Make Results derived from List use its LinkViewRef

There are some advantages for the `Results` being built from a `LinkViewRef`, and the object store very much encourages that with its `filter` and `sort` methods on List.

src/js_results.hpp

@@ -38,10 +38,9 @@ struct ResultsClass : ClassDefinition<T, realm::Results, CollectionClass<T>> {
     using Value = js::Value<T>;
     using ReturnValue = js::ReturnValue<T>;
 
-    static ObjectType create_instance(ContextType, const realm::Results &, bool live = true);
+    static ObjectType create_instance(ContextType, realm::Results, bool live = true);
     static ObjectType create_instance(ContextType, const realm::List &, bool live = true);
     static ObjectType create_instance(ContextType, SharedRealm, const ObjectSchema &, bool live = true);
-    static ObjectType create_instance(ContextType, SharedRealm, const ObjectSchema &, Query, bool live = true);
 
     template<typename U>
     static ObjectType create_filtered(ContextType, const U &, size_t, const ValueType[]);
@@ -74,8 +73,8 @@ struct ResultsClass : ClassDefinition<T, realm::Results, CollectionClass<T>> {
 };
 
 template<typename T>
-typename T::Object ResultsClass<T>::create_instance(ContextType ctx, const realm::Results &results, bool live) {
-    auto new_results = new realm::Results(results);
+typename T::Object ResultsClass<T>::create_instance(ContextType ctx, realm::Results results, bool live) {
+    auto new_results = new realm::Results(std::move(results));
     new_results->set_live(live);
 
     return create_object<T, ResultsClass<T>>(ctx, new_results);
@@ -83,7 +82,7 @@ typename T::Object ResultsClass<T>::create_instance(ContextType ctx, const realm
 
 template<typename T>
 typename T::Object ResultsClass<T>::create_instance(ContextType ctx, const realm::List &list, bool live) {
-    return create_instance(ctx, list.get_realm(), list.get_object_schema(), list.get_query(), live);
+    return create_instance(ctx, list.sort({}), live);
 }
 
 template<typename T>
@@ -95,21 +94,14 @@ typename T::Object ResultsClass<T>::create_instance(ContextType ctx, SharedRealm
     return create_object<T, ResultsClass<T>>(ctx, results);
 }
 
-template<typename T>
-typename T::Object ResultsClass<T>::create_instance(ContextType ctx, SharedRealm realm, const ObjectSchema &object_schema, Query query, bool live) {
-    auto results = new realm::Results(realm, object_schema, std::move(query));
-    results->set_live(live);
-
-    return create_object<T, ResultsClass<T>>(ctx, results);
-}
-
 template<typename T>
 template<typename U>
 typename T::Object ResultsClass<T>::create_filtered(ContextType ctx, const U &collection, size_t argc, const ValueType arguments[]) {
-    auto query_string = Value::validated_to_string(ctx, arguments[0], "predicate");
-    auto query = collection.get_query();
     auto const &realm = collection.get_realm();
     auto const &object_schema = collection.get_object_schema();
+    auto query = collection.get_table()->where();
+    auto query_string = Value::validated_to_string(ctx, arguments[0], "predicate");
+    auto predicate = parser::parse(query_string);
 
     std::vector<ValueType> args;
     args.reserve(argc - 1);
@@ -118,17 +110,15 @@ typename T::Object ResultsClass<T>::create_filtered(ContextType ctx, const U &co
         args.push_back(arguments[i]);
     }
 
-    parser::Predicate predicate = parser::parse(query_string);
     query_builder::ArgumentConverter<ValueType, ContextType> converter(ctx, realm, args);
     query_builder::apply_predicate(query, predicate, converter, *realm->config().schema, object_schema.name);
 
-    return create_instance(ctx, realm, object_schema, std::move(query));
+    return create_instance(ctx, collection.filter(std::move(query)));
 }
 
 template<typename T>
 template<typename U>
 typename T::Object ResultsClass<T>::create_sorted(ContextType ctx, const U &collection, size_t argc, const ValueType arguments[]) {
-    auto const &realm = collection.get_realm();
     auto const &object_schema = collection.get_object_schema();
     std::vector<std::string> prop_names;
     std::vector<bool> ascending;
@@ -179,8 +169,7 @@ typename T::Object ResultsClass<T>::create_sorted(ContextType ctx, const U &coll
         columns.push_back(prop->table_column);
     }
 
-    auto results = new realm::Results(realm, object_schema, collection.get_query(), {std::move(columns), std::move(ascending)});
-    return create_object<T, ResultsClass<T>>(ctx, results);
+    return create_instance(ctx, collection.sort({std::move(columns), std::move(ascending)}));
 }
 
 template<typename T>

src/object-store/src/list.cpp

@@ -50,6 +50,12 @@ Query List::get_query() const
     return m_link_view->get_target_table().where(m_link_view);
 }
 
+const Table* List::get_table() const
+{
+    verify_attached();
+    return &m_link_view->get_target_table();
+}
+
 size_t List::get_origin_row_index() const
 {
     verify_attached();
@@ -169,13 +175,13 @@ void List::delete_all()
     m_link_view->remove_all_target_rows();
 }
 
-Results List::sort(SortOrder order)
+Results List::sort(SortOrder order) const
 {
     verify_attached();
     return Results(m_realm, *m_object_schema, m_link_view, util::none, std::move(order));
 }
 
-Results List::filter(Query q)
+Results List::filter(Query q) const
 {
     verify_attached();
     return Results(m_realm, *m_object_schema, m_link_view, get_query().and_query(std::move(q)));

src/object-store/src/list.hpp

@@ -51,6 +51,7 @@ public:
     const std::shared_ptr<Realm>& get_realm() const { return m_realm; }
     Query get_query() const;
     const ObjectSchema& get_object_schema() const { return *m_object_schema; }
+    const Table* get_table() const;
     size_t get_origin_row_index() const;
 
     bool is_valid() const;
@@ -72,8 +73,8 @@ public:
 
     void delete_all();
 
-    Results sort(SortOrder order);
-    Results filter(Query q);
+    Results sort(SortOrder order) const;
+    Results filter(Query q) const;
 
     bool operator==(List const& rgt) const noexcept;
 

src/object-store/src/results.cpp

@@ -475,6 +475,12 @@ Query Results::get_query() const
     REALM_UNREACHABLE();
 }
 
+const Table* Results::get_table() const
+{
+    validate_read();
+    return m_table;
+}
+
 TableView Results::get_tableview()
 {
     validate_read();

src/object-store/src/results.hpp

@@ -74,6 +74,9 @@ public:
     // Get the currently applied sort order for this Results
     SortOrder const& get_sort() const noexcept { return m_sort; }
 
+    // Get the table targeted by this Results
+    const Table* get_table() const;
+
     // Get a tableview containing the same rows as this Results
     TableView get_tableview();