/*
 * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package org.relaxng.datatype;

/**
 * Datatype streaming validator.
 * 
 * <p>
 * The streaming validator is an optional feature that is useful for
 * certain Datatypes. It allows the caller to incrementally provide
 * the literal.
 * 
 * @author <a href="mailto:jjc@jclark.com">James Clark</a>
 * @author <a href="mailto:kohsuke.kawaguchi@sun.com">Kohsuke KAWAGUCHI</a>
 */
public interface DatatypeStreamingValidator {
	
	/**
	 * Passes an additional fragment of the literal.
	 * 
	 * <p>
	 * The application can call this method several times, then call
	 * the isValid method (or the checkValid method) to check the validity
	 * of the accumulated characters.
	 */
	void addCharacters( char[] buf, int start, int len );
	
	/**
	 * Tells if the accumulated literal is valid with respect to
	 * the underlying Datatype.
	 * 
	 * @return
	 *		True if it is valid. False if otherwise.
	 */
	boolean isValid();
	
	/**
	 * Similar to the isValid method, but this method throws
	 * Exception (with possibly diagnostic information), instead of
	 * returning false.
	 * 
	 * @exception DatatypeException
	 *		If the callee supports the diagnosis and the accumulated
	 *		literal is invalid, then this exception that possibly
	 *		contains diagnosis information is thrown.
	 */
	void checkValid() throws DatatypeException;
}
