it.unibz.inf.ontop.iq.node.impl

Class UnionNodeImpl

java.lang.Object

it.unibz.inf.ontop.iq.node.impl.QueryNodeImpl

it.unibz.inf.ontop.iq.node.impl.CompositeQueryNodeImpl

it.unibz.inf.ontop.iq.node.impl.UnionNodeImpl

All Implemented Interfaces:

ExplicitVariableProjectionNode, NaryOperatorNode, QueryNode, UnionNode, Cloneable

public class UnionNodeImpl
extends CompositeQueryNodeImpl
implements UnionNode

Method Summary

Modifier and Type	Method and Description
UnionNode	acceptNodeTransformer(HomogeneousQueryNodeTransformer transformer) "Accept" method for the "Visitor" pattern.
IQTree	acceptTransformer(IQTree tree, IQTreeVisitingTransformer transformer, it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)
<T> T	acceptVisitor(IQVisitor<T> visitor, it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)
void	acceptVisitor(QueryNodeVisitor visitor) "Accept" method for the "Visitor" pattern.
IQTree	applyDescendingSubstitution(ImmutableSubstitution<? extends VariableOrGroundTerm> descendingSubstitution, Optional<ImmutableExpression> constraint, it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)
IQTree	applyDescendingSubstitutionWithoutOptimizing(ImmutableSubstitution<? extends VariableOrGroundTerm> descendingSubstitution, it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)
IQTree	applyFreshRenaming(InjectiveVar2VarSubstitution renamingSubstitution, it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children, IQTreeCache treeCache)
UnionNode	clone() See https://stackoverflow.com/questions/6837362/
it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable>	computeNotInternallyRequiredVariables(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children) All the variables of an union could be projected out
it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable>	getLocallyDefinedVariables() Locally defined variables must not appear in the sub-tree
it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable>	getLocallyRequiredVariables() Set of variables that this node, INDEPENDENTLY OF THE REQUIREMENTS OF ITS ANCESTORS, requires to be defined in the sub-tree.
it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable>	getLocalVariables() Set of variables MENTIONED in the node, INDEPENDENTLY of its sub-tree.
it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<ImmutableSubstitution<NonVariableTerm>>	getPossibleVariableDefinitions(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)
it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable>	getRequiredVariables(IntermediateQuery query) Set of variables which, individually, must be provided by at least one child, INDEPENDENTLY OF THE REQUIREMENTS OF THIS NODE'S ANCESTORS.
VariableNullability	getVariableNullability(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)
it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable>	getVariables() Set of variables returned by any sub-tree where this node is the root.
boolean	hasAChildWithLiftableDefinition(Variable variable, it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children) Returns true if its has, as a child, a construction node defining the variable.
it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable>>	inferUniqueConstraints(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children) TODO: implement it seriously
boolean	isConstructed(Variable variable, it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)
boolean	isDistinct(IQTree tree, it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)
boolean	isEquivalentTo(QueryNode queryNode) Is syntactically equivalent
boolean	isSyntacticallyEquivalentTo(QueryNode node) TODO: explain
boolean	isVariableNullable(IntermediateQuery query, Variable variable) Returns true if it cannot guarantee the projected variable to be non-null Throws an IllegalArgumentException if the variable is not projected by the node
IQTree	liftIncompatibleDefinitions(Variable variable, it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children, VariableGenerator variableGenerator) TODO: make it compatible definitions together (requires a VariableGenerator so as to lift bindings)
IQTree	makeDistinct(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children) Makes the tree be distinct
IQTree	normalizeForOptimization(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children, VariableGenerator variableGenerator, IQProperties currentIQProperties) TODO: refactor
IQTree	propagateDownConstraint(ImmutableExpression constraint, it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)
IQTree	removeDistincts(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children, IQProperties properties)
String	toString()
void	validateNode(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children) Only validates the node, not its children

Methods inherited from class java.lang.Object

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

Method Detail

acceptVisitor

public void acceptVisitor(QueryNodeVisitor visitor)

Description copied from interface: QueryNode

"Accept" method for the "Visitor" pattern. To be implemented by leaf classes.

Specified by:

acceptVisitor in interface QueryNode

clone

public UnionNode clone()

Description copied from class: QueryNodeImpl

See https://stackoverflow.com/questions/6837362/

Specified by:

clone in interface QueryNode

Specified by:

clone in interface UnionNode

Overrides:

clone in class QueryNodeImpl

acceptNodeTransformer

public UnionNode acceptNodeTransformer(HomogeneousQueryNodeTransformer transformer)
                                throws QueryNodeTransformationException

Description copied from interface: QueryNode

"Accept" method for the "Visitor" pattern. To be implemented by leaf classes. If the transformation cannot be done, throw a QueryNodeTransformationException

Specified by:

acceptNodeTransformer in interface NaryOperatorNode

Specified by:

acceptNodeTransformer in interface QueryNode

Specified by:

acceptNodeTransformer in interface UnionNode

Throws:

QueryNodeTransformationException

getPossibleVariableDefinitions

public it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<ImmutableSubstitution<NonVariableTerm>> getPossibleVariableDefinitions(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)

Specified by:

getPossibleVariableDefinitions in interface NaryOperatorNode

hasAChildWithLiftableDefinition

public boolean hasAChildWithLiftableDefinition(Variable variable,
                                               it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)

Description copied from interface: UnionNode

Returns true if its has, as a child, a construction node defining the variable. To be called on already lifted tree.

Specified by:

hasAChildWithLiftableDefinition in interface UnionNode

isVariableNullable

public boolean isVariableNullable(IntermediateQuery query,
                                  Variable variable)

Description copied from interface: QueryNode

Returns true if it cannot guarantee the projected variable to be non-null Throws an IllegalArgumentException if the variable is not projected by the node

Specified by:

isVariableNullable in interface QueryNode

getVariableNullability

public VariableNullability getVariableNullability(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)

Specified by:

getVariableNullability in interface NaryOperatorNode

isConstructed

public boolean isConstructed(Variable variable,
                             it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)

Specified by:

isConstructed in interface NaryOperatorNode

isDistinct

public boolean isDistinct(IQTree tree,
                          it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)

Specified by:

isDistinct in interface NaryOperatorNode

makeDistinct

public IQTree makeDistinct(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)

Description copied from interface: UnionNode

Makes the tree be distinct

Specified by:

makeDistinct in interface UnionNode

liftIncompatibleDefinitions

public IQTree liftIncompatibleDefinitions(Variable variable,
                                          it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children,
                                          VariableGenerator variableGenerator)

TODO: make it compatible definitions together (requires a VariableGenerator so as to lift bindings)

Specified by:

liftIncompatibleDefinitions in interface NaryOperatorNode

propagateDownConstraint

public IQTree propagateDownConstraint(ImmutableExpression constraint,
                                      it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)

Specified by:

propagateDownConstraint in interface NaryOperatorNode

acceptTransformer

public IQTree acceptTransformer(IQTree tree,
                                IQTreeVisitingTransformer transformer,
                                it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)

Specified by:

acceptTransformer in interface NaryOperatorNode

acceptVisitor

public <T> T acceptVisitor(IQVisitor<T> visitor,
                           it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)

Specified by:

acceptVisitor in interface NaryOperatorNode

validateNode

public void validateNode(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)
                  throws InvalidIntermediateQueryException

Description copied from interface: NaryOperatorNode

Only validates the node, not its children

Specified by:

validateNode in interface NaryOperatorNode

Throws:

InvalidIntermediateQueryException

removeDistincts

public IQTree removeDistincts(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children,
                              IQProperties properties)

Specified by:

removeDistincts in interface NaryOperatorNode

inferUniqueConstraints

public it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable>> inferUniqueConstraints(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)

TODO: implement it seriously

Specified by:

inferUniqueConstraints in interface NaryOperatorNode

computeNotInternallyRequiredVariables

public it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable> computeNotInternallyRequiredVariables(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)

All the variables of an union could be projected out

Specified by:

computeNotInternallyRequiredVariables in interface NaryOperatorNode

getVariables

public it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable> getVariables()

Description copied from interface: ExplicitVariableProjectionNode

Set of variables returned by any sub-tree where this node is the root.

Specified by:

getVariables in interface ExplicitVariableProjectionNode

isSyntacticallyEquivalentTo

public boolean isSyntacticallyEquivalentTo(QueryNode node)

Description copied from interface: QueryNode

TODO: explain

Specified by:

isSyntacticallyEquivalentTo in interface QueryNode

getLocalVariables

public it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable> getLocalVariables()

Description copied from interface: QueryNode

Set of variables MENTIONED in the node, INDEPENDENTLY of its sub-tree. See ImmutableQuery.getVariables(QueryNode node) for getting all the variables returned by the QueryNode.

Specified by:

getLocalVariables in interface QueryNode

toString

public String toString()

Overrides:

toString in class Object

getLocallyRequiredVariables

public it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable> getLocallyRequiredVariables()

Description copied from interface: QueryNode

Set of variables that this node, INDEPENDENTLY OF THE REQUIREMENTS OF ITS ANCESTORS, requires to be defined in the sub-tree. Said differently, additional variable requirements may come from its ancestors.

Specified by:

getLocallyRequiredVariables in interface QueryNode

getRequiredVariables

public it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable> getRequiredVariables(IntermediateQuery query)

Description copied from interface: QueryNode

Set of variables which, individually, must be provided by at least one child, INDEPENDENTLY OF THE REQUIREMENTS OF THIS NODE'S ANCESTORS. This may extend locally required variables. For instance, for a join node, this includes variables used in implicit joining conditions

Specified by:

getRequiredVariables in interface QueryNode

getLocallyDefinedVariables

public it.unibz.inf.ontop.com.google.common.collect.ImmutableSet<Variable> getLocallyDefinedVariables()

Description copied from interface: QueryNode

Locally defined variables must not appear in the sub-tree

Specified by:

getLocallyDefinedVariables in interface QueryNode

isEquivalentTo

public boolean isEquivalentTo(QueryNode queryNode)

Description copied from interface: QueryNode

Is syntactically equivalent

Specified by:

isEquivalentTo in interface QueryNode

normalizeForOptimization

public IQTree normalizeForOptimization(it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children,
                                       VariableGenerator variableGenerator,
                                       IQProperties currentIQProperties)

TODO: refactor

Specified by:

normalizeForOptimization in interface NaryOperatorNode

applyDescendingSubstitution

public IQTree applyDescendingSubstitution(ImmutableSubstitution<? extends VariableOrGroundTerm> descendingSubstitution,
                                          Optional<ImmutableExpression> constraint,
                                          it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)

Specified by:

applyDescendingSubstitution in interface NaryOperatorNode

applyDescendingSubstitutionWithoutOptimizing

public IQTree applyDescendingSubstitutionWithoutOptimizing(ImmutableSubstitution<? extends VariableOrGroundTerm> descendingSubstitution,
                                                           it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children)

Specified by:

applyDescendingSubstitutionWithoutOptimizing in interface NaryOperatorNode

applyFreshRenaming

public IQTree applyFreshRenaming(InjectiveVar2VarSubstitution renamingSubstitution,
                                 it.unibz.inf.ontop.com.google.common.collect.ImmutableList<IQTree> children,
                                 IQTreeCache treeCache)

Specified by:

applyFreshRenaming in interface NaryOperatorNode