// BSD License (http://www.galagosearch.org/license)

 package org.galagosearch.core.retrieval.structured;

 import java.io.IOException;

 import org.galagosearch.core.util.ExtentArray;

 /**

  * This is base interface for all inverted lists that return count information.

  * See the CountIterator class for documentation on most of these methods.

  * 

  * @author trevor

  */

 public abstract class ExtentIterator extends CountIterator {

     public abstract void nextDocument() throws IOException;

     public abstract int document();

     public abstract int count();

     public abstract ExtentArray extents();

     public abstract boolean isDone();

     public abstract void reset() throws IOException;

     @Override

     public boolean skipToDocument(int document) throws IOException {

         if (isDone()) {

             return false;

         }

         while (!isDone() && document() < document) {

             nextDocument();

         }

         return !isDone() && document == document();

     }

 }