Module io.smallrye.mutiny

Package io.smallrye.mutiny.groups

Interface Gatherers

@Experimental("This API is still being designed and may change in the future")
public interface Gatherers

Factory interface for creating Gatherer instances.

This interface provides various static methods to create different types of gatherers.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	Gatherers.DefaultGatherer<I,ACC,O>	Default implementation of the Gatherer interface.

Method Summary

Static Methods

Modifier and Type	Method	Description
static <I> Gatherer.Builder<I>	builder()	Creates a new Gatherer builder.
static <I> Gatherer<I,I,I>	fold(Supplier<I> initialAccumulatorSupplier, BiFunction<I,I,I> accumulatorFunction)	Creates a new Gatherer that performs a fold operation.
static <I, ACC, O> Gatherer<I,ACC,O>	of(Supplier<ACC> initialAccumulatorSupplier, BiFunction<ACC,I,ACC> accumulatorFunction, BiFunction<ACC,Boolean,Optional<Gatherer.Extraction<ACC,O>>> extractor, Function<ACC,Optional<O>> finalizer)	Creates a new Gatherer with the specified components.
static <I> Gatherer<I,I,I>	scan(Supplier<I> initialAccumulatorSupplier, BiFunction<I,I,I> accumulatorFunction)	Creates a new Gatherer that performs a scan operation.
static <I> Gatherer<I,List<I>,List<I>>	slidingWindow(int size)	Creates a new Gatherer that performs a sliding window operation.
static <I> Gatherer<I,List<I>,List<I>>	window(int size)	Creates a new Gatherer that performs a windowing operation.

Method Details

of

static <I,
ACC,
O> Gatherer<I,ACC,O> of(Supplier<ACC> initialAccumulatorSupplier,
 BiFunction<ACC,I,ACC> accumulatorFunction,
 BiFunction<ACC,Boolean,Optional<Gatherer.Extraction<ACC,O>>> extractor,
 Function<ACC,Optional<O>> finalizer)

Creates a new Gatherer with the specified components.

Type Parameters:

I - the type of the items emitted by the upstream

ACC - the type of the accumulator

O - the type of the items emitted to the downstream

Parameters:

initialAccumulatorSupplier - the supplier for the initial accumulator

accumulatorFunction - the function to accumulate items into the accumulator

extractor - the function to extract items from the accumulator

finalizer - the function to extract the final item from the accumulator

Returns:

a new Gatherer

scan

static <I> Gatherer<I,I,I> scan(Supplier<I> initialAccumulatorSupplier,
 BiFunction<I,I,I> accumulatorFunction)

Creates a new Gatherer that performs a scan operation. The scan operation applies a function to each item emitted by the upstream, using the result of the previous application as the first argument to the function. The initial value is provided by the initialAccumulatorSupplier.

Each intermediate result is emitted downstream.

Type Parameters:

I - the type of the items emitted by the upstream and downstream

Parameters:

initialAccumulatorSupplier - the supplier for the initial accumulator

accumulatorFunction - the function to accumulate items

Returns:

a new Gatherer that performs a scan operation

fold

static <I> Gatherer<I,I,I> fold(Supplier<I> initialAccumulatorSupplier,
 BiFunction<I,I,I> accumulatorFunction)

Creates a new Gatherer that performs a fold operation. The fold operation applies a function to each item emitted by the upstream, using the result of the previous application as the first argument to the function. The initial value is provided by the initialAccumulatorSupplier.

Only emits the final result when the upstream completes.

Type Parameters:

I - the type of the items emitted by the upstream and downstream

Parameters:

initialAccumulatorSupplier - the supplier for the initial accumulator

accumulatorFunction - the function to accumulate items

Returns:

a new Gatherer that performs a fold operation

window

static <I> Gatherer<I,List<I>,List<I>> window(int size)

Creates a new Gatherer that performs a windowing operation. The windowing operation collects items emitted by the upstream into non-overlapping windows of the specified size. When a window is full, it is emitted downstream and a new window is started. If the upstream completes before a window is full, the current window is emitted if it is not empty.

Type Parameters:

I - the type of the items emitted by the upstream

Parameters:

size - the size of the window

Returns:

a new Gatherer that performs a windowing operation

slidingWindow

static <I> Gatherer<I,List<I>,List<I>> slidingWindow(int size)

Creates a new Gatherer that performs a sliding window operation. The sliding window operation collects items emitted by the upstream into overlapping windows of the specified size. When a window is full, it is emitted downstream and a new window is started with all but the first item from the previous window. If the upstream completes before a window is full, the current window is emitted if it is not empty.

Type Parameters:

I - the type of the items emitted by the upstream

Parameters:

size - the size of the window

Returns:

a new Gatherer that performs a sliding window operation

builder

static <I> Gatherer.Builder<I> builder()

Creates a new Gatherer builder.

Type Parameters:

I - the type of the items emitted by the upstream

Returns:

the builder