/*
 * @(#)$Id: IDREFType.java,v 1.3 2002/04/07 15:42:37 kk122374 Exp $
 *
 * Copyright 2001 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the proprietary information of Sun Microsystems, Inc.  
 * Use is subject to license terms.
 * 
 */
package com.sun.msv.datatype.xsd;

import com.sun.msv.datatype.xsd.NmtokenType;
import com.sun.msv.datatype.xsd.XSDatatypeImpl;
import com.sun.msv.datatype.xsd.DatatypeFactory;
import com.sun.msv.datatype.xsd.TypeIncubator;
import org.relaxng.datatype.ValidationContext;

/**
 * very limited 'IDREF' type of XML Schema Part 2.
 * 
 * <p>
 * The cross-reference semantics of the ID/IDREF types must be
 * implemented externally. This type by itself does not enforce such a 
 * constraint.
 * 
 * <p>
 * One can call the {@link #getIdType} method to enforce the cross-reference
 * semantics.
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class IDREFType extends NcnameType {
	
	public static final IDREFType theInstance = new IDREFType();
	
	protected IDREFType()	{ super("IDREF"); }
	
	public int getIdType() { return ID_TYPE_IDREF; }
	
	protected Object readResolve() {
		// prevent serialization from breaking the singleton.
		return theInstance;
	}
}