Package org.eclipse.rdf4j.query.algebra
Class ZeroLengthPath
- java.lang.Object
-
- org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode
-
- org.eclipse.rdf4j.query.algebra.ZeroLengthPath
-
- All Implemented Interfaces:
Serializable
,Cloneable
,GraphPatternGroupable
,QueryModelNode
,TupleExpr
,VariableScopeChange
public class ZeroLengthPath extends AbstractQueryModelNode implements TupleExpr
A tuple expression that matches a path of length zero against an RDF graph. They can can be targeted at one of three context scopes: all contexts, null context only, or named contexts only.- See Also:
- Serialized Form
-
-
Constructor Summary
Constructors Constructor Description ZeroLengthPath()
ZeroLengthPath(StatementPattern.Scope scope, Var subject, Var object)
Creates a zero-length path that matches a subject-, predicate- and object variable against statements from the specified context scope.ZeroLengthPath(StatementPattern.Scope scope, Var subjVar, Var objVar, Var conVar)
Creates a zero-length path that matches a subject-, predicate-, object- and context variable against statements from the specified context scope.ZeroLengthPath(Var subject, Var object)
Creates a zero-length path that matches a subject-, predicate- and object variable against statements from all contexts.ZeroLengthPath(Var subject, Var object, Var context)
Creates a zero-length path that matches a subject-, predicate-, object- and context variable against statements from all contexts.
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description ZeroLengthPath
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
getContextVar()
Returns the context variable, if available.Var
getObjectVar()
StatementPattern.Scope
getScope()
Gets the context scope for the zero-length path.String
getSignature()
Default implementation ofQueryModelNode.getSignature()
that prints the name of the node's class.Var
getSubjectVar()
List<Var>
getVarList()
<L extends Collection<Var>>
LgetVars(L varCollection)
Adds the variables of this statement pattern to the supplied collection.int
hashCode()
void
replaceChildNode(QueryModelNode current, QueryModelNode replacement)
Default implementation ofQueryModelNode.replaceChildNode(QueryModelNode, QueryModelNode)
that throws anIllegalArgumentException
indicating that current is not a child node of this node.void
setContextVar(Var context)
void
setObjectVar(Var object)
void
setScope(StatementPattern.Scope scope)
Sets the context scope for the zero-length pathvoid
setSubjectVar(Var subject)
<X extends Exception>
voidvisit(QueryModelVisitor<X> visitor)
Visits this node.<X extends Exception>
voidvisitChildren(QueryModelVisitor<X> visitor)
Dummy implementation ofQueryModelNode.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
-
Methods inherited from interface org.eclipse.rdf4j.query.algebra.QueryModelNode
getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getTotalTimeNanosActual, replaceWith, setCostEstimate, setParentNode, setResultSizeActual, setResultSizeEstimate, setTotalTimeNanosActual, toString
-
-
-
-
Constructor Detail
-
ZeroLengthPath
public ZeroLengthPath()
-
ZeroLengthPath
public ZeroLengthPath(Var subject, Var object)
Creates a zero-length path that matches a subject-, predicate- and object variable against statements from all contexts.
-
ZeroLengthPath
public ZeroLengthPath(StatementPattern.Scope scope, Var subject, Var object)
Creates a zero-length path that matches a subject-, predicate- and object variable against statements from the specified context scope.
-
ZeroLengthPath
public ZeroLengthPath(Var subject, Var object, Var context)
Creates a zero-length path that matches a subject-, predicate-, object- and context variable against statements from all contexts.
-
ZeroLengthPath
public ZeroLengthPath(StatementPattern.Scope scope, Var subjVar, Var objVar, Var conVar)
Creates a zero-length path that matches a subject-, predicate-, object- and context variable against statements from the specified context scope.
-
-
Method Detail
-
getScope
public StatementPattern.Scope getScope()
Gets the context scope for the zero-length path.
-
setScope
public void setScope(StatementPattern.Scope scope)
Sets the context scope for the zero-length path
-
getSubjectVar
public Var getSubjectVar()
-
setSubjectVar
public void setSubjectVar(Var subject)
-
getObjectVar
public Var getObjectVar()
-
setObjectVar
public void setObjectVar(Var object)
-
getContextVar
public Var getContextVar()
Returns the context variable, if available.
-
setContextVar
public void setContextVar(Var context)
-
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 interfaceTupleExpr
- 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 interfaceTupleExpr
- Returns:
- A set of binding names.
-
getVars
public <L extends Collection<Var>> L getVars(L varCollection)
Adds the variables of this statement pattern to the supplied collection.
-
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 interfaceQueryModelNode
- Throws:
X extends Exception
-
visitChildren
public <X extends Exception> void visitChildren(QueryModelVisitor<X> visitor) throws X extends Exception
Description copied from class:AbstractQueryModelNode
Dummy implementation ofQueryModelNode.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 interfaceQueryModelNode
- Overrides:
visitChildren
in classAbstractQueryModelNode
- Throws:
X extends Exception
-
replaceChildNode
public void replaceChildNode(QueryModelNode current, QueryModelNode replacement)
Description copied from class:AbstractQueryModelNode
Default implementation ofQueryModelNode.replaceChildNode(QueryModelNode, QueryModelNode)
that throws anIllegalArgumentException
indicating that current is not a child node of this node.- Specified by:
replaceChildNode
in interfaceQueryModelNode
- Overrides:
replaceChildNode
in classAbstractQueryModelNode
- Parameters:
current
- The current child node.replacement
- The new child node.
-
getSignature
public String getSignature()
Description copied from class:AbstractQueryModelNode
Default implementation ofQueryModelNode.getSignature()
that prints the name of the node's class.- Specified by:
getSignature
in interfaceQueryModelNode
- Overrides:
getSignature
in classAbstractQueryModelNode
- 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 interfaceQueryModelNode
- Overrides:
equals
in classObject
-
clone
public ZeroLengthPath 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 interfaceQueryModelNode
- Specified by:
clone
in interfaceTupleExpr
- Overrides:
clone
in classAbstractQueryModelNode
- Returns:
- A deep clone of this query model node.
-
-