/*
 * @(#)RuleCombiningAlgorithm.java
 *
 * Copyright 2003-2005 Sun Microsystems, Inc. All Rights Reserved.
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 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
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package com.sun.xacml.combine;

import java.net.URI;
import java.util.List;

import com.sun.xacml.EvaluationCtx;
import com.sun.xacml.ctx.Result;

/**
 * The base type for all Rule combining algorithms.
 * 
 * @since 1.0
 * @author Seth Proctor
 * @author Marco Barreno
 */
public abstract class RuleCombiningAlgorithm extends CombiningAlgorithm {

    /**
     * Constructor that takes the algorithm's identifier.
     * 
     * @param identifier
     *            the algorithm's identifier
     */
    public RuleCombiningAlgorithm(URI identifier) {
        super(identifier);
    }

    /**
     * Combines the rules based on the context to produce some unified result. This is the one
     * function of a combining algorithm.
     * 
     * @param context
     *            the representation of the request
     * @param parameters
     *            a (possibly empty) non-null <code>List</code> of <code>CombinerParameter<code>s
     * @param ruleElements
     *            a <code>List</code> of <code>CombinerElement<code>s
     * 
     * @return a single unified result based on the combining logic
     */
    public abstract Result combine(EvaluationCtx context, List<CombinerParameter> parameters,
            List<? extends CombinerElement> ruleElements);

}