org.apache.lucene.util
Class FixedBitSet.FixedBitSetIterator

java.lang.Object
  extended by org.apache.lucene.search.DocIdSetIterator
      extended by org.apache.lucene.util.FixedBitSet.FixedBitSetIterator
Enclosing class:
FixedBitSet

public static final class FixedBitSet.FixedBitSetIterator
extends DocIdSetIterator

A DocIdSetIterator which iterates over set bits in a FixedBitSet.


Field Summary
 
Fields inherited from class org.apache.lucene.search.DocIdSetIterator
NO_MORE_DOCS
 
Constructor Summary
FixedBitSet.FixedBitSetIterator(FixedBitSet bits)
          Creates an iterator over the given FixedBitSet.
FixedBitSet.FixedBitSetIterator(long[] bits, int numBits, int wordLength)
          Creates an iterator over the given array of bits.
 
Method Summary
 int advance(int target)
          Advances to the first beyond the current whose document number is greater than or equal to target, and returns the document number itself.
 long cost()
          Returns the estimated cost of this DocIdSetIterator.
 int docID()
          Returns the following: -1 or DocIdSetIterator.NO_MORE_DOCS if DocIdSetIterator.nextDoc() or DocIdSetIterator.advance(int) were not called yet.
 int nextDoc()
          Advances to the next document in the set and returns the doc it is currently on, or DocIdSetIterator.NO_MORE_DOCS if there are no more docs in the set.
NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behavior.
 
Methods inherited from class org.apache.lucene.search.DocIdSetIterator
empty, slowAdvance
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

FixedBitSet.FixedBitSetIterator

public FixedBitSet.FixedBitSetIterator(FixedBitSet bits)
Creates an iterator over the given FixedBitSet.


FixedBitSet.FixedBitSetIterator

public FixedBitSet.FixedBitSetIterator(long[] bits,
                                       int numBits,
                                       int wordLength)
Creates an iterator over the given array of bits.

Method Detail

nextDoc

public int nextDoc()
Description copied from class: DocIdSetIterator
Advances to the next document in the set and returns the doc it is currently on, or DocIdSetIterator.NO_MORE_DOCS if there are no more docs in the set.
NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behavior.

Specified by:
nextDoc in class DocIdSetIterator

docID

public int docID()
Description copied from class: DocIdSetIterator
Returns the following:

Specified by:
docID in class DocIdSetIterator

cost

public long cost()
Description copied from class: DocIdSetIterator
Returns the estimated cost of this DocIdSetIterator.

This is generally an upper bound of the number of documents this iterator might match, but may be a rough heuristic, hardcoded value, or otherwise completely inaccurate.

Specified by:
cost in class DocIdSetIterator

advance

public int advance(int target)
Description copied from class: DocIdSetIterator
Advances to the first beyond the current whose document number is greater than or equal to target, and returns the document number itself. Exhausts the iterator and returns DocIdSetIterator.NO_MORE_DOCS if target is greater than the highest document number in the set.

The behavior of this method is undefined when called with target ≤ current, or after the iterator has exhausted. Both cases may result in unpredicted behavior.

When target > current it behaves as if written:

 int advance(int target) {
   int doc;
   while ((doc = nextDoc()) < target) {
   }
   return doc;
 }
 
Some implementations are considerably more efficient than that.

NOTE: this method may be called with DocIdSetIterator.NO_MORE_DOCS for efficiency by some Scorers. If your implementation cannot efficiently determine that it should exhaust, it is recommended that you check for that value in each call to this method.

Specified by:
advance in class DocIdSetIterator


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