# AsyncSequence Implementations ## Topics ### Instance Methods [`func allSatisfy((Self.Element) async throws -> Bool) async rethrows -> Bool`](/documentation/Swift/AsyncThrowingFlatMapSequence/allSatisfy(_:)) Returns a Boolean value that indicates whether all elements produced by the asynchronous sequence satisfy the given predicate. [`func compactMap((Self.Element) async -> ElementOfResult?) -> AsyncCompactMapSequence`](/documentation/Swift/AsyncThrowingFlatMapSequence/compactMap(_:)-4299z) 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((Self.Element) async throws -> ElementOfResult?) -> AsyncThrowingCompactMapSequence`](/documentation/Swift/AsyncThrowingFlatMapSequence/compactMap(_:)-8k2p7) 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`](/documentation/Swift/AsyncThrowingFlatMapSequence/contains(_:)) 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`](/documentation/Swift/AsyncThrowingFlatMapSequence/contains(where:)) 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`](/documentation/Swift/AsyncThrowingFlatMapSequence/drop(while:)) 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`](/documentation/Swift/AsyncThrowingFlatMapSequence/dropFirst(_:)) Omits a specified number of elements from the base asynchronous sequence, then passes through all remaining elements. [`func filter((Self.Element) async -> Bool) -> AsyncFilterSequence`](/documentation/Swift/AsyncThrowingFlatMapSequence/filter(_:)) 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?`](/documentation/Swift/AsyncThrowingFlatMapSequence/first(where:)) Returns the first element of the sequence that satisfies the given predicate. [`func flatMap((Self.Element) async -> SegmentOfResult) -> AsyncFlatMapSequence`](/documentation/Swift/AsyncThrowingFlatMapSequence/flatMap(_:)-305n4) Creates an asynchronous sequence that concatenates the results of calling the given transformation with each element of this sequence. [`func flatMap((Self.Element) async throws -> SegmentOfResult) -> AsyncThrowingFlatMapSequence`](/documentation/Swift/AsyncThrowingFlatMapSequence/flatMap(_:)-39bbv) Creates an asynchronous sequence that concatenates the results of calling the given error-throwing transformation with each element of this sequence. [`func flatMap((Self.Element) async -> SegmentOfResult) -> AsyncFlatMapSequence`](/documentation/Swift/AsyncThrowingFlatMapSequence/flatMap(_:)-6oqyf) Creates an asynchronous sequence that concatenates the results of calling the given transformation with each element of this sequence. [`func flatMap((Self.Element) async -> SegmentOfResult) -> AsyncFlatMapSequence`](/documentation/Swift/AsyncThrowingFlatMapSequence/flatMap(_:)-917rm) Creates an asynchronous sequence that concatenates the results of calling the given transformation with each element of this sequence. [`func makeAsyncIterator() -> AsyncThrowingFlatMapSequence.Iterator`](/documentation/Swift/AsyncThrowingFlatMapSequence/makeAsyncIterator()) Creates the asynchronous iterator that produces elements of this asynchronous sequence. [`func map((Self.Element) async throws -> Transformed) -> AsyncThrowingMapSequence`](/documentation/Swift/AsyncThrowingFlatMapSequence/map(_:)-81b46) Creates an asynchronous sequence that maps the given error-throwing closure over the asynchronous sequence’s elements. [`func map((Self.Element) async -> Transformed) -> AsyncMapSequence`](/documentation/Swift/AsyncThrowingFlatMapSequence/map(_:)-p3ci) Creates an asynchronous sequence that maps the given closure over the asynchronous sequence’s elements. [`func max() async rethrows -> Self.Element?`](/documentation/Swift/AsyncThrowingFlatMapSequence/max()) 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?`](/documentation/Swift/AsyncThrowingFlatMapSequence/max(by:)) Returns the maximum element in the asynchronous sequence, using the given predicate as the comparison between elements. [`func min() async rethrows -> Self.Element?`](/documentation/Swift/AsyncThrowingFlatMapSequence/min()) 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?`](/documentation/Swift/AsyncThrowingFlatMapSequence/min(by:)) Returns the minimum element in the asynchronous sequence, using the given predicate as the comparison between elements. [`func prefix(Int) -> AsyncPrefixSequence`](/documentation/Swift/AsyncThrowingFlatMapSequence/prefix(_:)) 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`](/documentation/Swift/AsyncThrowingFlatMapSequence/prefix(while:)) Returns an asynchronous sequence, containing the initial, consecutive elements of the base sequence that satisfy the given predicate. [`func reduce(Result, (Result, Self.Element) async throws -> Result) async rethrows -> Result`](/documentation/Swift/AsyncThrowingFlatMapSequence/reduce(_:_:)) Returns the result of combining the elements of the asynchronous sequence using the given closure. [`func reduce(into: Result, (inout Result, Self.Element) async throws -> Void) async rethrows -> Result`](/documentation/Swift/AsyncThrowingFlatMapSequence/reduce(into:_:)) Returns the result of combining the elements of the asynchronous sequence using the given closure, given a mutable initial value. ### Type Aliases [`typealias AsyncIterator`](/documentation/Swift/AsyncThrowingFlatMapSequence/AsyncIterator) The type of iterator that produces elements of the sequence. [`typealias Element`](/documentation/Swift/AsyncThrowingFlatMapSequence/Element) The type of element produced by this asynchronous sequence. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)