protocol RandomAccessCollection<Element> : BidirectionalCollection where Self.Indices : RandomAccessCollection, Self.SubSequence : RandomAccessCollectionA collection that supports efficient random-access index traversal.
func index(_ i: Self.Index, offsetBy distance: Int, limitedBy limit: Self.Index) -> Self.Index? Returns an index that is the specified distance from the given index, unless that distance is beyond a given limiting index.
protocol Collection<Element> : SequenceA sequence whose elements can be traversed multiple times, nondestructively, and accessed by an indexed subscript.
var count: Int { get }The number of elements in the collection.
var endIndex: Base.Index { get }var indices: LazyMapSequence<Base, Element>.Indices { get }var isEmpty: Bool { get }A Boolean value indicating whether the collection is empty.
var startIndex: Base.Index { get }subscript(bounds: Range<Base.Index>) -> LazyMapSequence<Base, Element>.SubSequence { get } subscript(position: Base.Index) -> Element { get } Accesses the element at position.
func distance(from start: LazyMapSequence<Base, Element>.Index, to end: LazyMapSequence<Base, Element>.Index) -> Int func formIndex(after i: inout LazyMapSequence<Base, Element>.Index) func index(_ i: LazyMapSequence<Base, Element>.Index, offsetBy n: Int) -> LazyMapSequence<Base, Element>.Index func index(_ i: LazyMapSequence<Base, Element>.Index, offsetBy n: Int, limitedBy limit: LazyMapSequence<Base, Element>.Index) -> LazyMapSequence<Base, Element>.Index? func index(after i: LazyMapSequence<Base, Element>.Index) -> LazyMapSequence<Base, Element>.Index func map<ElementOfResult>(_ transform: @escaping (Element) -> ElementOfResult) -> LazyMapCollection<Base, ElementOfResult> typealias Index = Base.Indextypealias Indices = Base.Indicestypealias SubSequence = LazyMapCollection<Base.SubSequence, Element>protocol LazyCollectionProtocol : Collection, LazySequenceProtocol where Self.Elements : Collectionvar count: Int { get }The number of elements in the collection.
var isEmpty: Bool { get }A Boolean value indicating whether the collection is empty.
subscript<R>(r: R) -> Self.SubSequence where R : RangeExpression, Self.Index == R.Bound { get } Accesses the contiguous subrange of the collection’s elements specified by a range expression.
subscript(x: (UnboundedRange_) -> ()) -> Self.SubSequence { get } subscript(subranges: RangeSet<Self.Index>) -> DiscontiguousSlice<Self> { get } Accesses a view of this collection with the elements at the given indices.
func distance(from start: Self.Index, to end: Self.Index) -> Int Returns the distance between two indices.
func firstIndex(of element: Self.Element) -> Self.Index? Returns the first index where the specified value appears in the collection.
func firstIndex(where predicate: (Self.Element) throws -> Bool) rethrows -> Self.Index? Returns the first index in which an element of the collection satisfies the given predicate.
func formIndex(_ i: inout Self.Index, offsetBy distance: Int) Offsets the given index by the specified distance.
func formIndex(_ i: inout Self.Index, offsetBy distance: Int, limitedBy limit: Self.Index) -> Bool Offsets the given index by the specified distance, or so that it equals the given limiting index.
func formIndex(after i: inout Self.Index) Replaces the given index with its successor.
func index(_ i: Self.Index, offsetBy distance: Int) -> Self.Index Returns an index that is the specified distance from the given index.
func index(_ i: Self.Index, offsetBy distance: Int, limitedBy limit: Self.Index) -> Self.Index? Returns an index that is the specified distance from the given index, unless that distance is beyond a given limiting index.
func indices(of element: Self.Element) -> RangeSet<Self.Index> Returns the indices of all the elements that are equal to the given element.
func indices(where predicate: (Self.Element) throws -> Bool) rethrows -> RangeSet<Self.Index> Returns the indices of all the elements that match the given predicate.
func map<T, E>(_ transform: (Self.Element) throws(E) -> T) throws(E) -> [T] where E : Error Returns an array containing the results of mapping the given closure over the sequence’s elements.
func prefix(through position: Self.Index) -> Self.SubSequence Returns a subsequence from the start of the collection through the specified position.
func prefix(upTo end: 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 generator: inout T) -> Self.Element? where T : RandomNumberGenerator Returns a random element of the collection, using the given generator as a source for randomness.
func removingSubranges(_ subranges: RangeSet<Self.Index>) -> DiscontiguousSlice<Self> Returns a collection of the elements in this collection that are not represented by the given range set.
func split(separator: Self.Element, maxSplits: Int = Int.max, omittingEmptySubsequences: Bool = true) -> [Self.SubSequence] Returns the longest possible subsequences of the collection, in order, around elements equal to the given element.
func suffix(from start: Self.Index) -> Self.SubSequence Returns a subsequence from the specified position to the end of the collection.
func index(of element: Self.Element) -> Self.Index? Returns the first index where the specified value appears in the collection.