Add last location memoization in Lua context

include/extractor/location_dependent_data.hpp

@@ -36,7 +36,9 @@ struct LocationDependentData
 
     bool empty() const { return rtree.empty(); }
 
-    property_t operator()(const point_t &point, const char *key) const;
+    std::vector<std::size_t> GetPropertyIndexes(const point_t &point) const;
+
+    property_t FindByKey(const std::vector<std::size_t> &property_indexes, const char *key) const;
 
   private:
     void loadLocationDependentData(const boost::filesystem::path &file_path,

include/extractor/scripting_environment_lua.hpp

@@ -22,7 +22,8 @@ namespace extractor
 struct LuaScriptingContext final
 {
     LuaScriptingContext(const LocationDependentData &location_dependent_data)
-        : location_dependent_data(location_dependent_data)
+        : location_dependent_data(location_dependent_data),
+          last_location_point(0., 180.) // assume (0,180) is invalid coordinate
     {
     }
 
@@ -52,7 +53,11 @@ struct LuaScriptingContext final
 
     int api_version;
     sol::table profile_table;
+
+    // Reference to immutable location dependent data and locations memo
     const LocationDependentData &location_dependent_data;
+    LocationDependentData::point_t last_location_point;
+    std::vector<std::size_t> last_location_indexes;
 };
 
 /**