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/*
 * Nesting.java
 *
 * Created on March 8, 2000
 */

package com.sun.jdo.spi.persistence.support.sqlstore.query.util.scope;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * This class is used to handle the hidden definition
 * of an identifier. If an identifier is declared its old 
 * definition is hidden and stored in the actual nesting.
 *
 * @author  Michael Bouschen
 * @version 0.1
 */
public class Nesting
{
    /**
     * List of idents with hidden definitions in the actual scope.
     */
    protected List idents;
    
    /**
     * List of hidden definitions; each definition in this list
     * corresponds to an identifier of the list idents.
     */
    protected List hiddenDefs;

    /**
     * Creates an new nesting.
     */
    public Nesting()
    {
        this.idents = new ArrayList();
        this.hiddenDefs = new ArrayList();
    }

    /**
     * Adds a hidden definition to this.
     * @param ident name of the identifier
     * @param hidden the hidden definition of ident
     */
    public void add(String ident, Definition hidden)
    {
        idents.add(ident);
        hiddenDefs.add(hidden);
    }

    /**
     * Returns an enumeration of idents with hidden definitions.
     */
    public Iterator getIdents()
    {
        return idents.iterator();
    }

    /**
     * Returns an enumeration of hidden definitions.
     */
    public Iterator getHiddenDefinitions()
    {
        return hiddenDefs.iterator();
    }
}