Class FedXPathIteration

java.lang.Object

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

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

org.eclipse.rdf4j.federated.evaluation.iterator.FedXPathIteration

All Implemented Interfaces:

AutoCloseable, CloseableIteration<BindingSet, QueryEvaluationException>, Iteration<BindingSet, QueryEvaluationException>

public class FedXPathIteration
extends LookAheadIteration<BindingSet, QueryEvaluationException>

A iteration to evaluate property path expressions.

See Also:

• PathIteration

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	FedXPathIteration.ValuePair

Constructor Summary

Constructors

Constructor	Description
FedXPathIteration(EvaluationStrategy strategy, StatementPattern.Scope scope, Var startVar, TupleExpr pathExpression, Var endVar, Var contextVar, long minLength, BindingSet bindings, QueryInfo queryInfo)

Method Summary

Modifier and Type	Method	Description
protected boolean	add(Set<FedXPathIteration.ValuePair> valueSet, FedXPathIteration.ValuePair vp)
protected boolean	addToQueue(Queue<FedXPathIteration.ValuePair> valueQueue2, FedXPathIteration.ValuePair vp)
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.
protected boolean	isUnbound(Var var, BindingSet bindings)

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

Constructor Details

FedXPathIteration

public FedXPathIteration(EvaluationStrategy strategy,
 StatementPattern.Scope scope,
 Var startVar,
 TupleExpr pathExpression,
 Var endVar,
 Var contextVar,
 long minLength,
 BindingSet bindings,
 QueryInfo queryInfo)
                  throws QueryEvaluationException

Throws:

QueryEvaluationException

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, QueryEvaluationException>

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.

Overrides:

handleClose in class LookAheadIteration<BindingSet, QueryEvaluationException>

Throws:

QueryEvaluationException

addToQueue

protected boolean addToQueue(Queue<FedXPathIteration.ValuePair> valueQueue2,
 FedXPathIteration.ValuePair vp)
                      throws QueryEvaluationException

Parameters:

valueQueue2 -

vp -

Throws:

QueryEvaluationException

add

protected boolean add(Set<FedXPathIteration.ValuePair> valueSet,
 FedXPathIteration.ValuePair vp)
               throws QueryEvaluationException

Parameters:

valueSet -

vp -

Throws:

QueryEvaluationException

isUnbound

protected boolean isUnbound(Var var,
 BindingSet bindings)

createAnonVar

public Var createAnonVar(String varName)