content: package org.apache.lucene.search.regex;
  
  /**
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  /**
   * Defines basic operations needed by {@link RegexQuery} for a regular
   * expression implementation.
   */
  public interface RegexCapabilities {
    /**
     * Called by the constructor of {@link RegexTermEnum} allowing
     * implementations to cache a compiled version of the regular
     * expression pattern.
     *
     * @param pattern regular expression pattern
     */
    void compile(String pattern);
  
    /**
     *
     * @param string
     * @return true if string matches the pattern last passed to {@link #compile}.
     */
    boolean match(String string);
  
    /**
     * A wise prefix implementation can reduce the term enumeration (and thus increase performance)
     * of RegexQuery dramatically!
     *
     * @return static non-regex prefix of the pattern last passed to {@link #compile}.  May return null.
     */
    String prefix();
  }
  