/*
 * This file is part of Petascope.
 *
 * Petascope is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * Petascope 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Petascope. If not, see <http://www.gnu.org/licenses/>.
 *
 * For more information please see <http://www.Petascope.org>
 * or contact Peter Baumann via <baumann@rasdaman.com>.
 *
 * Copyright 2009 Jacobs University Bremen, Peter Baumann.
 */

package java_cup.runtime;

/**
 * Defines the Scanner interface, which CUP uses in the default
 * implementation of <code>lr_parser.scan()</code>.  Integration
 * of scanners implementing <code>Scanner</code> is facilitated.
 */

/* *************************************************
  Interface Scanner
  
  Declares the next_token() method that should be
  implemented by scanners.  This method is typically
  called by lr_parser.scan().  End-of-file can be
  indicated either by returning
  <code>new Symbol(lr_parser.EOF_sym())</code> or
  <code>null</code>.
 ***************************************************/
public interface Scanner {
    /** Return the next token, or <code>null</code> on end-of-file. */
    public Symbol next_token() throws java.lang.Exception;
}