KeyMaker subclass which sorts by distance from a latitude/longitude. More...
Public Member Functions | |
std::string | operator() (const Xapian::Document &doc) const |
Build a key string for a Document. |
KeyMaker subclass which sorts by distance from a latitude/longitude.
Experimental - see http://xapian.org/docs/deprecation#experimental-features
Results are ordered by the distance from a fixed point, or list of points, calculated according to the metric supplied. If multiple points are supplied (either in the constructor, or in the coordinates stored in a document), the closest pointwise distance is used.
If a document contains no coordinate stored in the specified slot, a special value for the distance will be used. This defaults to a large number, so that such results get a low rank, but may be specified by a constructor parameter.
std::string Xapian::LatLongDistanceKeyMaker::operator() | ( | const Xapian::Document & | doc | ) | const [virtual] |
Build a key string for a Document.
These keys can be used for sorting or collapsing matching documents.
doc | Document object to build a key for. |
Implements Xapian::KeyMaker.