487941ea66
## Summary One of the follow-ups from augmented assignment inference, now that `Type::Unbound` has been removed. --------- Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2.4 KiB
2.4 KiB
Augmented assignment
Basic
x = 3
x -= 1
reveal_type(x) # revealed: Literal[2]
x = 1.0
x /= 2
reveal_type(x) # revealed: float
Dunder methods
class C:
def __isub__(self, other: int) -> str:
return "Hello, world!"
x = C()
x -= 1
reveal_type(x) # revealed: str
class C:
def __iadd__(self, other: str) -> float:
return 1.0
x = C()
x += "Hello"
reveal_type(x) # revealed: float
Unsupported types
class C:
def __isub__(self, other: str) -> int:
return 42
x = C()
x -= 1
# TODO: should error, once operand type check is implemented
reveal_type(x) # revealed: int
Method union
def bool_instance() -> bool:
return True
flag = bool_instance()
class Foo:
if bool_instance():
def __iadd__(self, other: int) -> str:
return "Hello, world!"
else:
def __iadd__(self, other: int) -> int:
return 42
f = Foo()
f += 12
reveal_type(f) # revealed: str | int
Partially bound __iadd__
def bool_instance() -> bool:
return True
class Foo:
if bool_instance():
def __iadd__(self, other: str) -> int:
return 42
f = Foo()
# TODO: We should emit an `unsupported-operator` error here, possibly with the information
# that `Foo.__iadd__` may be unbound as additional context.
f += "Hello, world!"
reveal_type(f) # revealed: int | @Todo
Partially bound with __add__
def bool_instance() -> bool:
return True
class Foo:
def __add__(self, other: str) -> str:
return "Hello, world!"
if bool_instance():
def __iadd__(self, other: str) -> int:
return 42
f = Foo()
f += "Hello, world!"
reveal_type(f) # revealed: int | str
Partially bound target union
def bool_instance() -> bool:
return True
class Foo:
def __add__(self, other: int) -> str:
return "Hello, world!"
if bool_instance():
def __iadd__(self, other: int) -> int:
return 42
if bool_instance():
f = Foo()
else:
f = 42.0
f += 12
# TODO(charlie): This should be `str | int | float`
reveal_type(f) # revealed: @Todo
Target union
def bool_instance() -> bool:
return True
flag = bool_instance()
class Foo:
def __iadd__(self, other: int) -> str:
return "Hello, world!"
if flag:
f = Foo()
else:
f = 42.0
f += 12
# TODO(charlie): This should be `str | float`.
reveal_type(f) # revealed: @Todo