Structure_Concurrency5.9.0
AsyncPrefixSequence
An asynchronous sequence, up to a specified maximum length, containing the initial elements of a base asynchronous sequence.
- iOS
- 13.0+
- macOS
- 10.15+
- tvOS
- 13.0+
- watchOS
- 6.0+
struct AsyncPrefixSequence<Base> where Base : AsyncSequenceCitizens in _Concurrency
where Base:AsyncSequenceConformances
protocol AsyncSequenceA type that provides asynchronous, sequential, iterated access to its elements.
Members
func makeAsyncIterator() -> AsyncPrefixSequence<Base>.Iterator struct IteratorThe iterator that produces elements of the prefix sequence.
typealias AsyncIteratorThe type of iterator that produces elements of the sequence.
typealias ElementThe type of element produced by this asynchronous sequence.
Features
func allSatisfy((Self.Element) async throws -> Bool) async rethrows -> Bool Returns a Boolean value that indicates whether all elements produced by the asynchronous sequence satisfy the given predicate.
func compactMap<ElementOfResult>((Self.Element) async -> ElementOfResult?) -> AsyncCompactMapSequence<Self, ElementOfResult> Creates an asynchronous sequence that maps the given closure over the asynchronous sequence’s elements, omitting results that don’t return a value.
func compactMap<ElementOfResult>((Self.Element) async throws -> ElementOfResult?) -> AsyncThrowingCompactMapSequence<Self, ElementOfResult> Creates an asynchronous sequence that maps an error-throwing closure over the base sequence’s elements, omitting results that don’t return a value.
func contains(Self.Element) async rethrows -> Bool Returns a Boolean value that indicates whether the asynchronous sequence contains the given element.
func contains(where: (Self.Element) async throws -> Bool) async rethrows -> Bool Returns a Boolean value that indicates whether the asynchronous sequence contains an element that satisfies the given predicate.
func drop(while: (Self.Element) async -> Bool) -> AsyncDropWhileSequence<Self> Omits elements from the base asynchronous sequence until a given closure returns false, after which it passes through all remaining elements.
func dropFirst(Int) -> AsyncDropFirstSequence<Self> Omits a specified number of elements from the base asynchronous sequence, then passes through all remaining elements.
func filter((Self.Element) async -> Bool) -> AsyncFilterSequence<Self> Creates an asynchronous sequence that contains, in order, the elements of the base sequence that satisfy the given predicate.
func first(where: (Self.Element) async throws -> Bool) async rethrows -> Self.Element? Returns the first element of the sequence that satisfies the given predicate.
func flatMap<SegmentOfResult>((Self.Element) async throws -> SegmentOfResult) -> AsyncThrowingFlatMapSequence<Self, SegmentOfResult> Creates an asynchronous sequence that concatenates the results of calling the given error-throwing transformation with each element of this sequence.
func flatMap<SegmentOfResult>((Self.Element) async -> SegmentOfResult) -> AsyncFlatMapSequence<Self, SegmentOfResult> Creates an asynchronous sequence that concatenates the results of calling the given transformation with each element of this sequence.
func map<Transformed>((Self.Element) async -> Transformed) -> AsyncMapSequence<Self, Transformed> Creates an asynchronous sequence that maps the given closure over the asynchronous sequence’s elements.
func map<Transformed>((Self.Element) async throws -> Transformed) -> AsyncThrowingMapSequence<Self, Transformed> Creates an asynchronous sequence that maps the given error-throwing closure over the asynchronous sequence’s elements.
func max() async rethrows -> Self.Element? Returns the maximum element in an asynchronous sequence of comparable elements.
func max(by: (Self.Element, Self.Element) async throws -> Bool) async rethrows -> Self.Element? Returns the maximum element in the asynchronous sequence, using the given predicate as the comparison between elements.
func min() async rethrows -> Self.Element? Returns the minimum element in an asynchronous sequence of comparable elements.
func min(by: (Self.Element, Self.Element) async throws -> Bool) async rethrows -> Self.Element? Returns the minimum element in the asynchronous sequence, using the given predicate as the comparison between elements.
func prefix(Int) -> AsyncPrefixSequence<Self> Returns an asynchronous sequence, up to the specified maximum length, containing the initial elements of the base asynchronous sequence.
func prefix(while: (Self.Element) async -> Bool) rethrows -> AsyncPrefixWhileSequence<Self> Returns an asynchronous sequence, containing the initial, consecutive elements of the base sequence that satisfy the given predicate.
func reduce<Result>(Result, (Result, Self.Element) async throws -> Result) async rethrows -> Result Returns the result of combining the elements of the asynchronous sequence using the given closure.
func reduce<Result>(into: Result, (inout Result, Self.Element) async throws -> Void) async rethrows -> Result Returns the result of combining the elements of the asynchronous sequence using the given closure, given a mutable initial value.
Citizens in _Concurrency
where Base:Sendable, Base:AsyncSequence, Base.Element:SendableConformances
protocol SendableA type whose values can safely be passed across concurrency domains by copying.