FlattenSequence
A sequence consisting of all the elements contained in each segment contained in some Base sequence.
@frozen struct FlattenSequence<Base> where Base : Sequence, Base.Element : SequenceThe elements of this view are a concatenation of the elements of each sequence in the base.
The joined method is always lazy, but does not implicitly confer laziness on algorithms applied to its result. In other words, for ordinary sequences s:
s.joined()does not create new storages.joined().map(f)maps eagerly and returns a new arrays.lazy.joined().map(f)maps lazily and returns aLazyMapSequence
Citizens in Swift
where Base:Sequence, Base.Element:SequenceConformances
protocol SequenceA type that provides sequential, iterated access to its elements.
Members
func makeIterator() -> FlattenSequence<Base>.Iterator Returns an iterator over the elements of this sequence.
struct Iterator
Features
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 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 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-inloop.func joined() -> FlattenSequence<Self> Returns the elements of this sequence of sequences, concatenated.
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 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 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 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 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 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 suffix(Int) -> [Self.Element] Returns a subsequence, up to the given maximum length, containing the final elements of the sequence.
func flatMap<ElementOfResult>((Self.Element) throws -> ElementOfResult?) rethrows -> [ElementOfResult]
Citizens in Swift
where Base:Collection, Base.Element:CollectionConformances
protocol CollectionA sequence whose elements can be traversed multiple times, nondestructively, and accessed by an indexed subscript.
Members
var endIndex: FlattenSequence<Base>.IndexThe collection’s “past the end” position.
var startIndex: FlattenSequence<Base>.IndexThe position of the first element in a non-empty collection.
subscript(FlattenSequence<Base>.Index) -> Base.Element.Element Accesses the element at
position.subscript(Range<FlattenSequence<Base>.Index>) -> Slice<FlattenCollection<Base>> func distance(from: FlattenSequence<Base>.Index, to: FlattenSequence<Base>.Index) -> Int func formIndex(inout FlattenSequence<Base>.Index, offsetBy: Int) func formIndex(inout FlattenSequence<Base>.Index, offsetBy: Int, limitedBy: FlattenSequence<Base>.Index) -> Bool func formIndex(after: inout FlattenSequence<Base>.Index) func index(FlattenSequence<Base>.Index, offsetBy: Int) -> FlattenSequence<Base>.Index func index(FlattenSequence<Base>.Index, offsetBy: Int, limitedBy: FlattenSequence<Base>.Index) -> FlattenSequence<Base>.Index? func index(after: FlattenSequence<Base>.Index) -> FlattenSequence<Base>.Index struct IndexA position in a FlattenCollection
Features
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 formIndex(inout Self.Index, offsetBy: Int) Offsets the given index by the specified distance.
func formIndex(inout Self.Index, offsetBy: Int, limitedBy: Self.Index) -> Bool Offsets the given index by the specified distance, or so that it equals the given limiting index.
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 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 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 suffix(from: Self.Index) -> Self.SubSequence Returns a subsequence from the specified position to the end of the collection.
func index(of: Self.Element) -> Self.Index? Returns the first index where the specified value appears in the collection.
Citizens in Swift
where Base:BidirectionalCollection, Base.Element:BidirectionalCollectionConformances
protocol BidirectionalCollectionA collection that supports backward as well as forward traversal.
Members
func formIndex(before: inout FlattenSequence<Base>.Index) func index(before: FlattenSequence<Base>.Index) -> FlattenSequence<Base>.Index
Features
var last: Self.Element?The last element of the collection.
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 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.