content: package org.apache.lucene.index;
  
  /**
   * 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 java.io.Closeable;
  
  /** TermDocs provides an interface for enumerating &lt;document, frequency&gt;
   pairs for a term.  <p> The document portion names each document containing
   the term.  Documents are indicated by number.  The frequency portion gives
   the number of times the term occurred in each document.  <p> The pairs are
   ordered by document number.
  
   @see IndexReader#termDocs()
   */
  
  public interface TermDocs extends Closeable {
    /** Sets this to the data for a term.
     * The enumeration is reset to the start of the data for this term.
     */
    void seek(Term term) throws IOException;
  
    /** Sets this to the data for the current term in a {@link TermEnum}.
     * This may be optimized in some implementations.
     */
    void seek(TermEnum termEnum) throws IOException;
  
    /** Returns the current document number.  <p> This is invalid until {@link
     #next()} is called for the first time.*/
    int doc();
    
    void debug(StringBuffer buff);
  
    /** Returns the frequency of the term within the current document.  <p> This
     is invalid until {@link #next()} is called for the first time.*/
    int freq();
  
    /** Moves to the next pair in the enumeration.  <p> Returns true iff there is
     such a next pair in the enumeration. */
    boolean next() throws IOException;
  
    /** Attempts to read multiple entries from the enumeration, up to length of
     * <i>docs</i>.  Document numbers are stored in <i>docs</i>, and term
     * frequencies are stored in <i>freqs</i>.  The <i>freqs</i> array must be as
     * long as the <i>docs</i> array.
     *
     * <p>Returns the number of entries read.  Zero is only returned when the
     * stream has been exhausted.  */
    int read(int[] docs, int[] freqs) throws IOException;
  
    /** Skips entries to the first beyond the current whose document number is
     * greater than or equal to <i>target</i>. <p>Returns true iff there is such
     * an entry.  <p>Behaves as if written: <pre>
     *   boolean skipTo(int target) {
     *     do {
     *       if (!next())
     * 	     return false;
     *     } while (target > doc());
     *     return true;
     *   }
     * </pre>
     * Some implementations are considerably more efficient than that.
     */
    boolean skipTo(int target) throws IOException;
  
    /** Frees associated resources. */
    void close() throws IOException;
  }
  
  
  