org.openrdf.query.algebra
Class EmptySet

java.lang.Object
  org.openrdf.query.algebra.QueryModelNodeBase
      org.openrdf.query.algebra.EmptySet

All Implemented Interfaces:

Cloneable, QueryModelNode, TupleExpr

public class EmptySet
extends QueryModelNodeBase
implements TupleExpr

A tuple expression that contains zero solutions.

Constructor Summary

EmptySet()

Method Summary

EmptySet	clone() Returns a (deep) clone of this query model node.
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.
<X extends Exception> void	visit(QueryModelVisitor<X> visitor) Visits this node.

Methods inherited from class org.openrdf.query.algebra.QueryModelNodeBase

getParentNode, getSignature, replaceChildNode, replaceWith, setParentNode, toString, visitChildren

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.openrdf.query.algebra.QueryModelNode

getParentNode, getSignature, replaceChildNode, replaceWith, setParentNode, toString, visitChildren

Constructor Detail

EmptySet

public EmptySet()

Method Detail

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

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

Returns:

A set of binding names.

visit

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

Description copied from interface: QueryModelNode

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

Specified by:

visit in interface QueryModelNode

Throws:

X extends Exception

clone

public EmptySet 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 QueryModelNodeBase

Returns:

A deep clone of this query model node.