Package kotlinx.coroutines.flow

Flow — asynchronous cold stream of elements.

Types

AbstractFlow
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abstract class AbstractFlow<T> : Flow<T> , CancellableFlow<T>

Base class for stateful implementations of Flow. It tracks all the properties required for context preservation and throws an IllegalStateException if any of the properties are violated.

Flow
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interface Flow<out T>

An asynchronous data stream that sequentially emits values and completes normally or with an exception.

FlowCollector
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interface FlowCollector<in T>

FlowCollector is used as an intermediate or a terminal collector of the flow and represents an entity that accepts values emitted by the Flow.

MutableSharedFlow
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interface MutableSharedFlow<T> : SharedFlow<T> , FlowCollector<T>

A mutable SharedFlow that provides functions to emit values to the flow. An instance of MutableSharedFlow with the given configuration parameters can be created using MutableSharedFlow(...) constructor function.

MutableStateFlow
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interface MutableStateFlow<T> : StateFlow<T> , MutableSharedFlow<T>

A mutable StateFlow that provides a setter for value. An instance of MutableStateFlow with the given initial value can be created using MutableStateFlow(value) constructor function.

SharedFlow
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interface SharedFlow<out T> : Flow<T>

A hotFlow that shares emitted values among all its collectors in a broadcast fashion, so that all collectors get all emitted values. A shared flow is called hot because its active instance exists independently of the presence of collectors. This is opposed to a regular Flow, such as defined by the flow { ... } function, which is cold and is started separately for each collector.

SharingCommand
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enum SharingCommand : Enum<SharingCommand>

A command emitted by SharingStarted implementations to control the sharing coroutine in the shareIn and stateIn operators.

SharingStarted
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fun interface SharingStarted

A strategy for starting and stopping the sharing coroutine in shareIn and stateIn operators.

StateFlow
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interface StateFlow<out T> : SharedFlow<T>

A SharedFlow that represents a read-only state with a single updatable data value that emits updates to the value to its collectors. A state flow is a hot flow because its active instance exists independently of the presence of collectors. Its current value can be retrieved via the value property.

Functions

asFlow
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fun <T> Array<T>.asFlow(): Flow<T>
fun LongArray.asFlow(): Flow<Long>

Creates a cold flow that produces values from the given array. The flow being cold means that the array components are read every time a terminal operator is applied to the resulting flow.

fun <T> () -> T.asFlow(): Flow<T>
fun <T> suspend () -> T.asFlow(): Flow<T>

Creates a cold flow that produces a single value from the given functional type.

fun IntArray.asFlow(): Flow<Int>

Creates a cold flow that produces values from the array. The flow being cold means that the array components are read every time a terminal operator is applied to the resulting flow.

fun <T> Iterable<T>.asFlow(): Flow<T>

Creates a cold flow that produces values from the given iterable.

fun <T> Iterator<T>.asFlow(): Flow<T>

Creates a cold flow that produces values from the given iterator.

fun IntRange.asFlow(): Flow<Int>
fun LongRange.asFlow(): Flow<Long>

Creates a flow that produces values from the range.

fun <T> Sequence<T>.asFlow(): Flow<T>

Creates a cold flow that produces values from the given sequence.

fun <T> BroadcastChannel<T>.asFlow(): Flow<T>

Represents the given broadcast channel as a hot flow. Every flow collector will trigger a new broadcast channel subscription.

asSharedFlow
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fun <T> MutableSharedFlow<T>.asSharedFlow(): SharedFlow<T>

Represents this mutable shared flow as a read-only shared flow.

asStateFlow
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fun <T> MutableStateFlow<T>.asStateFlow(): StateFlow<T>

Represents this mutable state flow as a read-only state flow.

buffer
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fun <T> Flow<T>.buffer(capacity: Int = BUFFERED): Flow<T>

fun <T> Flow<T>.buffer(capacity: Int = BUFFERED, onBufferOverflow: BufferOverflow = BufferOverflow.SUSPEND): Flow<T>

Buffers flow emissions via channel of a specified capacity and runs collector in a separate coroutine.

cache
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fun <T> Flow<T>.cache(): Flow<T>
callbackFlow
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fun <T> callbackFlow(block: suspend ProducerScope<T>.() -> Unit): Flow<T>

Creates an instance of a coldFlow with elements that are sent to a SendChannel provided to the builder's block of code via ProducerScope. It allows elements to be produced by code that is running in a different context or concurrently.

cancellable
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fun <T> Flow<T>.cancellable(): Flow<T>

Returns a flow which checks cancellation status on each emission and throws the corresponding cancellation cause if flow collector was cancelled. Note that flow builder and all implementations of SharedFlow are cancellable by default.

catch
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fun <T> Flow<T>.catch(action: suspend FlowCollector<T>.(cause: Throwable) -> Unit): Flow<T>

Catches exceptions in the flow completion and calls a specified action with the caught exception. This operator is transparent to exceptions that occur in downstream flow and does not catch exceptions that are thrown to cancel the flow.

channelFlow
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fun <T> channelFlow(block: suspend ProducerScope<T>.() -> Unit): Flow<T>

Creates an instance of a coldFlow with elements that are sent to a SendChannel provided to the builder's block of code via ProducerScope. It allows elements to be produced by code that is running in a different context or concurrently. The resulting flow is cold, which means that block is called every time a terminal operator is applied to the resulting flow.

collect
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suspend fun Flow<*>.collect()

Terminal flow operator that collects the given flow but ignores all emitted values. If any exception occurs during collect or in the provided flow, this exception is rethrown from this method.

inline suspend fun <T> Flow<T>.collect(crossinline action: suspend (T) -> Unit)

Terminal flow operator that collects the given flow with a provided action. If any exception occurs during collect or in the provided flow, this exception is rethrown from this method.

inline suspend fun <T> SharedFlow<T>.collect(crossinline action: suspend (T) -> Unit): Nothing

Terminal flow operator that collects the given SharedFlow with the provided action. If any exception occurs during collect or in the provided flow, this exception is rethrown from this method.

collectIndexed
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inline suspend fun <T> Flow<T>.collectIndexed(crossinline action: suspend (index: Int, T) -> Unit)

Terminal flow operator that collects the given flow with a provided action that takes the index of an element (zero-based) and the element. If any exception occurs during collect or in the provided flow, this exception is rethrown from this method.

collectLatest
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suspend fun <T> Flow<T>.collectLatest(action: suspend (T) -> Unit)

Terminal flow operator that collects the given flow with a provided action. The crucial difference from collect is that when the original flow emits a new value then the action block for the previous value is cancelled.

combine
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inline fun <T, R> combine(vararg flows: Flow<T>, crossinline transform: suspend (Array<T>) -> R): Flow<R>
inline fun <T, R> combine(flows: Iterable<Flow<T>>, crossinline transform: suspend (Array<T>) -> R): Flow<R>
@JvmName(name = "flowCombine")
fun <T1, T2, R> Flow<T1>.combine(flow: Flow<T2>, transform: suspend (T1, T2) -> R): Flow<R>
fun <T1, T2, R> combine(flow: Flow<T1>, flow2: Flow<T2>, transform: suspend (T1, T2) -> R): Flow<R>
fun <T1, T2, T3, R> combine(flow: Flow<T1>, flow2: Flow<T2>, flow3: Flow<T3>, transform: suspend (T1, T2, T3) -> R): Flow<R>
fun <T1, T2, T3, T4, R> combine(flow: Flow<T1>, flow2: Flow<T2>, flow3: Flow<T3>, flow4: Flow<T4>, transform: suspend (T1, T2, T3, T4) -> R): Flow<R>
fun <T1, T2, T3, T4, T5, R> combine(flow: Flow<T1>, flow2: Flow<T2>, flow3: Flow<T3>, flow4: Flow<T4>, flow5: Flow<T5>, transform: suspend (T1, T2, T3, T4, T5) -> R): Flow<R>

Returns a Flow whose values are generated with transform function by combining the most recently emitted values by each flow.

combineLatest
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fun <T1, T2, R> Flow<T1>.combineLatest(other: Flow<T2>, transform: suspend (T1, T2) -> R): Flow<R>
fun <T1, T2, T3, R> Flow<T1>.combineLatest(other: Flow<T2>, other2: Flow<T3>, transform: suspend (T1, T2, T3) -> R): Flow<R>
fun <T1, T2, T3, T4, R> Flow<T1>.combineLatest(other: Flow<T2>, other2: Flow<T3>, other3: Flow<T4>, transform: suspend (T1, T2, T3, T4) -> R): Flow<R>
fun <T1, T2, T3, T4, T5, R> Flow<T1>.combineLatest(other: Flow<T2>, other2: Flow<T3>, other3: Flow<T4>, other4: Flow<T5>, transform: suspend (T1, T2, T3, T4, T5) -> R): Flow<R>
combineTransform
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inline fun <T, R> combineTransform(vararg flows: Flow<T>, crossinline transform: suspend FlowCollector<R>.(Array<T>) -> Unit): Flow<R>
inline fun <T, R> combineTransform(flows: Iterable<Flow<T>>, crossinline transform: suspend FlowCollector<R>.(Array<T>) -> Unit): Flow<R>
@JvmName(name = "flowCombineTransform")
fun <T1, T2, R> Flow<T1>.combineTransform(flow: Flow<T2>, transform: suspend FlowCollector<R>.(T1, T2) -> Unit): Flow<R>
fun <T1, T2, R> combineTransform(flow: Flow<T1>, flow2: Flow<T2>, transform: suspend FlowCollector<R>.(T1, T2) -> Unit): Flow<R>
fun <T1, T2, T3, R> combineTransform(flow: Flow<T1>, flow2: Flow<T2>, flow3: Flow<T3>, transform: suspend FlowCollector<R>.(T1, T2, T3) -> Unit): Flow<R>
fun <T1, T2, T3, T4, R> combineTransform(flow: Flow<T1>, flow2: Flow<T2>, flow3: Flow<T3>, flow4: Flow<T4>, transform: suspend FlowCollector<R>.(T1, T2, T3, T4) -> Unit): Flow<R>
fun <T1, T2, T3, T4, T5, R> combineTransform(flow: Flow<T1>, flow2: Flow<T2>, flow3: Flow<T3>, flow4: Flow<T4>, flow5: Flow<T5>, transform: suspend FlowCollector<R>.(T1, T2, T3, T4, T5) -> Unit): Flow<R>

Returns a Flow whose values are generated by transform function that process the most recently emitted values by each flow.

conflate
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fun <T> Flow<T>.conflate(): Flow<T>

Conflates flow emissions via conflated channel and runs collector in a separate coroutine. The effect of this is that emitter is never suspended due to a slow collector, but collector always gets the most recent value emitted.

consumeAsFlow
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fun <T> ReceiveChannel<T>.consumeAsFlow(): Flow<T>

Represents the given receive channel as a hot flow and consumes the channel on the first collection from this flow. The resulting flow can be collected just once and throws IllegalStateException when trying to collect it more than once.

count
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suspend fun <T> Flow<T>.count(): Int

Returns the number of elements in this flow.

suspend fun <T> Flow<T>.count(predicate: suspend (T) -> Boolean): Int

Returns the number of elements matching the given predicate.

debounce
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fun <T> Flow<T>.debounce(timeoutMillis: (T) -> Long): Flow<T>
@JvmName(name = "debounceDuration")
fun <T> Flow<T>.debounce(timeout: (T) -> Duration): Flow<T>
fun <T> Flow<T>.debounce(timeoutMillis: Long): Flow<T>
fun <T> Flow<T>.debounce(timeout: Duration): Flow<T>

Returns a flow that mirrors the original flow, but filters out values that are followed by the newer values within the given timeout. The latest value is always emitted.

distinctUntilChanged
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fun <T> Flow<T>.distinctUntilChanged(): Flow<T>

Returns flow where all subsequent repetitions of the same value are filtered out.

fun <T> Flow<T>.distinctUntilChanged(areEquivalent: (T, T) -> Boolean): Flow<T>

Returns flow where all subsequent repetitions of the same value are filtered out, when compared with each other via the provided areEquivalent function.

distinctUntilChangedBy
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fun <T, K> Flow<T>.distinctUntilChangedBy(keySelector: (T) -> K): Flow<T>

Returns flow where all subsequent repetitions of the same key are filtered out, where key is extracted with keySelector function.

drop
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fun <T> Flow<T>.drop(count: Int): Flow<T>

Returns a flow that ignores first count elements. Throws IllegalArgumentException if count is negative.

dropWhile
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fun <T> Flow<T>.dropWhile(predicate: suspend (T) -> Boolean): Flow<T>

Returns a flow containing all elements except first elements that satisfy the given predicate.

emitAll
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suspend fun <T> FlowCollector<T>.emitAll(channel: ReceiveChannel<T>)

Emits all elements from the given channel to this flow collector and cancels (consumes) the channel afterwards. If you need to iterate over the channel without consuming it, a regular for loop should be used instead.

suspend fun <T> FlowCollector<T>.emitAll(flow: Flow<T>)

Collects all the values from the given flow and emits them to the collector. It is a shorthand for flow.collect { value -> emit(value) }.

emptyFlow
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fun <T> emptyFlow(): Flow<T>

Returns an empty flow.

filter
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inline fun <T> Flow<T>.filter(crossinline predicate: suspend (T) -> Boolean): Flow<T>

Returns a flow containing only values of the original flow that match the given predicate.

filterIsInstance
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inline fun <R> Flow<*>.filterIsInstance(): Flow<R>

Returns a flow containing only values that are instances of specified type R.

filterNot
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inline fun <T> Flow<T>.filterNot(crossinline predicate: suspend (T) -> Boolean): Flow<T>

Returns a flow containing only values of the original flow that do not match the given predicate.

filterNotNull
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fun <T : Any> Flow<T?>.filterNotNull(): Flow<T>

Returns a flow containing only values of the original flow that are not null.

first
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suspend fun <T> Flow<T>.first(): T

The terminal operator that returns the first element emitted by the flow and then cancels flow's collection. Throws NoSuchElementException if the flow was empty.

suspend fun <T> Flow<T>.first(predicate: suspend (T) -> Boolean): T

The terminal operator that returns the first element emitted by the flow matching the given predicate and then cancels flow's collection. Throws NoSuchElementException if the flow has not contained elements matching the predicate.

firstOrNull
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suspend fun <T> Flow<T>.firstOrNull(): T?

The terminal operator that returns the first element emitted by the flow and then cancels flow's collection. Returns null if the flow was empty.

suspend fun <T> Flow<T>.firstOrNull(predicate: suspend (T) -> Boolean): T?

The terminal operator that returns the first element emitted by the flow matching the given predicate and then cancels flow's collection. Returns null if the flow did not contain an element matching the predicate.

flatMapConcat
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fun <T, R> Flow<T>.flatMapConcat(transform: suspend (T) -> Flow<R>): Flow<R>

Transforms elements emitted by the original flow by applying transform, that returns another flow, and then concatenating and flattening these flows.

flatMapLatest
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inline fun <T, R> Flow<T>.flatMapLatest(crossinline transform: suspend (T) -> Flow<R>): Flow<R>

Returns a flow that switches to a new flow produced by transform function every time the original flow emits a value. When the original flow emits a new value, the previous flow produced by transform block is cancelled.

flatMapMerge
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fun <T, R> Flow<T>.flatMapMerge(concurrency: Int = DEFAULT_CONCURRENCY, transform: suspend (T) -> Flow<R>): Flow<R>

Transforms elements emitted by the original flow by applying transform, that returns another flow, and then merging and flattening these flows.

flattenConcat
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fun <T> Flow<Flow<T>>.flattenConcat(): Flow<T>

Flattens the given flow of flows into a single flow in a sequential manner, without interleaving nested flows.

flattenMerge
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fun <T> Flow<Flow<T>>.flattenMerge(concurrency: Int = DEFAULT_CONCURRENCY): Flow<T>

Flattens the given flow of flows into a single flow with a concurrency limit on the number of concurrently collected flows.

flow
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fun <T> flow(block: suspend FlowCollector<T>.() -> Unit): Flow<T>

Creates a cold flow from the given suspendable block. The flow being cold means that the block is called every time a terminal operator is applied to the resulting flow.

flowOf
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fun <T> flowOf(value: T): Flow<T>

Creates a flow that produces the given value.

fun <T> flowOf(vararg elements: T): Flow<T>

Creates a flow that produces values from the specified vararg-arguments.

flowOn
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fun <T> Flow<T>.flowOn(context: CoroutineContext): Flow<T>

Changes the context where this flow is executed to the given context. This operator is composable and affects only preceding operators that do not have its own context. This operator is context preserving: contextdoes not leak into the downstream flow.

fold
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inline suspend fun <T, R> Flow<T>.fold(initial: R, crossinline operation: suspend (R, T) -> R): R

Accumulates value starting with initial value and applying operation current accumulator value and each element

getAndUpdate
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inline fun <T> MutableStateFlow<T>.getAndUpdate(function: (T) -> T): T

Updates the MutableStateFlow.value atomically using the specified function of its value, and returns its prior value.

last
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suspend fun <T> Flow<T>.last(): T

The terminal operator that returns the last element emitted by the flow.

lastOrNull
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suspend fun <T> Flow<T>.lastOrNull(): T?

The terminal operator that returns the last element emitted by the flow or null if the flow was empty.

launchIn
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fun <T> Flow<T>.launchIn(scope: CoroutineScope): Job

Terminal flow operator that launches the collection of the given flow in the scope. It is a shorthand for scope.launch { flow.collect() }.

map
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inline fun <T, R> Flow<T>.map(crossinline transform: suspend (T) -> R): Flow<R>

Returns a flow containing the results of applying the given transform function to each value of the original flow.

mapLatest
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fun <T, R> Flow<T>.mapLatest(transform: suspend (T) -> R): Flow<R>

Returns a flow that emits elements from the original flow transformed by transform function. When the original flow emits a new value, computation of the transform block for previous value is cancelled.

mapNotNull
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inline fun <T, R : Any> Flow<T>.mapNotNull(crossinline transform: suspend (T) -> R?): Flow<R>

Returns a flow that contains only non-null results of applying the given transform function to each value of the original flow.

merge
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fun <T> Iterable<Flow<T>>.merge(): Flow<T>
fun <T> merge(vararg flows: Flow<T>): Flow<T>

Merges the given flows into a single flow without preserving an order of elements. All flows are merged concurrently, without limit on the number of simultaneously collected flows.

MutableSharedFlow
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fun <T> MutableSharedFlow(replay: Int = 0, extraBufferCapacity: Int = 0, onBufferOverflow: BufferOverflow = BufferOverflow.SUSPEND): MutableSharedFlow<T>

Creates a MutableSharedFlow with the given configuration parameters.

MutableStateFlow
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fun <T> MutableStateFlow(value: T): MutableStateFlow<T>

Creates a MutableStateFlow with the given initial value.

onCompletion
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fun <T> Flow<T>.onCompletion(action: suspend FlowCollector<T>.(cause: Throwable?) -> Unit): Flow<T>

Returns a flow that invokes the given actionafter the flow is completed or cancelled, passing the cancellation exception or failure as cause parameter of action.

onEach
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fun <T> Flow<T>.onEach(action: suspend (T) -> Unit): Flow<T>

Returns a flow that invokes the given actionbefore each value of the upstream flow is emitted downstream.

onEmpty
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fun <T> Flow<T>.onEmpty(action: suspend FlowCollector<T>.() -> Unit): Flow<T>

Invokes the given action when this flow completes without emitting any elements. The receiver of the action is FlowCollector, so onEmpty can emit additional elements. For example:

onStart
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fun <T> Flow<T>.onStart(action: suspend FlowCollector<T>.() -> Unit): Flow<T>

Returns a flow that invokes the given actionbefore this flow starts to be collected.

onSubscription
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fun <T> SharedFlow<T>.onSubscription(action: suspend FlowCollector<T>.() -> Unit): SharedFlow<T>

Returns a flow that invokes the given actionafter this shared flow starts to be collected (after the subscription is registered).

produceIn
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fun <T> Flow<T>.produceIn(scope: CoroutineScope): ReceiveChannel<T>

Creates a produce coroutine that collects the given flow.

publish
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fun <T> Flow<T>.publish(): Flow<T>
fun <T> Flow<T>.publish(bufferSize: Int): Flow<T>
receiveAsFlow
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fun <T> ReceiveChannel<T>.receiveAsFlow(): Flow<T>

Represents the given receive channel as a hot flow and receives from the channel in fan-out fashion every time this flow is collected. One element will be emitted to one collector only.

reduce
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suspend fun <S, T : S> Flow<T>.reduce(operation: suspend (S, T) -> S): S

Accumulates value starting with the first element and applying operation to current accumulator value and each element. Throws NoSuchElementException if flow was empty.

replay
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fun <T> Flow<T>.replay(): Flow<T>
fun <T> Flow<T>.replay(bufferSize: Int): Flow<T>
retry
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fun <T> Flow<T>.retry(retries: Long = Long.MAX_VALUE, predicate: suspend (cause: Throwable) -> Boolean = { true }): Flow<T>

Retries collection of the given flow up to retries times when an exception that matches the given predicate occurs in the upstream flow. This operator is transparent to exceptions that occur in downstream flow and does not retry on exceptions that are thrown to cancel the flow.

retryWhen
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fun <T> Flow<T>.retryWhen(predicate: suspend FlowCollector<T>.(cause: Throwable, attempt: Long) -> Boolean): Flow<T>

Retries collection of the given flow when an exception occurs in the upstream flow and the predicate returns true. The predicate also receives an attempt number as parameter, starting from zero on the initial call. This operator is transparent to exceptions that occur in downstream flow and does not retry on exceptions that are thrown to cancel the flow.

runningFold
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fun <T, R> Flow<T>.runningFold(initial: R, operation: suspend (R, T) -> R): Flow<R>

Folds the given flow with operation, emitting every intermediate result, including initial value. Note that initial value should be immutable (or should not be mutated) as it is shared between different collectors. For example:

runningReduce
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fun <T> Flow<T>.runningReduce(operation: suspend (T, T) -> T): Flow<T>

Reduces the given flow with operation, emitting every intermediate result, including initial value. The first element is taken as initial value for operation accumulator. This operator has a sibling with initial value -- scan.

sample
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fun <T> Flow<T>.sample(periodMillis: Long): Flow<T>
fun <T> Flow<T>.sample(period: Duration): Flow<T>

Returns a flow that emits only the latest value emitted by the original flow during the given sampling period.

scan
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fun <T, R> Flow<T>.scan(initial: R, operation: suspend (R, T) -> R): Flow<R>

Folds the given flow with operation, emitting every intermediate result, including initial value. Note that initial value should be immutable (or should not be mutated) as it is shared between different collectors. For example:

scanReduce
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fun <T> Flow<T>.scanReduce(operation: suspend (T, T) -> T): Flow<T>
shareIn
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fun <T> Flow<T>.shareIn(scope: CoroutineScope, started: SharingStarted, replay: Int = 0): SharedFlow<T>

Converts a coldFlow into a hotSharedFlow that is started in the given coroutine scope, sharing emissions from a single running instance of the upstream flow with multiple downstream subscribers, and replaying a specified number of replay values to new subscribers. See the SharedFlow documentation for the general concepts of shared flows.

single
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suspend fun <T> Flow<T>.single(): T

The terminal operator that awaits for one and only one value to be emitted. Throws NoSuchElementException for empty flow and IllegalStateException for flow that contains more than one element.

singleOrNull
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suspend fun <T> Flow<T>.singleOrNull(): T?

The terminal operator that awaits for one and only one value to be emitted. Returns the single value or null, if the flow was empty or emitted more than one value.

stateIn
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suspend fun <T> Flow<T>.stateIn(scope: CoroutineScope): StateFlow<T>

Starts the upstream flow in a given scope, suspends until the first value is emitted, and returns a hotStateFlow of future emissions, sharing the most recently emitted value from this running instance of the upstream flow with multiple downstream subscribers. See the StateFlow documentation for the general concepts of state flows.

fun <T> Flow<T>.stateIn(scope: CoroutineScope, started: SharingStarted, initialValue: T): StateFlow<T>

Converts a coldFlow into a hotStateFlow that is started in the given coroutine scope, sharing the most recently emitted value from a single running instance of the upstream flow with multiple downstream subscribers. See the StateFlow documentation for the general concepts of state flows.

switchMap
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fun <T, R> Flow<T>.switchMap(transform: suspend (T) -> Flow<R>): Flow<R>
take
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fun <T> Flow<T>.take(count: Int): Flow<T>

Returns a flow that contains first count elements. When count elements are consumed, the original flow is cancelled. Throws IllegalArgumentException if count is not positive.

takeWhile
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fun <T> Flow<T>.takeWhile(predicate: suspend (T) -> Boolean): Flow<T>

Returns a flow that contains first elements satisfying the given predicate.

toCollection
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suspend fun <T, C : MutableCollection<in T>> Flow<T>.toCollection(destination: C): C

Collects given flow into a destination

toList
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suspend fun <T> Flow<T>.toList(destination: MutableList<T> = ArrayList()): List<T>

Collects given flow into a destination

toSet
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suspend fun <T> Flow<T>.toSet(destination: MutableSet<T> = LinkedHashSet()): Set<T>

Collects given flow into a destination

transform
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inline fun <T, R> Flow<T>.transform(crossinline transform: suspend FlowCollector<R>.(T) -> Unit): Flow<R>

Applies transform function to each value of the given flow.

transformLatest
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fun <T, R> Flow<T>.transformLatest(transform: suspend FlowCollector<R>.(T) -> Unit): Flow<R>

Returns a flow that produces element by transform function every time the original flow emits a value. When the original flow emits a new value, the previous transform block is cancelled, thus the name transformLatest.

transformWhile
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fun <T, R> Flow<T>.transformWhile(transform: suspend FlowCollector<R>.(T) -> Boolean): Flow<R>

Applies transform function to each value of the given flow while this function returns true.

update
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inline fun <T> MutableStateFlow<T>.update(function: (T) -> T)

Updates the MutableStateFlow.value atomically using the specified function of its value.

updateAndGet
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inline fun <T> MutableStateFlow<T>.updateAndGet(function: (T) -> T): T

Updates the MutableStateFlow.value atomically using the specified function of its value, and returns the new value.

WhileSubscribed
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fun SharingStarted.Companion.WhileSubscribed(stopTimeout: Duration = Duration.ZERO, replayExpiration: Duration = Duration.INFINITE): SharingStarted

Sharing is started when the first subscriber appears, immediately stops when the last subscriber disappears (by default), keeping the replay cache forever (by default).

withIndex
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fun <T> Flow<T>.withIndex(): Flow<IndexedValue<T>>

Returns a flow that wraps each element into IndexedValue, containing value and its index (starting from zero).

zip
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fun <T1, T2, R> Flow<T1>.zip(other: Flow<T2>, transform: suspend (T1, T2) -> R): Flow<R>

Zips values from the current flow (this) with other flow using provided transform function applied to each pair of values. The resulting flow completes as soon as one of the flows completes and cancel is called on the remaining flow.

Properties

DEFAULT_CONCURRENCY
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val DEFAULT_CONCURRENCY: Int

Default concurrency limit that is used by flattenMerge and flatMapMerge operators. It is 16 by default and can be changed on JVM using DEFAULT_CONCURRENCY_PROPERTY_NAME property.

DEFAULT_CONCURRENCY_PROPERTY_NAME
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const val DEFAULT_CONCURRENCY_PROPERTY_NAME: String

Name of the property that defines the value of DEFAULT_CONCURRENCY.