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

Class ZeroLengthPathIteration

java.lang.Object

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

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

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

All Implemented Interfaces:

AutoCloseable, Iterator<BindingSet>, CloseableIteration<BindingSet>

public class ZeroLengthPathIteration
extends LookAheadIteration<BindingSet>

Field Summary

Fields

Modifier and Type	Field	Description
static final String	ANON_OBJECT_VAR
static final String	ANON_PREDICATE_VAR
static final String	ANON_SEQUENCE_VAR
static final String	ANON_SUBJECT_VAR

Constructor Summary

Constructors

Constructor	Description
ZeroLengthPathIteration(EvaluationStrategy evaluationStrategyImpl, Var subjectVar, Var objVar, Value subj, Value obj, Var contextVar, BindingSet bindings, QueryEvaluationContext context)

Method Summary

Modifier and Type	Method	Description
Var	createAnonVar(String varName)
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 org.eclipse.rdf4j.common.iteration.LookAheadIteration

hasNext, next, remove

Methods inherited from class org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration

close, isClosed

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.rdf4j.common.iteration.CloseableIteration

stream

Methods inherited from interface java.util.Iterator

forEachRemaining

Field Details

ANON_SUBJECT_VAR

public static final String ANON_SUBJECT_VAR

See Also:

• Constant Field Values

ANON_PREDICATE_VAR

public static final String ANON_PREDICATE_VAR

See Also:

• Constant Field Values

ANON_OBJECT_VAR

public static final String ANON_OBJECT_VAR

See Also:

• Constant Field Values

ANON_SEQUENCE_VAR

public static final String ANON_SEQUENCE_VAR

See Also:

• Constant Field Values

Constructor Details

ZeroLengthPathIteration

public ZeroLengthPathIteration(EvaluationStrategy evaluationStrategyImpl,
 Var subjectVar,
 Var objVar,
 Value subj,
 Value obj,
 Var contextVar,
 BindingSet bindings,
 QueryEvaluationContext context)

Method Details

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

createAnonVar

public Var createAnonVar(String varName)

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