/**
* Copyright 2005 JBoss Inc
*
* 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.spi;
import java.io.Externalizable;
import org.drools.rule.Declaration;
public interface Constraint
extends
RuleComponent,
Externalizable,
Cloneable {
/**
* Returns all the declarations required by the given
* constraint implementation.
*
* @return
*/
Declaration[] getRequiredDeclarations();
/**
* When a rule contains multiple logical branches, i.e., makes
* use of 'OR' CE, it is required to clone patterns and declarations
* for each logical branch. Since this is done at ReteOO build
* type, when constraints were already created, eventually
* some constraints need to update their references to the
* declarations.
*
* @param oldDecl
* @param newDecl
*/
void replaceDeclaration(Declaration oldDecl,
Declaration newDecl);
/**
* Clones the constraint
* @return
*/
public Object clone();
/**
* Returns the type of the constraint, either ALPHA, BETA or UNKNOWN
*
* @return
*/
public ConstraintType getType();
/**
* Returns true in case this constraint is a temporal constraint
*
* @return
*/
public boolean isTemporal();
/**
* An enum for Constraint Types
*/
public static enum ConstraintType {
UNKNOWN("UNKNOWN"),
ALPHA("ALPHA"),
BETA("BETA");
private String desc;
private ConstraintType( String desc ) {
this.desc = desc;
}
public String toString() {
return "ConstraintType::"+this.desc;
}
}
}