org.apache.lucene.search.spans
Interface Spans

All Known Implementing Classes:

TermSpans

public interface Spans

Expert: an enumeration of span matches. Used to implement span searching. Each span represents a range of term positions within a document. Matches are enumerated in order, by increasing document number, within that by increasing start position and finally by increasing end position.

Method Summary

int	doc() Returns the document number of the current match.
int	end() Returns the end position of the current match.
boolean	next() Move to the next match, returning true iff any such exists.
boolean	skipTo(int target) Skips to the first match beyond the current, whose document number is greater than or equal to target.
int	start() Returns the start position of the current match.

Method Detail

next

boolean next()
             throws IOException

Move to the next match, returning true iff any such exists.

Throws:

IOException

skipTo

boolean skipTo(int target)
               throws IOException

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

Returns true iff there is such a match.

Behaves as if written:

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

Most implementations are considerably more efficient than that.

Throws:

IOException

doc

int doc()

Returns the document number of the current match. Initially invalid.

start

int start()

Returns the start position of the current match. Initially invalid.

end

int end()

Returns the end position of the current match. Initially invalid.