org.apache.lucene.search.spans

Interface Spans

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 Details

doc

public int doc()
Returns the document number of the current match. Initially invalid.

end

public int end()
Returns the end position of the current match. Initially invalid.

next

public boolean next()
            throws IOException
Move to the next match, returning true iff any such exists.

skipTo

public 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.

start

public int start()
Returns the start position of the current match. Initially invalid.

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