trunk/main/src/main/java/org/apache/jsieve/ComparatorManager.java

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package org.apache.jsieve;

import org.apache.jsieve.comparators.Comparator;
import org.apache.jsieve.exception.LookupException;

/**
 * <p>Maps Comparator names to configured Comparator implementation classes.</p>
 * <h4>Thread Safety</h4>
 * <p>
 * Implementation dependent. {@link ComparatorManagerImpl} is a thread safe implementation.
 * </p>
 */
public interface ComparatorManager {
    
    /**
     * <p>Gets a comparator by name.</p>
     * 
     * @param name -
     *            The (logical) name of the Comparator
     * @return a comparator, not null
     * @throws LookupException
     */
    public Comparator getComparator(String name) throws LookupException;
    
    /**
     * Is an explicit declaration in a <code>require</code> statement
     * unnecessary for this comparator?
     * @param comparatorName not null
     * @return true when this comparator need not be declared by <core>require</code>,
     * false when any usage of this comparator must be declared in a <code>require</code> statement
     */
    public boolean isImplicitlyDeclared(final String comparatorName);
    
    /**
     * Is the comparator with the given name supported?
     * @param name not null
     * @return true when supported, false otherwise
     */
    public boolean isSupported(String name);
}