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Merged
merged 18 commits into from
Nov 19, 2025
Merged

[ty] Create a specialization from a constraint set #21414

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aa5ca1f
retain_one
dcreager Nov 12, 2025
922408f
create spec from constraint set
dcreager Nov 12, 2025
a63cc39
add GenericContext mdtest class
dcreager Nov 12, 2025
0e56470
add Specialization mdtest class
dcreager Nov 12, 2025
a6a10d9
add GenericContext.specialize_constrained mdtest method
dcreager Nov 12, 2025
c2cbbc0
babby's first test
dcreager Nov 12, 2025
e32bdfc
many more tests
dcreager Nov 13, 2025
27d8fd2
lint
dcreager Nov 17, 2025
7f31e4e
turn off some auto-formatting
dcreager Nov 17, 2025
4214f35
mutually bound
dcreager Nov 17, 2025
036c892
don't format!
dcreager Nov 17, 2025
1c9744d
normalize for consistent output
dcreager Nov 17, 2025
4327616
does this fix the macos thing?
dcreager Nov 19, 2025
81df564
Merge remote-tracking branch 'origin/main' into HEAD
dcreager Nov 19, 2025
580d5a3
handle constrained typevars correctly
dcreager Nov 18, 2025
cdf2f79
consider bounds when removing/retaining
dcreager Nov 19, 2025
05cfd3c
reword comment
dcreager Nov 19, 2025
7ec2fbe
add todos for gradual constraints
dcreager Nov 19, 2025
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12 changes: 8 additions & 4 deletions crates/ty_python_semantic/resources/mdtest/annotations/self.md
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Original file line number Diff line number Diff line change
Expand Up @@ -503,9 +503,11 @@ class C[T]():
def f(self: Self):
def b(x: Self):
reveal_type(x) # revealed: Self@f
reveal_type(generic_context(b)) # revealed: None
# revealed: None
reveal_type(generic_context(b))

reveal_type(generic_context(C.f)) # revealed: tuple[Self@f]
# revealed: ty_extensions.GenericContext[Self@f]
reveal_type(generic_context(C.f))
```

Even if the `Self` annotation appears first in the nested function, it is the method that binds
Expand All @@ -519,9 +521,11 @@ class C:
def f(self: "C"):
def b(x: Self):
reveal_type(x) # revealed: Self@f
reveal_type(generic_context(b)) # revealed: None
# revealed: None
reveal_type(generic_context(b))

reveal_type(generic_context(C.f)) # revealed: None
# revealed: None
reveal_type(generic_context(C.f))
```

## Non-positional first parameters
Expand Down
47 changes: 28 additions & 19 deletions crates/ty_python_semantic/resources/mdtest/generics/legacy/classes.md
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Original file line number Diff line number Diff line change
Expand Up @@ -21,14 +21,14 @@ class TypeVarAndParamSpec(Generic[P, T]): ...
class SingleTypeVarTuple(Generic[Unpack[Ts]]): ...
class TypeVarAndTypeVarTuple(Generic[T, Unpack[Ts]]): ...

# revealed: tuple[T@SingleTypevar]
# revealed: ty_extensions.GenericContext[T@SingleTypevar]
reveal_type(generic_context(SingleTypevar))
# revealed: tuple[T@MultipleTypevars, S@MultipleTypevars]
# revealed: ty_extensions.GenericContext[T@MultipleTypevars, S@MultipleTypevars]
reveal_type(generic_context(MultipleTypevars))

# revealed: tuple[P@SingleParamSpec]
# revealed: ty_extensions.GenericContext[P@SingleParamSpec]
reveal_type(generic_context(SingleParamSpec))
# revealed: tuple[P@TypeVarAndParamSpec, T@TypeVarAndParamSpec]
# revealed: ty_extensions.GenericContext[P@TypeVarAndParamSpec, T@TypeVarAndParamSpec]
reveal_type(generic_context(TypeVarAndParamSpec))

# TODO: support `TypeVarTuple` properly (these should not reveal `None`)
Expand Down Expand Up @@ -66,9 +66,9 @@ class InheritedGeneric(MultipleTypevars[T, S]): ...
class InheritedGenericPartiallySpecialized(MultipleTypevars[T, int]): ...
class InheritedGenericFullySpecialized(MultipleTypevars[str, int]): ...

# revealed: tuple[T@InheritedGeneric, S@InheritedGeneric]
# revealed: ty_extensions.GenericContext[T@InheritedGeneric, S@InheritedGeneric]
reveal_type(generic_context(InheritedGeneric))
# revealed: tuple[T@InheritedGenericPartiallySpecialized]
# revealed: ty_extensions.GenericContext[T@InheritedGenericPartiallySpecialized]
reveal_type(generic_context(InheritedGenericPartiallySpecialized))
# revealed: None
reveal_type(generic_context(InheritedGenericFullySpecialized))
Expand All @@ -90,7 +90,7 @@ class OuterClass(Generic[T]):
# revealed: None
reveal_type(generic_context(InnerClassInMethod))

# revealed: tuple[T@OuterClass]
# revealed: ty_extensions.GenericContext[T@OuterClass]
reveal_type(generic_context(OuterClass))
```

Expand Down Expand Up @@ -118,11 +118,11 @@ class ExplicitInheritedGenericPartiallySpecializedExtraTypevar(MultipleTypevars[
# error: [invalid-generic-class] "`Generic` base class must include all type variables used in other base classes"
class ExplicitInheritedGenericPartiallySpecializedMissingTypevar(MultipleTypevars[T, int], Generic[S]): ...

# revealed: tuple[T@ExplicitInheritedGeneric, S@ExplicitInheritedGeneric]
# revealed: ty_extensions.GenericContext[T@ExplicitInheritedGeneric, S@ExplicitInheritedGeneric]
reveal_type(generic_context(ExplicitInheritedGeneric))
# revealed: tuple[T@ExplicitInheritedGenericPartiallySpecialized]
# revealed: ty_extensions.GenericContext[T@ExplicitInheritedGenericPartiallySpecialized]
reveal_type(generic_context(ExplicitInheritedGenericPartiallySpecialized))
# revealed: tuple[T@ExplicitInheritedGenericPartiallySpecializedExtraTypevar, S@ExplicitInheritedGenericPartiallySpecializedExtraTypevar]
# revealed: ty_extensions.GenericContext[T@ExplicitInheritedGenericPartiallySpecializedExtraTypevar, S@ExplicitInheritedGenericPartiallySpecializedExtraTypevar]
reveal_type(generic_context(ExplicitInheritedGenericPartiallySpecializedExtraTypevar))
```

Expand Down Expand Up @@ -594,18 +594,27 @@ class C(Generic[T]):
def generic_method(self, t: T, u: U) -> U:
return u

reveal_type(generic_context(C)) # revealed: tuple[T@C]
reveal_type(generic_context(C.method)) # revealed: tuple[Self@method]
reveal_type(generic_context(C.generic_method)) # revealed: tuple[Self@generic_method, U@generic_method]
reveal_type(generic_context(C[int])) # revealed: None
reveal_type(generic_context(C[int].method)) # revealed: tuple[Self@method]
reveal_type(generic_context(C[int].generic_method)) # revealed: tuple[Self@generic_method, U@generic_method]
# revealed: ty_extensions.GenericContext[T@C]
reveal_type(generic_context(C))
# revealed: ty_extensions.GenericContext[Self@method]
reveal_type(generic_context(C.method))
# revealed: ty_extensions.GenericContext[Self@generic_method, U@generic_method]
reveal_type(generic_context(C.generic_method))
# revealed: None
reveal_type(generic_context(C[int]))
# revealed: ty_extensions.GenericContext[Self@method]
reveal_type(generic_context(C[int].method))
# revealed: ty_extensions.GenericContext[Self@generic_method, U@generic_method]
reveal_type(generic_context(C[int].generic_method))

c: C[int] = C[int]()
reveal_type(c.generic_method(1, "string")) # revealed: Literal["string"]
reveal_type(generic_context(c)) # revealed: None
reveal_type(generic_context(c.method)) # revealed: tuple[Self@method]
reveal_type(generic_context(c.generic_method)) # revealed: tuple[Self@generic_method, U@generic_method]
# revealed: None
reveal_type(generic_context(c))
# revealed: ty_extensions.GenericContext[Self@method]
reveal_type(generic_context(c.method))
# revealed: ty_extensions.GenericContext[Self@generic_method, U@generic_method]
reveal_type(generic_context(c.generic_method))
```

## Specializations propagate
Expand Down
16 changes: 10 additions & 6 deletions crates/ty_python_semantic/resources/mdtest/generics/pep695/aliases.md
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -20,17 +20,21 @@ type TypeVarAndParamSpec[T, **P] = ...
type SingleTypeVarTuple[*Ts] = ...
type TypeVarAndTypeVarTuple[T, *Ts] = ...

# revealed: tuple[T@SingleTypevar]
# revealed: ty_extensions.GenericContext[T@SingleTypevar]
reveal_type(generic_context(SingleTypevar))
# revealed: tuple[T@MultipleTypevars, S@MultipleTypevars]
# revealed: ty_extensions.GenericContext[T@MultipleTypevars, S@MultipleTypevars]
reveal_type(generic_context(MultipleTypevars))

# TODO: support `ParamSpec`/`TypeVarTuple` properly
# (these should include the `ParamSpec`s and `TypeVarTuple`s in their generic contexts)
reveal_type(generic_context(SingleParamSpec)) # revealed: tuple[()]
reveal_type(generic_context(TypeVarAndParamSpec)) # revealed: tuple[T@TypeVarAndParamSpec]
reveal_type(generic_context(SingleTypeVarTuple)) # revealed: tuple[()]
reveal_type(generic_context(TypeVarAndTypeVarTuple)) # revealed: tuple[T@TypeVarAndTypeVarTuple]
# revealed: ty_extensions.GenericContext[]
reveal_type(generic_context(SingleParamSpec))
# revealed: ty_extensions.GenericContext[T@TypeVarAndParamSpec]
reveal_type(generic_context(TypeVarAndParamSpec))
# revealed: ty_extensions.GenericContext[]
reveal_type(generic_context(SingleTypeVarTuple))
# revealed: ty_extensions.GenericContext[T@TypeVarAndTypeVarTuple]
reveal_type(generic_context(TypeVarAndTypeVarTuple))
```

You cannot use the same typevar more than once.
Expand Down
50 changes: 32 additions & 18 deletions crates/ty_python_semantic/resources/mdtest/generics/pep695/classes.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -20,17 +20,21 @@ class TypeVarAndParamSpec[T, **P]: ...
class SingleTypeVarTuple[*Ts]: ...
class TypeVarAndTypeVarTuple[T, *Ts]: ...

# revealed: tuple[T@SingleTypevar]
# revealed: ty_extensions.GenericContext[T@SingleTypevar]
reveal_type(generic_context(SingleTypevar))
# revealed: tuple[T@MultipleTypevars, S@MultipleTypevars]
# revealed: ty_extensions.GenericContext[T@MultipleTypevars, S@MultipleTypevars]
reveal_type(generic_context(MultipleTypevars))

# TODO: support `ParamSpec`/`TypeVarTuple` properly
# (these should include the `ParamSpec`s and `TypeVarTuple`s in their generic contexts)
reveal_type(generic_context(SingleParamSpec)) # revealed: tuple[()]
reveal_type(generic_context(TypeVarAndParamSpec)) # revealed: tuple[T@TypeVarAndParamSpec]
reveal_type(generic_context(SingleTypeVarTuple)) # revealed: tuple[()]
reveal_type(generic_context(TypeVarAndTypeVarTuple)) # revealed: tuple[T@TypeVarAndTypeVarTuple]
# revealed: ty_extensions.GenericContext[]
reveal_type(generic_context(SingleParamSpec))
# revealed: ty_extensions.GenericContext[T@TypeVarAndParamSpec]
reveal_type(generic_context(TypeVarAndParamSpec))
# revealed: ty_extensions.GenericContext[]
reveal_type(generic_context(SingleTypeVarTuple))
# revealed: ty_extensions.GenericContext[T@TypeVarAndTypeVarTuple]
reveal_type(generic_context(TypeVarAndTypeVarTuple))
```

You cannot use the same typevar more than once.
Expand All @@ -49,9 +53,9 @@ class InheritedGeneric[U, V](MultipleTypevars[U, V]): ...
class InheritedGenericPartiallySpecialized[U](MultipleTypevars[U, int]): ...
class InheritedGenericFullySpecialized(MultipleTypevars[str, int]): ...

# revealed: tuple[U@InheritedGeneric, V@InheritedGeneric]
# revealed: ty_extensions.GenericContext[U@InheritedGeneric, V@InheritedGeneric]
reveal_type(generic_context(InheritedGeneric))
# revealed: tuple[U@InheritedGenericPartiallySpecialized]
# revealed: ty_extensions.GenericContext[U@InheritedGenericPartiallySpecialized]
reveal_type(generic_context(InheritedGenericPartiallySpecialized))
# revealed: None
reveal_type(generic_context(InheritedGenericFullySpecialized))
Expand All @@ -64,7 +68,8 @@ the inheriting class generic.
```py
class InheritedGenericDefaultSpecialization(MultipleTypevars): ...

reveal_type(generic_context(InheritedGenericDefaultSpecialization)) # revealed: None
# revealed: None
reveal_type(generic_context(InheritedGenericDefaultSpecialization))
```

You cannot use PEP-695 syntax and the legacy syntax in the same class definition.
Expand Down Expand Up @@ -512,18 +517,27 @@ class C[T]:
# TODO: error
def cannot_shadow_class_typevar[T](self, t: T): ...

reveal_type(generic_context(C)) # revealed: tuple[T@C]
reveal_type(generic_context(C.method)) # revealed: tuple[Self@method]
reveal_type(generic_context(C.generic_method)) # revealed: tuple[Self@generic_method, U@generic_method]
reveal_type(generic_context(C[int])) # revealed: None
reveal_type(generic_context(C[int].method)) # revealed: tuple[Self@method]
reveal_type(generic_context(C[int].generic_method)) # revealed: tuple[Self@generic_method, U@generic_method]
# revealed: ty_extensions.GenericContext[T@C]
reveal_type(generic_context(C))
# revealed: ty_extensions.GenericContext[Self@method]
reveal_type(generic_context(C.method))
# revealed: ty_extensions.GenericContext[Self@generic_method, U@generic_method]
reveal_type(generic_context(C.generic_method))
# revealed: None
reveal_type(generic_context(C[int]))
# revealed: ty_extensions.GenericContext[Self@method]
reveal_type(generic_context(C[int].method))
# revealed: ty_extensions.GenericContext[Self@generic_method, U@generic_method]
reveal_type(generic_context(C[int].generic_method))

c: C[int] = C[int]()
reveal_type(c.generic_method(1, "string")) # revealed: Literal["string"]
reveal_type(generic_context(c)) # revealed: None
reveal_type(generic_context(c.method)) # revealed: tuple[Self@method]
reveal_type(generic_context(c.generic_method)) # revealed: tuple[Self@generic_method, U@generic_method]
# revealed: None
reveal_type(generic_context(c))
# revealed: ty_extensions.GenericContext[Self@method]
reveal_type(generic_context(c.method))
# revealed: ty_extensions.GenericContext[Self@generic_method, U@generic_method]
reveal_type(generic_context(c.generic_method))
```

## Specializations propagate
Expand Down
6 changes: 4 additions & 2 deletions crates/ty_python_semantic/resources/mdtest/generics/scoping.md
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -154,8 +154,10 @@ from ty_extensions import generic_context

legacy.m("string", None) # error: [invalid-argument-type]
reveal_type(legacy.m) # revealed: bound method Legacy[int].m[S](x: int, y: S@m) -> S@m
reveal_type(generic_context(Legacy)) # revealed: tuple[T@Legacy]
reveal_type(generic_context(legacy.m)) # revealed: tuple[Self@m, S@m]
# revealed: ty_extensions.GenericContext[T@Legacy]
reveal_type(generic_context(Legacy))
# revealed: ty_extensions.GenericContext[Self@m, S@m]
reveal_type(generic_context(legacy.m))
```

With PEP 695 syntax, it is clearer that the method uses a separate typevar:
Expand Down
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