org.apache.lucene.search
Class DocIdSetIterator

java.lang.Object
  org.apache.lucene.search.DocIdSetIterator

Direct Known Subclasses:

OpenBitSetIterator, Scorer

public abstract class DocIdSetIterator
extends Object

This abstract class defines methods to iterate over a set of non-decreasing doc ids.

Constructor Summary

DocIdSetIterator()

Method Summary

abstract int	doc() Returns the current document number.
abstract boolean	next() Moves to the next docId in the set.
abstract boolean	skipTo(int target) Skips entries to the first beyond the current whose document number is greater than or equal to target.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DocIdSetIterator

public DocIdSetIterator()

Method Detail

doc

public abstract int doc()

Returns the current document number.

This is invalid until next() is called for the first time.

next

public abstract boolean next()
                      throws IOException

Moves to the next docId in the set. Returns true, iff there is such a docId.

Throws:

IOException

skipTo

public abstract boolean skipTo(int target)
                        throws IOException

Skips entries to the first beyond the current whose document number is greater than or equal to target.

Returns true iff there is such an entry.

Behaves as if written:

   boolean skipTo(int target) {
     do {
       if (!next())
         return false;
     } while (target > doc());
     return true;
   }
 

Some implementations are considerably more efficient than that.

Throws:

IOException