de.fuberlin.wiwiss.d2rq.engine

Class TransformFilterCNF

java.lang.Object

com.hp.hpl.jena.sparql.algebra.TransformCopy

de.fuberlin.wiwiss.d2rq.engine.TransformFilterCNF

All Implemented Interfaces:

Transform

public class TransformFilterCNF
extends TransformCopy

Checks if any OpFilter can be split into more parts by translating it to Conjunctive Normal Form (CNF).

Author:

Herwig Leimer, Richard Cyganiak (richard@cyganiak.de)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TransformFilterCNF.DeMorganLawApplyer Visitor for a filter-expression.
static class	TransformFilterCNF.DistributiveLawApplyer Visitor for a filter-expression.

Field Summary

Fields inherited from class com.hp.hpl.jena.sparql.algebra.TransformCopy

COPY_ALWAYS, COPY_ONLY_ON_CHANGE

Constructor Summary

Constructors

Constructor and Description
TransformFilterCNF()

Method Summary

Methods

Modifier and Type	Method and Description
Op	transform(OpFilter opFilter, Op subOp)
static ExprList	translateFilterExpressionsToCNF(OpFilter opFilter) Translates all expressions of a filter to the conjunctive normalform.

Methods inherited from class com.hp.hpl.jena.sparql.algebra.TransformCopy

transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform

Methods inherited from class java.lang.Object

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

Constructor Detail

TransformFilterCNF

public TransformFilterCNF()

Method Detail

transform

public Op transform(OpFilter opFilter,
           Op subOp)

Specified by:

transform in interface Transform

Overrides:

transform in class TransformCopy

translateFilterExpressionsToCNF

public static ExprList translateFilterExpressionsToCNF(OpFilter opFilter)

Translates all expressions of a filter to the conjunctive normalform. To get the conjunctive normalform of a term, first the law of DeMorgan and then the Distributive-law will be applied

Parameters:

opFilter - - a Filter with some expressions

Returns:

ExprList - every entry of the exprlist is in conjunctive normalform