@parser.lookup(:location) do |name, operator, value|
        location = PreferredLocation.find_by_name(value)
        if operator == "name"
          tolerance = 1
        else
          tolerance = 0
        end
        ["((preferred_locations.lat between ? and ?) AND (preferred_locations.lon between ? and ?))", location.lat - tolerance, location.lat + tolerance, location.lon - tolerance, location.lon + tolerance]
      end
    end