package org.apache.oro.text.regex;

/* ====================================================================
 * The Apache Software License, Version 1.1
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 * reserved.
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 * modification, are permitted provided that the following conditions
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 *    if any, must include the following acknowledgment:
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 *        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.
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 * 4. The names "Apache" and "Apache Software Foundation", "Jakarta-Oro" 
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 * 5. Products derived from this software may not be called "Apache" 
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 * 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
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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 * 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
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 * 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 1.1 2004/01/10 00:58:23 mikedemmer 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();
}