Class DefaultGenericQueryEvaluator<Q extends Query, QD extends QueryableData>

java.lang.Object

fr.inria.rules.integraal.query_evaluation.generic.DefaultGenericQueryEvaluator<Q,QD>

Type Parameters:

Q - the query type handled by this evaluator

QD - the queryable data type used for evaluation

All Implemented Interfaces:

QueryEvaluator<Q,QD>

public class DefaultGenericQueryEvaluator<Q extends Query, QD extends QueryableData>
extends Object
implements QueryEvaluator<Q,QD>

DefaultGenericQueryEvaluator is a default implementation of the QueryEvaluator interface. It handles the evaluation of various query types over a given FactBase.

This evaluator supports:

• First-order/Formula queries (FOQuery) using GenericFOQueryEvaluator
• Union of first-order queries (UnionFOQuery) using UnionFOQueryEvaluator

Unsupported query types will result in an IllegalArgumentException.

Constructor Summary

Constructors

Constructor	Description
DefaultGenericQueryEvaluator()	Creates the default generic query evaluator.

Method Summary

Modifier and Type	Method	Description
static DefaultGenericQueryEvaluator	defaultInstance()	The default instance is used to give a default behavior to the evaluator when one doesn't want to configure it.
Stream<Substitution>	evaluate(Q query, QD queryableData, Collection<Variable> variablesThatMustBeMappedToConstants, Substitution preHomomorphism)	Evaluates the given query over the specified fact base, applying a pre-existing substitution and ensuring that specified variables are mapped to constants.
PreparedQuery<Q, QD, Substitution, Substitution>	prepareQuery(Q query, QD queryableData, Collection<Variable> variablesThatMustBeMappedToGroundTerms)	Creates a prepared query bound to a data source and ground-term policy.

Methods inherited from class Object

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

Methods inherited from interface QueryEvaluator

countAnswers, countHomomorphism, evaluate, evaluate, existAnswer, existAnswer, existHomomorphism, existHomomorphism, homomorphism, homomorphism, postprocessResult, postprocessResult, prepareQuery

Constructor Details

DefaultGenericQueryEvaluator

public DefaultGenericQueryEvaluator()

Creates the default generic query evaluator.

Method Details

defaultInstance

public static DefaultGenericQueryEvaluator defaultInstance()

The default instance is used to give a default behavior to the evaluator when one doesn't want to configure it.

Returns:

the default instance of the evaluator

evaluate

public Stream<Substitution> evaluate(Q query,
 QD queryableData,
 Collection<Variable> variablesThatMustBeMappedToConstants,
 Substitution preHomomorphism)
                              throws EvaluationException

Evaluates the given query over the specified fact base, applying a pre-existing substitution and ensuring that specified variables are mapped to constants.

Specified by:

evaluate in interface QueryEvaluator<Q extends Query, QD extends QueryableData>

Parameters:

query - The query to evaluate.

queryableData - The fact base used for evaluation.

variablesThatMustBeMappedToConstants - A collection of variables that must be mapped to constants.

preHomomorphism - A pre-existing substitution to be applied during evaluation.

Returns:

An iterator over the resulting Substitution objects.

Throws:

IllegalArgumentException - If the query type is unsupported.

EvaluationException - if the evaluation cannot be completed

prepareQuery

public PreparedQuery<Q, QD, Substitution, Substitution> prepareQuery(Q query,
 QD queryableData,
 Collection<Variable> variablesThatMustBeMappedToGroundTerms)

Description copied from interface: QueryEvaluator

Creates a prepared query bound to a data source and ground-term policy.

Specified by:

prepareQuery in interface QueryEvaluator<Q extends Query, QD extends QueryableData>

Parameters:

query - the query to prepare

queryableData - the data source against which the query will run

variablesThatMustBeMappedToGroundTerms - variables constrained to ground answers

Returns:

a prepared query wrapper