package org.drools.reteoo;
/*
* $Id: HelloWorldBuilder.java,v 1.14 2005/05/08 04:22:34 dbarnett Exp $
*
* Copyright 2004-2005 (C) The Werken Company. All Rights Reserved.
*
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain copyright statements and
* notices. Redistributions must also contain a copy of this document.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. The name "drools" must not be used to endorse or promote products derived
* from this Software without prior written permission of The Werken Company.
* For written permission, please contact bob@werken.com.
*
* 4. Products derived from this Software may not be called "drools" nor may
* "drools" appear in their names without prior written permission of The Werken
* Company. "drools" is a registered trademark of The Werken Company.
*
* 5. Due credit should be given to The Werken Company.
* (http://drools.werken.com/).
*
* THIS SOFTWARE IS PROVIDED BY THE WERKEN COMPANY AND CONTRIBUTORS ``AS IS''
* AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE WERKEN COMPANY OR ITS CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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*
*/
import java.util.Iterator;
import java.util.List;
import org.drools.RuleBase;
import org.drools.rule.Declaration;
import org.drools.rule.Rule;
import org.drools.rule.RuleSet;
import org.drools.spi.Condition;
/**
* This simple Rete builder and it create a completely unoptimised Rete, ie not
* JoinNodes, but is an ideal starting point to learn more about how Rete's are
* built. org.drools.reteoo should be consultated to get a greater undertanding
* of optimisations
*/
public class HelloWorldBuilder
{
private final Rete rete;
private final Rule[] rules;
public HelloWorldBuilder(RuleSet ruleSet)
{
this.rete = new Rete( );
this.rules = ruleSet.getRules( );
}
public RuleBase buildRuleBase()
{
Declaration declaration;
Rule rule;
ParameterNode parameterNode;
for ( int i = 0; i < rules.length; i++ )
{
rule = rules[i];
for ( Iterator j = rule.getParameterDeclarations( ).iterator( ); j.hasNext( ); )
{
declaration = ( Declaration ) j.next();
parameterNode = new ParameterNode( rete.getOrCreateObjectTypeNode( declaration.getObjectType( ) ),
declaration );
parameterNode.attach( );
List conditions = rule.getConditions( );
if ( conditions.isEmpty( ) )
{
new TerminalNode( parameterNode, rule );
}
else
{
for ( int k = 0; k < conditions.size( ); k++ )
{
ConditionNode conditionNode = new ConditionNode( rule, parameterNode,
( Condition ) conditions.get( k ) );
conditionNode.attach( );
new TerminalNode( conditionNode, rule );
}
}
}
}
return new RuleBaseImpl( this.rete );
}
}