org.deri.iris.evaluation.topdown.sldnf
Class SLDNFEvaluator

java.lang.Object
  org.deri.iris.evaluation.topdown.sldnf.SLDNFEvaluator

All Implemented Interfaces:

ITopDownEvaluator

public class SLDNFEvaluator
extends Object
implements ITopDownEvaluator

Implementation of the SLDNF evaluator. Please keep in mind that SLDNF evaluation is not capable of any tabling and can get trapped in an infinite loop. For details see 'Deduktive Datenbanken' by Cremers, Griefahn and Hinze (ISBN 978-3528047009).

Author:

gigi

Constructor Summary

SLDNFEvaluator(IFacts facts, List<IRule> rules)
Constructor

Method Summary

IRelation	evaluate(IQuery query) Evaluate given query
List<IVariable>	getOutputVariables() Return variables of the initial query

Methods inherited from class java.lang.Object

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

Constructor Detail

SLDNFEvaluator

public SLDNFEvaluator(IFacts facts,
                      List<IRule> rules)

Constructor

Parameters:

facts - one or many facts

rules - list of rules

Method Detail

evaluate

public IRelation evaluate(IQuery query)
                   throws EvaluationException

Evaluate given query

Specified by:

evaluate in interface ITopDownEvaluator

Parameters:

query - a query

Returns:

relation containing all resolved tuples.

Throws:

EvaluationException - thrown on error

getOutputVariables

public List<IVariable> getOutputVariables()

Return variables of the initial query

Specified by:

getOutputVariables in interface ITopDownEvaluator

Returns:

list of output variables