package org.apache.oro.text.regex;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation", "Jakarta-Oro" 
 *    must not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache" 
 *    or "Jakarta-Oro", nor may "Apache" or "Jakarta-Oro" appear in their 
 *    name, without prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * Portions of this software are based upon software originally written 
 * by Daniel F. Savarese. We appreciate his contributions.
 */

/**
 * The Pattern interface allows multiple representations of a regular
 * expression to be defined.  In general, different regular expression
 * compilers will produce different types of pattern representations.
 * Some will produce state transition tables derived from syntax trees,
 * others will produce byte code representations of an NFA, etc.  The
 * Pattern interface does not impose any specific internal pattern
 * representation, and consequently, Pattern implementations are not meant
 * to be interchangeable among differing PatternCompiler and PatternMatcher
 * implementations.  The documentation accompanying a specific implementation
 * will define what other classes a Pattern can interact with.

 @author <a href="mailto:dfs@savarese.org">Daniel F. Savarese</a>
 @version $Id: Pattern.java,v 2.1 2000/10/13 19:53:11 bwarsaw Exp $

 * @see PatternCompiler
 * @see PatternMatcher
 */
public interface Pattern {

  /**
   * This method returns the string representation of the pattern.  Its
   * purpose is to allow a pattern to be reconstructed after compilation.
   * In other words, when you compile a pattern, the resulting data 
   * structures bear no relation to the string defining the pattern.
   * It is often useful to be able to access the string defining a pattern 
   * after it has been compiled.
   * <p>
   * @return The original string representation of the regular expression
   *         pattern.
   */
  public String getPattern();



  /**
   * This method returns an integer containing the compilation options used
   * to compile this pattern.
   * <p>
   * @return The compilation options used to compile the pattern.
   */
  public int getOptions();
}
