/*
 * @(#)FunctionCluster.java
 *
 * Copyright 2004 Sun Microsystems, Inc. All Rights Reserved.
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 * specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
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package com.sun.xacml.cond.cluster;

import java.util.Set;

import com.sun.xacml.cond.Function;

/**
 * Interface used by classes that support more than one function. It's a common design model to have
 * a single class support more than one XACML function. In those cases, you should provide a proxy
 * that implements <code>FunctionCluster</code> in addition to the <code>Function</code>. This is
 * particularly important for the run-time configuration system, which uses this interface to create
 * "clusters" of functions and therefore can use a smaller configuration file.
 * 
 * @since 1.2
 * @author Seth Proctor
 */
public interface FunctionCluster {

    /**
     * Returns a single instance of each of the functions supported by some class. The
     * <code>Set</code> must contain instances of <code>Function</code>, and it must be both
     * non-null and non-empty. It may contain only a single <code>Function</code>.
     * <p>
     * Note that this is only used to return concrete <code>Function</code>s. It may not be used to
     * report abstract functions.
     * 
     * @return the functions supported by this class
     * 
     *         Adding generic type support by Christian Mueller (geotools)
     */
    public Set<Function> getSupportedFunctions();

}