enumj

Class FilterPipeProcessor<E>

java.lang.Object

enumj.AbstractPipeProcessor<E,E>

enumj.FilterPipeProcessor<E>

Type Parameters:

E - type of enumerated elements.

final class FilterPipeProcessor<E>
extends AbstractPipeProcessor<E,E>

Pipe processor that knows how to filter elements in the pipeline.

Field Summary

Fields inherited from class enumj.AbstractPipeProcessor

hasNextNeedsValue, nextOnSameSourceOnNoValue

Constructor Summary

Constructors

Constructor and Description
FilterPipeProcessor(Predicate<E> filter) Constructs a FilterPipeProcessor instance.

Method Summary

Modifier and Type	Method and Description
protected void	clearOutputValue() Clears the processed result after being returned by AbstractPipeProcessor.retrieveOutputValue().
boolean	enqueueFilter(Predicate<E> predicate) Returns true and aggregates the given predicate to the end of existing predicates, otherwise it returns false.
boolean	hasOutputValue() Gets whether processing was successful and the processor has a value to yield.
boolean	isInactive() Gets whether the processor does not process any more and the pipeline up to it should be discarded.
void	processInputValue(E value) Processes an input value in order to return a result, if any.
boolean	pushFrontFilter(Predicate<E> predicate) Returns true and aggregates the given predicate to the top of the existing predicates, otherwise it returns false.
protected E	retrieveOutputValue() Retrieves the processed result produced by AbstractPipeProcessor.processInputValue(Object).

Methods inherited from class enumj.AbstractPipeProcessor

enqueueMap, getNext, getOutputValue, getSource, pushFrontMap, setNext, setSource

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FilterPipeProcessor

public FilterPipeProcessor(Predicate<E> filter)

Constructs a FilterPipeProcessor instance.

The new FilterPipeProcessor stores its filter internally.

Parameters:

filter - Predicate to apply on enumerated elements.

Method Detail

pushFrontFilter

public boolean pushFrontFilter(Predicate<E> predicate)

Description copied from class: AbstractPipeProcessor

Returns true and aggregates the given predicate to the top of the existing predicates, otherwise it returns false.

This method returns false by default. The only AbstractPipeProcessor capable of predicate aggregation is FilterPipeProcessor.

Overrides:

pushFrontFilter in class AbstractPipeProcessor<E,E>

Parameters:

predicate - filtering Predicate.

Returns:

true on successful aggregation of predicates, false otherwise.

enqueueFilter

public boolean enqueueFilter(Predicate<E> predicate)

Description copied from class: AbstractPipeProcessor

Returns true and aggregates the given predicate to the end of existing predicates, otherwise it returns false.

This method returns false by default. The only AbstractPipeProcessor capable of mapping aggregation is FilterPipeProcessor.

Overrides:

enqueueFilter in class AbstractPipeProcessor<E,E>

Parameters:

predicate - filtering Predicate.

Returns:

true on successful aggregation of predicates, false otherwise.

processInputValue

public void processInputValue(E value)

Description copied from class: AbstractPipeProcessor

Processes an input value in order to return a result, if any.

The result of processing must be stored internally.

Specified by:

processInputValue in class AbstractPipeProcessor<E,E>

Parameters:

value - Value to process.

See Also:

AbstractPipeProcessor.hasOutputValue(), AbstractPipeProcessor.getOutputValue()

hasOutputValue

public boolean hasOutputValue()

Description copied from class: AbstractPipeProcessor

Gets whether processing was successful and the processor has a value to yield.

If AbstractPipeProcessor.hasOutputValue() returns false than no internal storage of input or output may take place.

Specified by:

hasOutputValue in class AbstractPipeProcessor<E,E>

Returns:

true if there is an output value to yield, false otherwise.

See Also:

AbstractPipeProcessor.processInputValue(java.lang.Object), AbstractPipeProcessor.getOutputValue()

retrieveOutputValue

protected E retrieveOutputValue()

Description copied from class: AbstractPipeProcessor

Retrieves the processed result produced by AbstractPipeProcessor.processInputValue(Object).

Specified by:

retrieveOutputValue in class AbstractPipeProcessor<E,E>

Returns:

Processed result.

See Also:

AbstractPipeProcessor.getOutputValue(), AbstractPipeProcessor.clearOutputValue()

clearOutputValue

protected void clearOutputValue()

Description copied from class: AbstractPipeProcessor

Clears the processed result after being returned by AbstractPipeProcessor.retrieveOutputValue().

Specified by:

clearOutputValue in class AbstractPipeProcessor<E,E>

See Also:

AbstractPipeProcessor.getOutputValue(), AbstractPipeProcessor.retrieveOutputValue()

isInactive

public boolean isInactive()

Description copied from class: AbstractPipeProcessor

Gets whether the processor does not process any more and the pipeline up to it should be discarded.

AbstractPipeProcessor.isInactive() returning true is equivalent to the situation when no matter with what value AbstractPipeProcessor.processInputValue(Object) will be called, AbstractPipeProcessor.hasOutputValue() will always return false.

Most processors have this function return false with the exception of while and limit compositions. These will turn completely inactive once a certain condition is met.

Specified by:

isInactive in class AbstractPipeProcessor<E,E>

Returns:

true if processing must stop, false otherwise.