Class UnionFOQueryEvaluator<QD extends QueryableData>

java.lang.Object

fr.inria.rules.integraal.query_evaluation.union.UnionFOQueryEvaluator<QD>

Type Parameters:

QD - the queried data type

All Implemented Interfaces:

QueryEvaluator<UnionFOQuery, QD>

public class UnionFOQueryEvaluator<QD extends QueryableData>
extends Object
implements QueryEvaluator<UnionFOQuery, QD>

Evaluates a UnionFOQuery by making the union of the results;
The intersection of two substitutions is a substitution from the variables of the two substitutions An intersection is considered correct if for each variable that appear in both substitutions, the associated terms are equals

Constructor Summary

Constructors

Constructor	Description
UnionFOQueryEvaluator(FOQueryEvaluator<FOFormula, QD> evaluator)	Creates a new evaluator using the given evaluator to evaluate sub-queries

Method Summary

Modifier and Type	Method	Description
static UnionFOQueryEvaluator	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(UnionFOQuery query, QD queryableData, Collection<Variable> variablesThatMustBeMappedToConstants, Substitution preHomomorphism)	Evaluates a query against a data source.

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, prepareQuery

Constructor Details

UnionFOQueryEvaluator

public UnionFOQueryEvaluator(FOQueryEvaluator<FOFormula, QD> evaluator)

Creates a new evaluator using the given evaluator to evaluate sub-queries

Parameters:

evaluator - to evaluate sub-queries

Method Details

defaultInstance

public static UnionFOQueryEvaluator 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(UnionFOQuery query,
 QD queryableData,
 Collection<Variable> variablesThatMustBeMappedToConstants,
 Substitution preHomomorphism)
                              throws EvaluationException

Description copied from interface: QueryEvaluator

Evaluates a query against a data source.

Specified by:

evaluate in interface QueryEvaluator<UnionFOQuery, QD extends QueryableData>

Parameters:

query - query to evaluate

queryableData - queryable data source in which atoms are stored

variablesThatMustBeMappedToConstants - the set of variables that must be mapped to constants

preHomomorphism - a partial homomorphism from var(query) to terms(queryable data source) to extend

Returns:

an Stream of Substitution over all the answers of the given query in the given queryable data source with respect to the query answer variables.

Throws:

EvaluationException - if the evaluation cannot be completed