Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

[red-knot] all types are assignable to object #15332

Merged
merged 5 commits into from
Jan 7, 2025
+72 −8
Merged

[red-knot] all types are assignable to object #15332

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
32fb307
[red-knot] all types are assignable to object
carljm Jan 7, 2025
7bf007a
fix benchmark
carljm Jan 7, 2025
6b03eab
Update crates/red_knot_python_semantic/src/types/property_tests.rs
carljm Jan 7, 2025
ff31f51
all negation types are still subtypes of object
carljm Jan 7, 2025
deca8c7
add comments to is_assignable_to cases
carljm Jan 7, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
63 changes: 57 additions & 6 deletions crates/red_knot_python_semantic/src/types.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -769,6 +769,14 @@ impl<'db> Type<'db> {
.iter()
.any(|&elem_ty| self.is_subtype_of(db, elem_ty)),

// `object` is the only type that can be known to be a supertype of any intersection,
// even an intersection with no positive elements
(Type::Intersection(_), Type::Instance(InstanceType { class }))
if class.is_known(db, KnownClass::Object) =>
{
true
}
carljm marked this conversation as resolved.
Show resolved Hide resolved

carljm marked this conversation as resolved.
Show resolved Hide resolved
(Type::Intersection(self_intersection), Type::Intersection(target_intersection)) => {
// Check that all target positive values are covered in self positive values
target_intersection
Expand Down Expand Up @@ -954,16 +962,32 @@ impl<'db> Type<'db> {
return true;
}
match (self, target) {
// The dynamic type is assignable-to and assignable-from any type.
(Type::Unknown | Type::Any | Type::Todo(_), _) => true,
(_, Type::Unknown | Type::Any | Type::Todo(_)) => true,

// All types are assignable to `object`.
// TODO this special case might be removable once the below cases are comprehensive
(_, Type::Instance(InstanceType { class }))
if class.is_known(db, KnownClass::Object) =>
{
true
}

// A union is assignable to a type T iff every element of the union is assignable to T.
(Type::Union(union), ty) => union
.elements(db)
.iter()
.all(|&elem_ty| elem_ty.is_assignable_to(db, ty)),

// A type T is assignable to a union iff T is assignable to any element of the union.
(ty, Type::Union(union)) => union
.elements(db)
.iter()
.any(|&elem_ty| ty.is_assignable_to(db, elem_ty)),

// A tuple type S is assignable to a tuple type T if their lengths are the same, and
// each element of S is assignable to the corresponding element of T.
(Type::Tuple(self_tuple), Type::Tuple(target_tuple)) => {
let self_elements = self_tuple.elements(db);
let target_elements = target_tuple.elements(db);
Expand All @@ -974,28 +998,53 @@ impl<'db> Type<'db> {
},
)
}

// `type[Any]` is assignable to any `type[...]` type, because `type[Any]` can
// materialize to any `type[...]` type.
(Type::SubclassOf(subclass_of_ty), Type::SubclassOf(_))
if subclass_of_ty.is_dynamic() =>
{
true
}

// All `type[...]` types are assignable to `type[Any]`, because `type[Any]` can
// materialize to any `type[...]` type.
//
// Every class literal type is also assignable to `type[Any]`, because the class
// literal type for a class `C` is a subtype of `type[C]`, and `type[C]` is assignable
// to `type[Any]`.
(Type::ClassLiteral(_) | Type::SubclassOf(_), Type::SubclassOf(target_subclass_of))
if target_subclass_of.is_dynamic() =>
{
true
}

// `type[Any]` is assignable to any type that `type[object]` is assignable to, because
// `type[Any]` can materialize to `type[object]`.
//
// `type[Any]` is also assignable to any subtype of `type[object]`, because all
// subtypes of `type[object]` are `type[...]` types (or `Never`), and `type[Any]` can
// materialize to any `type[...]` type (or to `type[Never]`, which is equivalent to
// `Never`.)
(Type::SubclassOf(subclass_of_ty), Type::Instance(_))
if subclass_of_ty.is_dynamic()
&& target.is_assignable_to(db, KnownClass::Type.to_instance(db)) =>
&& (KnownClass::Type
.to_instance(db)
.is_assignable_to(db, target)
|| target.is_subtype_of(db, KnownClass::Type.to_instance(db))) =>
{
true
}

// Any type that is assignable to `type[object]` is also assignable to `type[Any]`,
// because `type[Any]` can materialize to `type[object]`.
(Type::Instance(_), Type::SubclassOf(subclass_of_ty))
if subclass_of_ty.is_dynamic()
&& self.is_assignable_to(db, KnownClass::Type.to_instance(db)) =>
{
true
}
(Type::ClassLiteral(_) | Type::SubclassOf(_), Type::SubclassOf(target_subclass_of))
if target_subclass_of.is_dynamic() =>
{
true
}

// TODO other types containing gradual forms (e.g. generics containing Any/Unknown)
_ => self.is_subtype_of(db, target),
}
Expand Down Expand Up @@ -3893,6 +3942,7 @@ pub(crate) mod tests {
#[test_case(Ty::SubclassOfUnknown, Ty::SubclassOfBuiltinClass("str"))]
#[test_case(Ty::SubclassOfAny, Ty::AbcInstance("ABCMeta"))]
#[test_case(Ty::SubclassOfUnknown, Ty::AbcInstance("ABCMeta"))]
#[test_case(Ty::SubclassOfAny, Ty::BuiltinInstance("object"))]
fn is_assignable_to(from: Ty, to: Ty) {
let db = setup_db();
assert!(from.into_type(&db).is_assignable_to(&db, to.into_type(&db)));
Expand Down Expand Up @@ -3976,6 +4026,7 @@ pub(crate) mod tests {
#[test_case(Ty::Never, Ty::AlwaysTruthy)]
#[test_case(Ty::Never, Ty::AlwaysFalsy)]
#[test_case(Ty::BuiltinClassLiteral("bool"), Ty::SubclassOfBuiltinClass("int"))]
#[test_case(Ty::Intersection{pos: vec![], neg: vec![Ty::LiteralString]}, Ty::BuiltinInstance("object"))]
fn is_subtype_of(from: Ty, to: Ty) {
let db = setup_db();
assert!(from.into_type(&db).is_subtype_of(&db, to.into_type(&db)));
Expand Down
14 changes: 14 additions & 0 deletions crates/red_knot_python_semantic/src/types/property_tests.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -220,6 +220,8 @@ macro_rules! type_property_test {
}

mod stable {
use super::KnownClass;

// `T` is equivalent to itself.
type_property_test!(
equivalent_to_is_reflexive, db,
Expand Down Expand Up @@ -285,6 +287,18 @@ mod stable {
non_fully_static_types_do_not_participate_in_subtyping, db,
forall types s, t. !s.is_fully_static(db) => !s.is_subtype_of(db, t) && !t.is_subtype_of(db, s)
);

// All types should be assignable to `object`
type_property_test!(
all_types_assignable_to_object, db,
forall types t. t.is_assignable_to(db, KnownClass::Object.to_instance(db))
);

// And for fully static types, they should also be subtypes of `object`
type_property_test!(
all_fully_static_types_subtype_of_object, db,
forall types t. t.is_fully_static(db) => t.is_subtype_of(db, KnownClass::Object.to_instance(db))
);
carljm marked this conversation as resolved.
Show resolved Hide resolved
}

/// This module contains property tests that currently lead to many false positives.
Expand Down
3 changes: 1 addition & 2 deletions crates/ruff_benchmark/benches/red_knot.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -33,8 +33,6 @@ static EXPECTED_DIAGNOSTICS: &[&str] = &[
"warning[lint:possibly-unresolved-reference] /src/tomllib/_parser.py:104:14 Name `char` used when possibly not defined",
"warning[lint:possibly-unresolved-reference] /src/tomllib/_parser.py:115:14 Name `char` used when possibly not defined",
"warning[lint:possibly-unresolved-reference] /src/tomllib/_parser.py:126:12 Name `char` used when possibly not defined",
// We don't handle intersections in `is_assignable_to` yet
"error[lint:invalid-argument-type] /src/tomllib/_parser.py:211:31 Object of type `Unknown & object | @Todo` cannot be assigned to parameter 1 (`obj`) of function `isinstance`; expected type `object`",
"warning[lint:possibly-unresolved-reference] /src/tomllib/_parser.py:348:20 Name `nest` used when possibly not defined",
"warning[lint:possibly-unresolved-reference] /src/tomllib/_parser.py:353:5 Name `nest` used when possibly not defined",
"warning[lint:possibly-unresolved-reference] /src/tomllib/_parser.py:453:24 Name `nest` used when possibly not defined",
Expand All @@ -44,6 +42,7 @@ static EXPECTED_DIAGNOSTICS: &[&str] = &[
"warning[lint:possibly-unresolved-reference] /src/tomllib/_parser.py:573:12 Name `char` used when possibly not defined",
"warning[lint:possibly-unresolved-reference] /src/tomllib/_parser.py:579:12 Name `char` used when possibly not defined",
"warning[lint:possibly-unresolved-reference] /src/tomllib/_parser.py:580:63 Name `char` used when possibly not defined",
// We don't handle intersections in `is_assignable_to` yet
"error[lint:invalid-argument-type] /src/tomllib/_parser.py:626:46 Object of type `@Todo & ~AlwaysFalsy` cannot be assigned to parameter 1 (`match`) of function `match_to_datetime`; expected type `Match`",
"warning[lint:possibly-unresolved-reference] /src/tomllib/_parser.py:629:38 Name `datetime_obj` used when possibly not defined",
"error[lint:invalid-argument-type] /src/tomllib/_parser.py:632:58 Object of type `@Todo & ~AlwaysFalsy` cannot be assigned to parameter 1 (`match`) of function `match_to_localtime`; expected type `Match`",
Expand Down
Loading