C# Class Lucene.Net.Search.DocIdSetIterator

this abstract class defines methods to iterate over a set of non-decreasing doc ids. Note that this class assumes it iterates on doc Ids, and therefore #NO_MORE_DOCS is set to {@value #NO_MORE_DOCS} in order to be used as a sentinel object. Implementations of this class are expected to consider Integer#MAX_VALUE as an invalid value.
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Public Methods

Method Description
Advance ( int target ) : int

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 #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 #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.

@since 2.9
Cost ( ) : long

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.
DocID ( ) : int

Returns the following:

  • -1 or #NO_MORE_DOCS if #nextDoc() or #advance(int) were not called yet.
  • #NO_MORE_DOCS if the iterator has exhausted.
  • Otherwise it should return the doc ID it is currently on.

@since 2.9
Empty ( ) : DocIdSetIterator

An empty {@code DocIdSetIterator} instance
NextDoc ( ) : int

Advances to the next document in the set and returns the doc it is currently on, or #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. @since 2.9

Protected Methods

Method Description
SlowAdvance ( int target ) : int

Slow (linear) implementation of #advance relying on #nextDoc() to advance beyond the target position.

Method Details

Advance() public abstract method

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 #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 #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.

@since 2.9

public abstract Advance ( int target ) : int
target int
return int

Cost() public abstract method

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.

public abstract Cost ( ) : long
return long

DocID() public abstract method

Returns the following:
  • -1 or #NO_MORE_DOCS if #nextDoc() or #advance(int) were not called yet.
  • #NO_MORE_DOCS if the iterator has exhausted.
  • Otherwise it should return the doc ID it is currently on.

@since 2.9

public abstract DocID ( ) : int
return int

Empty() public static method

An empty {@code DocIdSetIterator} instance
public static Empty ( ) : DocIdSetIterator
return DocIdSetIterator

NextDoc() public abstract method

Advances to the next document in the set and returns the doc it is currently on, or #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. @since 2.9
public abstract NextDoc ( ) : int
return int

SlowAdvance() protected method

Slow (linear) implementation of #advance relying on #nextDoc() to advance beyond the target position.
protected SlowAdvance ( int target ) : int
target int
return int