org.drools.core.reteoo.builder.ForallBuilder Maven / Gradle / Ivy
/*
* Copyright 2010 Red Hat, Inc. and/or its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.drools.core.reteoo.builder;
import org.drools.core.rule.Forall;
import org.drools.core.rule.GroupElement;
import org.drools.core.rule.GroupElementFactory;
import org.drools.core.rule.Pattern;
import org.drools.core.rule.RuleConditionElement;
/**
* The Reteoo component builder for forall CE
*/
public class ForallBuilder
implements
ReteooComponentBuilder {
/**
* @inheritDoc
*/
public void build(final BuildContext context,
final BuildUtils utils,
final RuleConditionElement rce) {
final Forall forall = (Forall) rce;
context.pushRuleComponent( forall );
// forall can be translated into
// not( basePattern and not( + ) )
// so we just do that:
final GroupElement and = GroupElementFactory.newAndInstance();
and.addChild( forall.getBasePattern() );
final GroupElement not2 = GroupElementFactory.newNotInstance();
not2.setForallBaseObjectType( forall.getBasePattern().getObjectType() );
if ( forall.getRemainingPatterns().size() == 1 ) {
if ( forall.isEmptyBetaConstraints() ) {
// The reason why this is here is because forall can inject a
// "this == " + BASE_IDENTIFIER $__forallBaseIdentifier
// Which we don't want to actually count in the case of forall node linking
context.setEmptyForAllBetaConstraints();
}
not2.addChild( forall.getRemainingPatterns().get( 0 ) );
and.addChild( not2 );
} else if ( forall.getRemainingPatterns().size() > 1 ) {
final GroupElement and2 = GroupElementFactory.newAndInstance();
for ( Pattern pattern : forall.getRemainingPatterns() ) {
and2.addChild( pattern );
}
not2.addChild( and2 );
and.addChild( not2 );
}
final GroupElement not = GroupElementFactory.newNotInstance();
not.addChild( and );
// get builder for the CEs
final ReteooComponentBuilder builder = utils.getBuilderFor( not );
// builds the CEs
builder.build( context,
utils,
not );
context.popRuleComponent();
}
/**
* @inheritDoc
*/
public boolean requiresLeftActivation(final BuildUtils utils,
final RuleConditionElement rce) {
return true;
}
}