A sequence containing the same elements as a Base sequence, but on which some operations such as map and filter are implemented lazily.
SDK
Framework
@frozen struct LazySequence<Base> where Base : Sequence
See also: Lazy
typealias LazyA Sequence that can contain the same elements as this one, possibly with a simpler type.
typealias LazyA type representing the sequence’s elements.
typealias LazyA type that represents a valid position in the collection.
typealias LazyA type that represents the indices that are valid for subscripting the collection, in ascending order.
typealias LazyA type that provides the collection’s iteration interface and encapsulates its iteration state.
typealias LazyA sequence that represents a contiguous subrange of the collection’s elements.
var count: IntThe number of elements in the collection.
var count: IntReturns the number of elements.
var elements: BaseThe Base (presumably non-lazy) sequence from which self was created.
var elements: LazyIdentical to self.
var endThe collection’s “past the end” position—that is, the position one greater than the last valid subscript argument.
var first: BaseThe first element of the collection.
var indices: Range<BaseThe indices that are valid for subscripting the collection, in ascending order.
var indices: DefaultThe indices that are valid for subscripting the collection, in ascending order.
var indices: BaseThe indices that are valid for subscripting the collection, in ascending order.
var isA Boolean value indicating whether the collection is empty.
var isA Boolean value indicating whether the collection is empty.
var last: BaseThe last element of the collection.
var lazy: LazyIdentical to self.
var lazy: LazyA sequence containing the same elements as this sequence, but on which some operations, such as map and filter, are implemented lazily.
var startThe position of the first element in a non-empty collection.
var underestimatedA value less than or equal to the number of elements in the sequence, calculated nondestructively.
func allReturns a Boolean value indicating whether every element of a sequence satisfies a given predicate.
func compactReturns the non-nil results of mapping the given transformation over this sequence.
func compactReturns an array containing the non-nil results of calling the given transformation with each element of this sequence.
func contains(BaseReturns a Boolean value indicating whether the sequence contains the given element.
func contains(where: (BaseReturns a Boolean value indicating whether the sequence contains an element that satisfies the given predicate.
func difference<C>(from: C) -> CollectionReturns the difference needed to produce this collection’s ordered elements from the given collection.
func difference<C>(from: C, by: (CReturns 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: LazyReturns the distance between two indices.
func drop(while: (BaseReturns a lazy sequence that skips any initial elements that satisfy predicate.
func dropReturns a sequence containing all but the given number of initial elements.
func dropReturns a subsequence containing all but the given number of initial elements.
func dropReturns a sequence containing all but the given number of final elements.
func dropReturns a subsequence containing all but the specified number of final elements.
func elementsReturns a Boolean value indicating whether this sequence and another sequence contain the same elements in the same order.
func elementsReturns 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() -> EnumeratedReturns 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((BaseReturns the elements of self that satisfy is.
func first(where: (BaseReturns the first element of the sequence that satisfies the given predicate.
func firstReturns the first index where the specified value appears in the collection.
func firstReturns the first index in which an element of the collection satisfies the given predicate.
func flatReturns the concatenated results of mapping the given transformation over this sequence.
func flatReturns the non-nil results of mapping the given transformation over this sequence.
func flatReturns an array containing the concatenated results of calling the given transformation with each element of this sequence.
func flatReturns an array containing the non-nil results of calling the given transformation with each element of this sequence.
func forCalls the given closure on each element in the sequence in the same order as a for-in loop.
func formOffsets the given index by the specified distance.
func formOffsets the given index by the specified distance, or so that it equals the given limiting index.
func formReplaces the given index with its successor.
func formReplaces the given index with its predecessor.
func index(LazyReturns an index that is the specified distance from the given index.
func index(LazyReturns an index that is the specified distance from the given index, unless that distance is beyond a given limiting index.
func index(after: LazyReturns the position immediately after the given index.
func index(before: LazyReturns the position immediately before the given index.
func index(of: BaseReturns the first index where the specified value appears in the collection.
func index(where: (BaseReturns the first index in which an element of the collection satisfies the given predicate.
func joined() -> LazyReturns a lazy sequence that concatenates the elements of this sequence of sequences.
func joined() -> FlattenReturns the elements of this sequence of sequences, concatenated.
func joined(separator: String) -> StringReturns a new string by concatenating the elements of the sequence, adding the given separator between each element.
func joined<Separator>(separator: Separator) -> JoinedReturns the concatenated elements of this sequence of sequences, inserting the given separator between each element.
func joined(separator: String) -> StringReturns a new string by concatenating the elements of the sequence, adding the given separator between each element.
func last(where: (BaseReturns the last element of the sequence that satisfies the given predicate.
func lastReturns the last index where the specified value appears in the collection.
func lastReturns the index of the last element in the collection that matches the given predicate.
func lexicographicallyReturns a Boolean value indicating whether the sequence precedes another sequence in a lexicographical (dictionary) ordering, using the less-than operator (<) to compare elements.
func lexicographicallyReturns a Boolean value indicating whether the sequence precedes another sequence in a lexicographical (dictionary) ordering, using the given predicate to compare elements.
func makeReturns an iterator over the elements of the collection.
func map<U>((BaseReturns a Lazy over this Sequence. The elements of the result are computed lazily, each time they are read, by calling transform function on a base element.
func map<T>((BaseReturns an array containing the results of mapping the given closure over the sequence’s elements.
func max() -> BaseReturns the maximum element in the sequence.
func max(by: (BaseReturns the maximum element in the sequence, using the given predicate as the comparison between elements.
func min() -> BaseReturns the minimum element in the sequence.
func min(by: (BaseReturns the minimum element in the sequence, using the given predicate as the comparison between elements.
func prefix(Int) -> PrefixReturns a sequence, up to the specified maximum length, containing the initial elements of the sequence.
func prefix(Int) -> Slice<LazyReturns a subsequence, up to the specified maximum length, containing the initial elements of the collection.
func prefix(through: BaseReturns a subsequence from the start of the collection through the specified position.
func prefix(upReturns a subsequence from the start of the collection up to, but not including, the specified position.
func prefix(while: (BaseReturns a lazy sequence of the initial consecutive elements that satisfy predicate.
func randomReturns a random element of the collection.
func randomReturns a random element of the collection, using the given generator as a source for randomness.
func reduce<Result>(Result, (Result, BaseReturns the result of combining the elements of the sequence using the given closure.
func reduce<Result>(into: Result, (inout Result, BaseReturns the result of combining the elements of the sequence using the given closure.
func reversed() -> [BaseReturns an array containing the elements of this sequence in reverse order.
func shuffled() -> [BaseReturns the elements of the sequence, shuffled.
func shuffled<T>(using: inout T) -> [BaseReturns the elements of the sequence, shuffled using the given generator as a source for randomness.
func sorted() -> [BaseReturns the elements of the sequence, sorted.
func sorted(by: (BaseReturns the elements of the sequence, sorted using the given predicate as the comparison between elements.
func split(maxReturns 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(maxReturns the longest possible subsequences of the collection, in order, that don’t contain elements satisfying the given predicate.
func split(separator: BaseReturns the longest possible subsequences of the sequence, in order, around elements equal to the given element.
func split(separator: BaseReturns the longest possible subsequences of the collection, in order, around elements equal to the given element.
func starts<PossibleReturns a Boolean value indicating whether the initial elements of the sequence are the same as the elements in another sequence.
func starts<PossibleReturns 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(Int) -> [BaseReturns a subsequence, up to the given maximum length, containing the final elements of the sequence.
func suffix(Int) -> Slice<LazyReturns a subsequence, up to the given maximum length, containing the final elements of the collection.
func suffix(from: BaseReturns a subsequence from the specified position to the end of the collection.
func withCall 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.
subscript<R>(R) -> Slice<LazyAccesses the contiguous subrange of the collection’s elements specified by a range expression.
subscript(Range<BaseAccesses a contiguous subrange of the collection’s elements.
subscript(LazyAccesses the element at position.
struct LazyA 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.
struct LazyA sequence whose elements consist of the elements of some base sequence that also satisfy a given predicate.
struct LazyA sequence whose elements consist of the initial consecutive elements of some base sequence that satisfy a given predicate.
struct LazyA sequence whose elements consist of the elements that follow the initial consecutive elements of some base sequence that satisfy a given predicate.
typealias LazyA collection containing the same elements as a Base collection, but on which some operations such as map and filter are implemented lazily.
typealias LazyA lazy wrapper that includes the elements of an underlying collection after any initial consecutive elements that satisfy a predicate.
typealias LazyA lazy Collection wrapper that includes the elements of an underlying collection that satisfy a predicate.
typealias LazyA Collection whose elements consist of those in a Base Collection 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.
typealias LazyA lazy ${Collection} wrapper that includes the initial consecutive elements of an underlying collection that satisfy a predicate.