I would like to propose adding a flatMapLatest operator to AsyncSequence.
Motivation
When transforming elements of an asynchronous sequence into new asynchronous sequences, there are cases where only the results from the most recent transformation are relevant. A common example is a search-as-you-type interface where each keystroke triggers a network request. If a new request starts, the previous one becomes irrelevant and should be cancelled to save resources and avoid displaying stale data.
Proposed Solution
Add a flatMapLatest operator that transforms each element from the base AsyncSequence into a new inner AsyncSequence. When a new element is produced by the base sequence, iteration on the current inner sequence is cancelled, and iteration begins on the newly created sequence.
Example
let searchResults = searchQueries.flatMapLatest { query in
searchAPI(query)
}
for await result in searchResults {
displayResults(result) // Only latest results displayed
}
I've prepared an Evolution proposal and a prototype implementation including tests (see https://github.com/peterfriese/swift-async-algorithms/tree/flatMapLatest/statemachine)
I would like to propose adding a flatMapLatest operator to AsyncSequence.
Motivation
When transforming elements of an asynchronous sequence into new asynchronous sequences, there are cases where only the results from the most recent transformation are relevant. A common example is a search-as-you-type interface where each keystroke triggers a network request. If a new request starts, the previous one becomes irrelevant and should be cancelled to save resources and avoid displaying stale data.
Proposed Solution
Add a flatMapLatest operator that transforms each element from the base AsyncSequence into a new inner AsyncSequence. When a new element is produced by the base sequence, iteration on the current inner sequence is cancelled, and iteration begins on the newly created sequence.
Example
I've prepared an Evolution proposal and a prototype implementation including tests (see https://github.com/peterfriese/swift-async-algorithms/tree/flatMapLatest/statemachine)