cleanup

Author: AlexWaygood

crates/ty_python_semantic/resources/mdtest/protocols.md

@@ -985,7 +985,7 @@ from ty_extensions import is_equivalent_to
 static_assert(is_equivalent_to(UniversalSet, object))
 ```
 
-and that therefore `Any` is a subtype of `UniversalSet` (in general, `Any` can _only_ ever be a
+and that therefore `Any` is a subtype of `UniversalSet` (in general, `Any` can *only* ever be a
 subtype of `object` and types that are equivalent to `object`):
 
 ```py

crates/ty_python_semantic/src/types.rs

@@ -1613,9 +1613,10 @@ impl<'db> Type<'db> {
                 callable.has_relation_to_impl(db, target, relation, visitor)
             }),
 
-            (Type::ProtocolInstance(left), Type::ProtocolInstance(right)) => {
-                left.has_relation_to_impl(db, right, relation, visitor)
-            }
+            (Type::ProtocolInstance(left), Type::ProtocolInstance(right)) => left
+                .interface(db)
+                .extends_interface_of(db, right.interface(db), relation, visitor),
+
             // A protocol instance can never be a subtype of a nominal type, with the *sole* exception of `object`.
             (Type::ProtocolInstance(_), _) => C::unsatisfiable(db),
             (_, Type::ProtocolInstance(protocol)) => {

crates/ty_python_semantic/src/types/instance.rs

@@ -482,6 +482,12 @@ impl<'db> ProtocolInstanceType<'db> {
         }
     }
 
+    /// Return `true` if this protocol is a supertype of `object`.
+    ///
+    /// This indicates that the protocol represents the same set of possible runtime objects
+    /// as `object` (since `object` is the universal set of *all* possible runtime objects!).
+    /// Such a protocol is therefore an equivalent type to `object`, which would in fact be
+    /// normalised to `object`.
     pub(super) fn is_equivalent_to_object(self, db: &'db dyn Db) -> bool {
         #[salsa::tracked(cycle_fn=recover, cycle_initial=initial, heap_size=ruff_memory_usage::heap_size)]
         fn inner<'db>(db: &'db dyn Db, protocol: ProtocolInstanceType<'db>, _: ()) -> bool {
@@ -539,22 +545,6 @@ impl<'db> ProtocolInstanceType<'db> {
         }
     }
 
-    /// Return `true` if this protocol type has the given type relation to the protocol `other`.
-    ///
-    /// TODO: consider the types of the members as well as their existence
-    pub(super) fn has_relation_to_impl<C: Constraints<'db>>(
-        self,
-        db: &'db dyn Db,
-        other: Self,
-        _relation: TypeRelation,
-        visitor: &HasRelationToVisitor<'db, C>,
-    ) -> C {
-        other
-            .inner
-            .interface(db)
-            .is_sub_interface_of(db, self.inner.interface(db), visitor)
-    }
-
     /// Return `true` if this protocol type is equivalent to the protocol `other`.
     ///
     /// TODO: consider the types of the members as well as their existence

crates/ty_python_semantic/src/types/protocol_class.rs

@@ -230,19 +230,21 @@ impl<'db> ProtocolInterface<'db> {
             .unwrap_or_else(|| Type::object(db).member(db, name))
     }
 
-    /// Return `true` if if all members on `self` are also members of `other`.
+    /// Return `true` if `self` extends the interface of `other`, i.e.,
+    /// all members on `other` are also members of `self`.
     ///
     /// TODO: this method should consider the types of the members as well as their names.
-    pub(super) fn is_sub_interface_of<C: Constraints<'db>>(
+    pub(super) fn extends_interface_of<C: Constraints<'db>>(
         self,
         db: &'db dyn Db,
         other: Self,
+        _relation: TypeRelation,
         _visitor: &HasRelationToVisitor<'db, C>,
     ) -> C {
         // TODO: This could just return a bool as written, but this form is what will be needed to
         // combine the constraints when we do assignability checks on each member.
-        self.inner(db).keys().when_all(db, |member_name| {
-            C::from_bool(db, other.inner(db).contains_key(member_name))
+        other.inner(db).keys().when_all(db, |member_name| {
+            C::from_bool(db, self.inner(db).contains_key(member_name))
         })
     }