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

Class FilterNodeImpl

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.JoinOrFilterNodeImpl

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

All Implemented Interfaces:

CommutativeJoinOrFilterNode, FilterNode, JoinOrFilterNode, QueryNode, UnaryOperatorNode, Cloneable

public class FilterNodeImpl
extends JoinOrFilterNodeImpl
implements FilterNode

Field Summary

Fields inherited from class it.unibz.inf.ontop.iq.node.impl.JoinOrFilterNodeImpl

substitutionFactory, substitutionTools, termFactory, typeFactory, unificationTools

Method Summary

Modifier and Type	Method and Description
FilterNode	acceptNodeTransformer(HomogeneousQueryNodeTransformer transformer) "Accept" method for the "Visitor" pattern.
IQTree	acceptTransformer(IQTree tree, IQTreeVisitingTransformer transformer, IQTree child)
<T> T	acceptVisitor(IQVisitor<T> visitor, IQTree child)
void	acceptVisitor(QueryNodeVisitor visitor) "Accept" method for the "Visitor" pattern.
IQTree	applyDescendingSubstitution(ImmutableSubstitution<? extends VariableOrGroundTerm> descendingSubstitution, Optional<ImmutableExpression> constraint, IQTree child)
IQTree	applyDescendingSubstitutionWithoutOptimizing(ImmutableSubstitution<? extends VariableOrGroundTerm> descendingSubstitution, IQTree child)
IQTree	applyFreshRenaming(InjectiveVar2VarSubstitution renamingSubstitution, IQTree child, IQTreeCache treeCache)
FilterNode	changeFilterCondition(ImmutableExpression newFilterCondition) Returns a new FilterNode (immutable).
FilterNode	clone() See https://stackoverflow.com/questions/6837362/
ImmutableExpression	getFilterCondition() Not optional for a FilterNode.
com.google.common.collect.ImmutableSet<ImmutableSubstitution<NonVariableTerm>>	getPossibleVariableDefinitions(IQTree child)
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(IQTree child)
com.google.common.collect.ImmutableSet<com.google.common.collect.ImmutableSet<Variable>>	inferUniqueConstraints(IQTree child)
boolean	isConstructed(Variable variable, IQTree child)
boolean	isDistinct(IQTree child) TODO: detect minus encodings
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, IQTree child, VariableGenerator variableGenerator)
IQTree	normalizeForOptimization(IQTree initialChild, VariableGenerator variableGenerator, IQProperties currentIQProperties) TODO: Optimization: lift direct construction and filter nodes before normalizing them (so as to reduce the recursive pressure)
IQTree	propagateDownConstraint(ImmutableExpression constraint, IQTree child)
IQTree	removeDistincts(IQTree child, IQProperties iqProperties)
String	toString()
void	validateNode(IQTree child) Only validates the node, not its child

Methods inherited from class it.unibz.inf.ontop.iq.node.impl.JoinOrFilterNodeImpl

checkExpression, getLocallyDefinedVariables, getLocallyRequiredVariables, getLocalVariables, getNullabilityEvaluator, getOptionalFilterCondition, getOptionalFilterString, isFilteringNullValue

Methods inherited from class java.lang.Object

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

Methods inherited from interface it.unibz.inf.ontop.iq.node.JoinOrFilterNode

getOptionalFilterCondition

Methods inherited from interface it.unibz.inf.ontop.iq.node.QueryNode

getLocallyDefinedVariables, getLocallyRequiredVariables, getLocalVariables

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 FilterNode clone()

Description copied from class: QueryNodeImpl

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

Specified by:

clone in interface FilterNode

Specified by:

clone in interface QueryNode

Overrides:

clone in class QueryNodeImpl

acceptNodeTransformer

public FilterNode 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 FilterNode

Specified by:

acceptNodeTransformer in interface QueryNode

Specified by:

acceptNodeTransformer in interface UnaryOperatorNode

Throws:

QueryNodeTransformationException

getFilterCondition

public ImmutableExpression getFilterCondition()

Description copied from interface: FilterNode

Not optional for a FilterNode.

Specified by:

getFilterCondition in interface FilterNode

changeFilterCondition

public FilterNode changeFilterCondition(ImmutableExpression newFilterCondition)

Description copied from interface: FilterNode

Returns a new FilterNode (immutable).

Specified by:

changeFilterCondition in interface FilterNode

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(IQTree child)

Specified by:

getVariableNullability in interface UnaryOperatorNode

liftIncompatibleDefinitions

public IQTree liftIncompatibleDefinitions(Variable variable,
                                          IQTree child,
                                          VariableGenerator variableGenerator)

Specified by:

liftIncompatibleDefinitions in interface UnaryOperatorNode

propagateDownConstraint

public IQTree propagateDownConstraint(ImmutableExpression constraint,
                                      IQTree child)

Specified by:

propagateDownConstraint in interface UnaryOperatorNode

acceptTransformer

public IQTree acceptTransformer(IQTree tree,
                                IQTreeVisitingTransformer transformer,
                                IQTree child)

Specified by:

acceptTransformer in interface UnaryOperatorNode

acceptVisitor

public <T> T acceptVisitor(IQVisitor<T> visitor,
                           IQTree child)

Specified by:

acceptVisitor in interface UnaryOperatorNode

validateNode

public void validateNode(IQTree child)
                  throws InvalidIntermediateQueryException

Description copied from interface: UnaryOperatorNode

Only validates the node, not its child

Specified by:

validateNode in interface UnaryOperatorNode

Throws:

InvalidIntermediateQueryException

getPossibleVariableDefinitions

public com.google.common.collect.ImmutableSet<ImmutableSubstitution<NonVariableTerm>> getPossibleVariableDefinitions(IQTree child)

Specified by:

getPossibleVariableDefinitions in interface UnaryOperatorNode

removeDistincts

public IQTree removeDistincts(IQTree child,
                              IQProperties iqProperties)

Specified by:

removeDistincts in interface UnaryOperatorNode

inferUniqueConstraints

public com.google.common.collect.ImmutableSet<com.google.common.collect.ImmutableSet<Variable>> inferUniqueConstraints(IQTree child)

Specified by:

inferUniqueConstraints in interface UnaryOperatorNode

isConstructed

public boolean isConstructed(Variable variable,
                             IQTree child)

Specified by:

isConstructed in interface UnaryOperatorNode

isDistinct

public boolean isDistinct(IQTree child)

TODO: detect minus encodings

Specified by:

isDistinct in interface UnaryOperatorNode

isSyntacticallyEquivalentTo

public boolean isSyntacticallyEquivalentTo(QueryNode node)

Description copied from interface: QueryNode

TODO: explain

Specified by:

isSyntacticallyEquivalentTo in interface QueryNode

getRequiredVariables

public 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

isEquivalentTo

public boolean isEquivalentTo(QueryNode queryNode)

Description copied from interface: QueryNode

Is syntactically equivalent

Specified by:

isEquivalentTo in interface QueryNode

toString

public String toString()

Overrides:

toString in class Object

normalizeForOptimization

public IQTree normalizeForOptimization(IQTree initialChild,
                                       VariableGenerator variableGenerator,
                                       IQProperties currentIQProperties)

TODO: Optimization: lift direct construction and filter nodes before normalizing them (so as to reduce the recursive pressure)

Specified by:

normalizeForOptimization in interface UnaryOperatorNode

applyDescendingSubstitution

public IQTree applyDescendingSubstitution(ImmutableSubstitution<? extends VariableOrGroundTerm> descendingSubstitution,
                                          Optional<ImmutableExpression> constraint,
                                          IQTree child)

Specified by:

applyDescendingSubstitution in interface UnaryOperatorNode

applyDescendingSubstitutionWithoutOptimizing

public IQTree applyDescendingSubstitutionWithoutOptimizing(ImmutableSubstitution<? extends VariableOrGroundTerm> descendingSubstitution,
                                                           IQTree child)

Specified by:

applyDescendingSubstitutionWithoutOptimizing in interface UnaryOperatorNode

applyFreshRenaming

public IQTree applyFreshRenaming(InjectiveVar2VarSubstitution renamingSubstitution,
                                 IQTree child,
                                 IQTreeCache treeCache)

Specified by:

applyFreshRenaming in interface UnaryOperatorNode