Add support for type checked term_at<T> and term_at<T>(i)

distr/flecs.h

@@ -29730,6 +29730,8 @@ struct query_builder_i : term_builder_i<Base> {
 
     /* Term notation for more complex query features */
 
+    /** Sets the current term to next one in term list.
+     */
     Base& term() {
         if (this->term_) {
             ecs_check(ecs_term_is_initialized(this->term_), 
@@ -29748,6 +29750,30 @@ struct query_builder_i : term_builder_i<Base> {
         return *this;
     }
 
+    /** Sets the current term to the one with the provided type.
+     * This loops over all terms to find the one with the provided type.
+     * For performance-critical paths, use term_at(int32_t) instead.
+     */
+    template <typename T>
+    Base& term_at() {
+        flecs::id_t term_id = _::type<T>::id(this->world_v());
+        for (int i = 0; i < term_index_; i ++) {
+            ecs_term_t cur_term = desc_->terms[i];
+            ecs_id_t cur_term_id = cur_term.id;
+            ecs_id_t cur_term_pair = ecs_pair(cur_term.first.id, cur_term.second.id);
+
+            if ((term_id == cur_term_id || (cur_term_id != 0 && term_id == ecs_get_typeid(this->world_v(), cur_term_id))) ||
+                (term_id == cur_term_pair || (cur_term_pair != 0 && term_id == ecs_get_typeid(this->world_v(), cur_term_pair)))) {
+                return term_at(i);
+            }
+        }
+
+        ecs_err("term not found");
+        return *this;
+    }
+
+    /** Sets the current term to the one at the provided index.
+     */
     Base& term_at(int32_t term_index) {
         ecs_assert(term_index >= 0, ECS_INVALID_PARAMETER, NULL);
         int32_t prev_index = term_index_;
@@ -29759,6 +29785,24 @@ struct query_builder_i : term_builder_i<Base> {
         return *this;
     }
 
+    /** Sets the current term to the one at the provided index and asserts that the type matches.
+     */
+    template <typename T>
+    Base& term_at(int32_t term_index) {
+        this->term_at(term_index);
+#if !defined(FLECS_NDEBUG) || defined(FLECS_KEEP_ASSERT)
+        flecs::id_t term_id = _::type<T>::id(this->world_v());
+        ecs_term_t cur_term = *this->term_;
+        ecs_id_t cur_term_id = cur_term.id;
+        ecs_id_t cur_term_pair = ecs_pair(cur_term.first.id, cur_term.second.id);
+
+        ecs_assert((term_id == cur_term_id || (cur_term_id != 0 && term_id == ecs_get_typeid(this->world_v(), cur_term_id))) ||
+            (term_id == cur_term_pair || (cur_term_pair != 0 && term_id == ecs_get_typeid(this->world_v(), cur_term_pair))),
+            ECS_INVALID_PARAMETER, "term type mismatch");
+#endif
+        return *this;
+    }
+
     /** Sort the output of a query.
      * This enables sorting of entities across matched tables. As a result of this
      * operation, the order of entities in the matched tables may be changed. 

include/flecs/addons/cpp/mixins/query/builder_i.hpp

@@ -217,6 +217,8 @@ struct query_builder_i : term_builder_i<Base> {
 
     /* Term notation for more complex query features */
 
+    /** Sets the current term to next one in term list.
+     */
     Base& term() {
         if (this->term_) {
             ecs_check(ecs_term_is_initialized(this->term_), 
@@ -235,6 +237,30 @@ struct query_builder_i : term_builder_i<Base> {
         return *this;
     }
 
+    /** Sets the current term to the one with the provided type.
+     * This loops over all terms to find the one with the provided type.
+     * For performance-critical paths, use term_at(int32_t) instead.
+     */
+    template <typename T>
+    Base& term_at() {
+        flecs::id_t term_id = _::type<T>::id(this->world_v());
+        for (int i = 0; i < term_index_; i ++) {
+            ecs_term_t cur_term = desc_->terms[i];
+            ecs_id_t cur_term_id = cur_term.id;
+            ecs_id_t cur_term_pair = ecs_pair(cur_term.first.id, cur_term.second.id);
+
+            if ((term_id == cur_term_id || (cur_term_id != 0 && term_id == ecs_get_typeid(this->world_v(), cur_term_id))) ||
+                (term_id == cur_term_pair || (cur_term_pair != 0 && term_id == ecs_get_typeid(this->world_v(), cur_term_pair)))) {
+                return term_at(i);
+            }
+        }
+
+        ecs_err("term not found");
+        return *this;
+    }
+
+    /** Sets the current term to the one at the provided index.
+     */
     Base& term_at(int32_t term_index) {
         ecs_assert(term_index >= 0, ECS_INVALID_PARAMETER, NULL);
         int32_t prev_index = term_index_;
@@ -246,6 +272,24 @@ struct query_builder_i : term_builder_i<Base> {
         return *this;
     }
 
+    /** Sets the current term to the one at the provided index and asserts that the type matches.
+     */
+    template <typename T>
+    Base& term_at(int32_t term_index) {
+        this->term_at(term_index);
+#if !defined(FLECS_NDEBUG) || defined(FLECS_KEEP_ASSERT)
+        flecs::id_t term_id = _::type<T>::id(this->world_v());
+        ecs_term_t cur_term = *this->term_;
+        ecs_id_t cur_term_id = cur_term.id;
+        ecs_id_t cur_term_pair = ecs_pair(cur_term.first.id, cur_term.second.id);
+
+        ecs_assert((term_id == cur_term_id || (cur_term_id != 0 && term_id == ecs_get_typeid(this->world_v(), cur_term_id))) ||
+            (term_id == cur_term_pair || (cur_term_pair != 0 && term_id == ecs_get_typeid(this->world_v(), cur_term_pair))),
+            ECS_INVALID_PARAMETER, "term type mismatch");
+#endif
+        return *this;
+    }
+
     /** Sort the output of a query.
      * This enables sorting of entities across matched tables. As a result of this
      * operation, the order of entities in the matched tables may be changed. 

test/cpp/project.json

@@ -747,6 +747,8 @@
                 "relation_w_predicate_wildcard",
                 "add_pair_w_rel_type",
                 "template_term",
+                "typed_term_at",
+                "typed_term_at_indexed",
                 "explicit_subject_w_id",
                 "explicit_subject_w_type",
                 "explicit_object_w_id",

test/cpp/src/QueryBuilder.cpp

@@ -1592,6 +1592,54 @@ void QueryBuilder_template_term(void) {
     test_int(count, 1);
 }
 
+void QueryBuilder_typed_term_at(void) {
+    flecs::world ecs;
+
+    struct Rel { int foo; };
+
+    int32_t count = 0;
+
+    auto s = ecs.system<Rel, const Velocity>()
+        .term_at<Velocity>().singleton()
+        .term_at<Rel>().second(flecs::Wildcard)
+        .run([&](flecs::iter it){
+            while (it.next()) {
+                count += it.count();
+            }
+        });
+
+    ecs.entity().add<Rel, Tag>();
+    ecs.set<Velocity>({});
+
+    s.run();
+
+    test_int(count, 1);
+}
+
+void QueryBuilder_typed_term_at_indexed(void) {
+    flecs::world ecs;
+
+    struct Rel { int foo; };
+
+    int32_t count = 0;
+
+    auto s = ecs.system<Rel, const Velocity>()
+        .term_at<Velocity>(1).singleton()
+        .term_at<Rel>(0).second(flecs::Wildcard)
+        .run([&](flecs::iter it){
+            while (it.next()) {
+                count += it.count();
+            }
+        });
+
+    ecs.entity().add<Rel, Tag>();
+    ecs.set<Velocity>({});
+
+    s.run();
+
+    test_int(count, 1);
+}
+
 void QueryBuilder_explicit_subject_w_id(void) {
     flecs::world ecs;
 

test/cpp/src/main.cpp

@@ -718,6 +718,8 @@ void QueryBuilder_relation_w_object_wildcard(void);
 void QueryBuilder_relation_w_predicate_wildcard(void);
 void QueryBuilder_add_pair_w_rel_type(void);
 void QueryBuilder_template_term(void);
+void QueryBuilder_typed_term_at(void);
+void QueryBuilder_typed_term_at_indexed(void);
 void QueryBuilder_explicit_subject_w_id(void);
 void QueryBuilder_explicit_subject_w_type(void);
 void QueryBuilder_explicit_object_w_id(void);
@@ -4160,6 +4162,14 @@ bake_test_case QueryBuilder_testcases[] = {
         "template_term",
         QueryBuilder_template_term
     },
+    {
+        "typed_term_at",
+        QueryBuilder_typed_term_at
+    },
+    {
+        "typed_term_at_indexed",
+        QueryBuilder_typed_term_at_indexed
+    },
     {
         "explicit_subject_w_id",
         QueryBuilder_explicit_subject_w_id
@@ -6805,7 +6815,7 @@ static bake_test_suite suites[] = {
         "QueryBuilder",
         QueryBuilder_setup,
         NULL,
-        166,
+        168,
         QueryBuilder_testcases,
         1,
         QueryBuilder_params