Package io.servicetalk.concurrent.api

Interface ScanMapper<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:

ScanLifetimeMapper<T,R>

public interface ScanMapper<T,R>

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

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	ScanMapper.MappedTerminal<R>	Result of a mapping operation of a terminal signal.

Method Summary

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

Method Details

mapOnNext

@Nullable
R mapOnNext(@Nullable
 T next)

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

Parameters:

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

Returns:

The result of mapping next.

mapOnError

@Nullable
ScanMapper.MappedTerminal<R> mapOnError(Throwable cause)
                                 throws Throwable

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

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

Parameters:

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

Returns:

• null if no mapping is required and cause is propagated to PublisherSource.Subscriber.onError(Throwable)
• non-null will propagate ScanMapper.MappedTerminal.onNext() to PublisherSource.Subscriber.onNext(Object) then will terminate with ScanMapper.MappedTerminal.terminal()

Throws:

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

mapOnComplete

@Nullable
ScanMapper.MappedTerminal<R> mapOnComplete()
                                    throws Throwable

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

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

Returns:

• null if no mapping is required and cause is propagated to PublisherSource.Subscriber.onError(Throwable)
• non-null will propagate ScanMapper.MappedTerminal.onNext() to PublisherSource.Subscriber.onNext(Object) then will terminate with ScanMapper.MappedTerminal.terminal()

Throws:

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