Package org.eclipse.rdf4j.query.algebra

Class GroupElem

java.lang.Object

org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode

org.eclipse.rdf4j.query.algebra.GroupElem

All Implemented Interfaces:

Serializable, Cloneable, GraphPatternGroupable, QueryModelNode, VariableScopeChange

public class GroupElem
extends AbstractQueryModelNode

A tuple operator that groups tuples that have a specific set of equivalent variable bindings, and that can apply aggregate functions on the grouped results.

Author:

David Huynh, Arjohn Kampman

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
GroupElem(String name, AggregateOperator operator)

Method Summary

Modifier and Type	Method	Description
GroupElem	clone()	Returns a (deep) clone of this query model node.
boolean	equals(Object other)	Returns true if this query model node and its children are recursively equal to o and its children.
String	getName()
AggregateOperator	getOperator()
String	getSignature()	Default implementation of QueryModelNode.getSignature() that prints the name of the node's class.
int	hashCode()
void	replaceChildNode(QueryModelNode current, QueryModelNode replacement)	Default implementation of QueryModelNode.replaceChildNode(QueryModelNode, QueryModelNode) that throws an IllegalArgumentException indicating that current is not a child node of this node.
void	setName(String name)
void	setOperator(AggregateOperator operator)
<X extends Exception> void	visit(QueryModelVisitor<X> visitor)	Visits this node.
<X extends Exception> void	visitChildren(QueryModelVisitor<X> visitor)	Dummy implementation of QueryModelNode.visitChildren(org.eclipse.rdf4j.query.algebra.QueryModelVisitor<X>) that does nothing.

Methods inherited from class org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode

getCardinality, getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getTotalTimeNanosActual, isCardinalitySet, isGraphPatternGroup, isVariableScopeChange, nullEquals, replaceNodeInList, replaceWith, resetCardinality, setCardinality, setCostEstimate, setGraphPatternGroup, setParentNode, setResultSizeActual, setResultSizeEstimate, setTotalTimeNanosActual, setVariableScopeChange, shouldCacheCardinality, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

GroupElem

public GroupElem(String name,
 AggregateOperator operator)

Method Details

getName

public String getName()

setName

public void setName(String name)

getOperator

public AggregateOperator getOperator()

setOperator

public void setOperator(AggregateOperator operator)

visit

public <X extends Exception> void visit(QueryModelVisitor<X> visitor)
                                 throws X

Description copied from interface: QueryModelNode

Visits this node. The node reports itself to the visitor with the proper runtime type.

Throws:

X extends Exception

visitChildren

public <X extends Exception> void visitChildren(QueryModelVisitor<X> visitor)
                                         throws X

Description copied from class: AbstractQueryModelNode

Dummy implementation of QueryModelNode.visitChildren(org.eclipse.rdf4j.query.algebra.QueryModelVisitor<X>) that does nothing. Subclasses should override this method when they have child nodes.

Specified by:

visitChildren in interface QueryModelNode

Overrides:

visitChildren in class AbstractQueryModelNode

Throws:

X extends Exception

replaceChildNode

public void replaceChildNode(QueryModelNode current,
 QueryModelNode replacement)

Description copied from class: AbstractQueryModelNode

Default implementation of QueryModelNode.replaceChildNode(QueryModelNode, QueryModelNode) that throws an IllegalArgumentException indicating that current is not a child node of this node.

Specified by:

replaceChildNode in interface QueryModelNode

Overrides:

replaceChildNode in class AbstractQueryModelNode

Parameters:

current - The current child node.

replacement - The new child node.

getSignature

public String getSignature()

Description copied from class: AbstractQueryModelNode

Default implementation of QueryModelNode.getSignature() that prints the name of the node's class.

Specified by:

getSignature in interface QueryModelNode

Overrides:

getSignature in class AbstractQueryModelNode

Returns:

The node's signature, e.g. SLICE (offset=10, limit=10).

equals

public boolean equals(Object other)

Description copied from interface: QueryModelNode

Returns true if this query model node and its children are recursively equal to o and its children.

Specified by:

equals in interface QueryModelNode

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

clone

public GroupElem clone()

Description copied from interface: QueryModelNode

Returns a (deep) clone of this query model node. This method recursively clones the entire node tree, starting from this nodes.

Specified by:

clone in interface QueryModelNode

Overrides:

clone in class AbstractQueryModelNode

Returns:

A deep clone of this query model node.