Package org.eclipse.rdf4j.query.algebra

Class Projection

java.lang.Object

org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode

org.eclipse.rdf4j.query.algebra.UnaryTupleOperator

org.eclipse.rdf4j.query.algebra.Projection

All Implemented Interfaces:

Serializable, Cloneable, GraphPatternGroupable, QueryModelNode, TupleExpr, VariableScopeChange

public class Projection
extends UnaryTupleOperator

A generalized projection (allowing the bindings to be renamed) on a tuple expression.

See Also:

• Serialized Form

Field Summary

Fields inherited from class org.eclipse.rdf4j.query.algebra.UnaryTupleOperator

arg

Constructor Summary

Constructors

Constructor	Description
Projection()
Projection(TupleExpr arg)
Projection(TupleExpr arg, ProjectionElemList elements)
Projection(TupleExpr arg, ProjectionElemList elements, boolean subquery)

Method Summary

Modifier and Type	Method	Description
Projection	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.
Set<String>	getAssuredBindingNames()	Gets the names of the bindings that are guaranteed to be present in the results produced by this tuple expression.
Set<String>	getBindingNames()	Gets the names of the bindings that are, or can be, returned by this tuple expression when it is evaluated.
Var	getProjectionContext()
ProjectionElemList	getProjectionElemList()
int	hashCode()
boolean	isSubquery()
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	setProjectionContext(Var projectionContext)
void	setProjectionElemList(ProjectionElemList projElemList)
void	setSubquery(boolean subquery)
<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.UnaryTupleOperator

getArg, setArg

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

getCardinality, getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getSignature, 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

Methods inherited from interface org.eclipse.rdf4j.query.algebra.QueryModelNode

getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getSignature, getTotalTimeNanosActual, replaceWith, setCostEstimate, setParentNode, setResultSizeActual, setResultSizeEstimate, setTotalTimeNanosActual, toString

Constructor Details

Projection

public Projection()

Projection

public Projection(TupleExpr arg)

Projection

public Projection(TupleExpr arg,
 ProjectionElemList elements)

Projection

public Projection(TupleExpr arg,
 ProjectionElemList elements,
 boolean subquery)

Method Details

getProjectionElemList

public ProjectionElemList getProjectionElemList()

setProjectionElemList

public void setProjectionElemList(ProjectionElemList projElemList)

getBindingNames

public Set<String> getBindingNames()

Description copied from interface: TupleExpr

Gets the names of the bindings that are, or can be, returned by this tuple expression when it is evaluated.

Specified by:

getBindingNames in interface TupleExpr

Overrides:

getBindingNames in class UnaryTupleOperator

Returns:

A set of binding names.

getAssuredBindingNames

public Set<String> getAssuredBindingNames()

Description copied from interface: TupleExpr

Gets the names of the bindings that are guaranteed to be present in the results produced by this tuple expression.

Specified by:

getAssuredBindingNames in interface TupleExpr

Overrides:

getAssuredBindingNames in class UnaryTupleOperator

Returns:

A set of binding names.

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

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 UnaryTupleOperator

Throws:

X

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 UnaryTupleOperator

Parameters:

current - The current child node.

replacement - The new child node.

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 UnaryTupleOperator

hashCode

public int hashCode()

Overrides:

hashCode in class UnaryTupleOperator

clone

public Projection 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

Specified by:

clone in interface TupleExpr

Overrides:

clone in class UnaryTupleOperator

Returns:

A deep clone of this query model node.

getProjectionContext

public Var getProjectionContext()

Returns:

Returns the projectionContext.

setProjectionContext

public void setProjectionContext(Var projectionContext)

Parameters:

projectionContext - The projectionContext to set.

isSubquery

public boolean isSubquery()

setSubquery

public void setSubquery(boolean subquery)