content: package org.apache.lucene.search;
  
  /**
   * 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.
   */
  
  import java.io.IOException;
  import org.apache.lucene.index.*;
  
  /**
   * Position of a term in a document that takes into account the term offset within the phrase. 
   */
  final class PhrasePositions {
    int doc;					  // current doc
    int position;					  // position in doc
    int count;					  // remaining pos in this doc
    int offset;					  // position in phrase
    final int ord;                                  // unique across all PhrasePositions instances
    TermPositions tp;				  // stream of positions
    PhrasePositions next;				  // used to make lists
    PhrasePositions nextRepeating;	                // link to next repeating pp: standing for same term in different query offsets
  
    PhrasePositions(TermPositions t, int o, int ord) {
      tp = t;
      offset = o;
      this.ord = ord;
    }
  
    final boolean next() throws IOException {	  // increments to next doc
      if (!tp.next()) {
        tp.close();				  // close stream
        doc = Integer.MAX_VALUE;			  // sentinel value
        return false;
      }
      doc = tp.doc();
      position = 0;
      return true;
    }
  
    final boolean skipTo(int target) throws IOException {
      if (!tp.skipTo(target)) {
        tp.close();				  // close stream
        doc = Integer.MAX_VALUE;			  // sentinel value
        return false;
      }
      doc = tp.doc();
      position = 0;
      return true;
    }
  
  
    final void firstPosition() throws IOException {
      count = tp.freq();				  // read first pos
      nextPosition();
    }
  
    /**
     * Go to next location of this term current document, and set 
     * <code>position</code> as <code>location - offset</code>, so that a 
     * matching exact phrase is easily identified when all PhrasePositions 
     * have exactly the same <code>position</code>.
     */
    final boolean nextPosition() throws IOException {
      if (count-- > 0) {				  // read subsequent pos's
        position = tp.nextPosition() - offset;
        return true;
      } else
        return false;
    }
    
    /** for debug purposes */
    @Override
    public String toString() {
      String s = "d:"+doc+" o:"+offset+" p:"+position+" c:"+count;
      if (nextRepeating!=null) {
        s += " rpt[ "+nextRepeating+" ]";
      }
      return s;
    }
  }
  