io.servicetalk.concurrent.api

Interface ScanWithMapper<T,R>

Type Parameters:

T - Type of items emitted by the Publisher this operator is applied.

R - Type of items emitted by this operator.

All Known Subinterfaces:

ScanWithLifetimeMapper<T,R>

public interface ScanWithMapper<T,R>

Provides the ability to transform (aka map) signals emitted via the Publisher.scanWith(Supplier) operator.

Method Summary

Modifier and Type	Method and Description
R	mapOnComplete() Invoked when a PublisherSource.Subscriber.onComplete() signal is received, and maps the current state into an object of type R which will be emitted downstream as PublisherSource.Subscriber.onNext(Object), followed by PublisherSource.Subscriber.onComplete().
R	mapOnError(Throwable cause) Invoked when a PublisherSource.Subscriber.onError(Throwable) signal is received, and maps the current state into an object of type R which will be emitted downstream as PublisherSource.Subscriber.onNext(Object), followed by PublisherSource.Subscriber.onComplete().
R	mapOnNext(T next) Invoked on each PublisherSource.Subscriber.onNext(Object) signal and maps from type T to type R.
boolean	mapTerminal() Invoked when a terminal signal is received and determines if an additional PublisherSource.Subscriber.onNext(Object) signal will be emitted downstream.

Method Detail

mapOnNext

@Nullable
R mapOnNext(@Nullable
                      T next)

Invoked on each PublisherSource.Subscriber.onNext(Object) signal and maps from type T to type R.

Parameters:

next - The next element emitted from PublisherSource.Subscriber.onNext(Object).

Returns:

The result of mapping next.

mapOnError

@Nullable
R mapOnError(Throwable cause)
                throws Throwable

Invoked when a PublisherSource.Subscriber.onError(Throwable) signal is received, and maps the current state into an object of type R which will be emitted downstream as PublisherSource.Subscriber.onNext(Object), followed by PublisherSource.Subscriber.onComplete().

If this method throws the exception will be propagated downstream via PublisherSource.Subscriber.onError(Throwable).

This method is only invoked if mapTerminal() returned true.

Parameters:

cause - The cause from upstream PublisherSource.Subscriber.onError(Throwable).

Returns:

An object of type R which will be emitted downstream as PublisherSource.Subscriber.onNext(Object).

Throws:

Throwable - If an exception occurs, which will be propagated downstream via PublisherSource.Subscriber.onError(Throwable).

mapOnComplete

@Nullable
R mapOnComplete()

Invoked when a PublisherSource.Subscriber.onComplete() signal is received, and maps the current state into an object of type R which will be emitted downstream as PublisherSource.Subscriber.onNext(Object), followed by PublisherSource.Subscriber.onComplete().

If this method throws the exception will be propagated downstream via PublisherSource.Subscriber.onError(Throwable).

This method is only invoked if mapTerminal() returned true.

Returns:

An object of type R which will be emitted downstream as PublisherSource.Subscriber.onNext(Object).

mapTerminal

boolean mapTerminal()

Invoked when a terminal signal is received and determines if an additional PublisherSource.Subscriber.onNext(Object) signal will be emitted downstream.

Returns:

If this method returns true then the mapOnError(Throwable) or mapOnComplete() will be invoked when their respective terminal signals are received. Otherwise neither mapOnError(Throwable) nor mapOnComplete() will be invoked and any terminal signal will be passed through directly (no mapping, no additional PublisherSource.Subscriber.onNext(Object)).