Class LateralIterator

java.lang.Object

org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<BindingSet>

org.eclipse.rdf4j.common.iteration.LookAheadIteration<BindingSet>

org.eclipse.rdf4j.query.algebra.evaluation.iterator.LateralIterator

All Implemented Interfaces:

AutoCloseable, Iterator<BindingSet>, CloseableIteration<BindingSet>

public class LateralIterator
extends LookAheadIteration<BindingSet>

Lateral join iterator.

This iterator produces results by evaluating the right-hand side for each solution mapping from the left-hand side. Note that this is similar to a join but without any join condition.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	LateralIterator.RightEvaluator

Field Summary

Fields inherited from interface CloseableIteration

EMPTY_STATEMENT_ITERATION

Constructor Summary

Constructors

Constructor	Description
LateralIterator(QueryEvaluationStep leftPrepared, QueryEvaluationStep preparedRight, BindingSet bindings, Set<String> rightInputBindingNames)

Method Summary

Modifier and Type	Method	Description
static CloseableIteration<BindingSet>	getInstance(CloseableIteration<BindingSet> leftIter, LateralIterator.RightEvaluator rightEvaluator)
static CloseableIteration<BindingSet>	getInstance(CloseableIteration<BindingSet> leftIter, QueryEvaluationStep preparedRight, Set<String> rightInputBindingNames)
static CloseableIteration<BindingSet>	getInstance(CloseableIteration<BindingSet> leftIter, QueryEvaluationStep preparedRight, Set<String> rightInputBindingNames, BindingSet originalBindings)
static CloseableIteration<BindingSet>	getInstance(QueryEvaluationStep leftPrepared, QueryEvaluationStep preparedRight, BindingSet bindings, Set<String> rightInputBindingNames)
protected BindingSet	getNextElement()	Gets the next element.
protected void	handleClose()	Called by AbstractCloseableIteration.close() when it is called for the first time.

Methods inherited from class LookAheadIteration

hasNext, next, remove

Methods inherited from class AbstractCloseableIteration

close, isClosed

Methods inherited from class Object

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

Methods inherited from interface CloseableIteration

stream

Methods inherited from interface Iterator

forEachRemaining

Constructor Details

LateralIterator

public LateralIterator(QueryEvaluationStep leftPrepared,
 QueryEvaluationStep preparedRight,
 BindingSet bindings,
 Set<String> rightInputBindingNames)
                throws QueryEvaluationException

Throws:

QueryEvaluationException

Method Details

getInstance

public static CloseableIteration<BindingSet> getInstance(QueryEvaluationStep leftPrepared,
 QueryEvaluationStep preparedRight,
 BindingSet bindings,
 Set<String> rightInputBindingNames)

getInstance

public static CloseableIteration<BindingSet> getInstance(CloseableIteration<BindingSet> leftIter,
 QueryEvaluationStep preparedRight,
 Set<String> rightInputBindingNames)

getInstance

public static CloseableIteration<BindingSet> getInstance(CloseableIteration<BindingSet> leftIter,
 QueryEvaluationStep preparedRight,
 Set<String> rightInputBindingNames,
 BindingSet originalBindings)

getInstance

public static CloseableIteration<BindingSet> getInstance(CloseableIteration<BindingSet> leftIter,
 LateralIterator.RightEvaluator rightEvaluator)

getNextElement

protected BindingSet getNextElement()
                             throws QueryEvaluationException

Description copied from class: LookAheadIteration

Gets the next element. Subclasses should implement this method so that it returns the next element.

Specified by:

getNextElement in class LookAheadIteration<BindingSet>

Returns:

The next element, or null if no more elements are available.

Throws:

QueryEvaluationException

handleClose

protected void handleClose()
                    throws QueryEvaluationException

Description copied from class: AbstractCloseableIteration

Called by AbstractCloseableIteration.close() when it is called for the first time. This method is only called once on each iteration. By default, this method does nothing.

Specified by:

handleClose in class AbstractCloseableIteration<BindingSet>

Throws:

QueryEvaluationException