def is_overlapping_erased_types(left: Type,
right: Type,
*,
ignore_promotions: bool = False) -> bool:
"""The same as 'is_overlapping_erased_types', except the types are erased first."""
return is_overlapping_types(erase_type(left),
erase_type(right),
ignore_promotions=ignore_promotions,
prohibit_none_typevar_overlap=True)
def check_instance_definition(
passed_types: TupleType,
instance_signature: CallableType,
fullname: str,
ctx: MethodContext,
) -> _RuntimeValidationContext:
"""
Checks runtime type.
We call "runtime types" things that we use at runtime to dispatch our calls.
For example:
1. We check that type passed in ``some.instance(...)`` matches
one defined in a type annotation
2. We check that types don't have any concrete types
3. We check that types don't have any unbound type variables
4. We check that ``is_protocol`` is passed correctly
"""
runtime_type = inference.infer_runtime_type_from_context(
fallback=passed_types.items[0],
fullname=fullname,
ctx=ctx,
)
if len(passed_types.items) == 2:
is_protocol, protocol_arg_check = _check_protocol_arg(passed_types, ctx)
else:
is_protocol = False
protocol_arg_check = True
instance_type = instance_signature.arg_types[0]
instance_check = is_same_type(
erase_type(instance_type),
erase_type(runtime_type),
)
if not instance_check:
ctx.api.fail(
_INSTANCE_RUNTIME_MISMATCH_MSG.format(instance_type, runtime_type),
ctx.context,
)
return _RuntimeValidationContext(runtime_type, is_protocol, all([
_check_runtime_protocol(runtime_type, ctx, is_protocol=is_protocol),
_check_concrete_generics(runtime_type, instance_type, ctx),
_check_tuple_size(instance_type, ctx),
protocol_arg_check,
instance_check,
]))
def restrict_subtype_away(t: Type, s: Type) -> Type:
"""Return t minus s.
If we can't determine a precise result, return a supertype of the
ideal result (just t is a valid result).
This is used for type inference of runtime type checks such as
isinstance.
Currently this just removes elements of a union type.
"""
if isinstance(t, UnionType):
# Since runtime type checks will ignore type arguments, erase the types.
erased_s = erase_type(s)
new_items = [item for item in t.relevant_items()
if (not is_proper_subtype(erase_type(item), erased_s)
or isinstance(item, AnyType))]
return UnionType.make_union(new_items)
else:
return t
def format(self, typ: Type, verbosity: int = 0) -> str:
"""Convert a type to a relatively short string that is suitable for error messages.
Mostly behave like format_simple below, but never return an empty string.
"""
s = self.format_simple(typ, verbosity)
if s != '':
# If format_simple returns a non-trivial result, use that.
return s
elif isinstance(typ, FunctionLike):
func = typ
if func.is_type_obj():
# The type of a type object type can be derived from the
# return type (this always works).
return self.format(
TypeType.make_normalized(
erase_type(func.items()[0].ret_type)), verbosity)
elif isinstance(func, CallableType):
return_type = strip_quotes(self.format(func.ret_type))
if func.is_ellipsis_args:
return 'Callable[..., {}]'.format(return_type)
arg_strings = []
for arg_name, arg_type, arg_kind in zip(
func.arg_names, func.arg_types, func.arg_kinds):
if (arg_kind == ARG_POS and arg_name is None or
verbosity == 0 and arg_kind in (ARG_POS, ARG_OPT)):
arg_strings.append(
strip_quotes(
self.format(arg_type,
verbosity=max(verbosity - 1, 0))))
else:
constructor = ARG_CONSTRUCTOR_NAMES[arg_kind]
if arg_kind in (ARG_STAR,
ARG_STAR2) or arg_name is None:
arg_strings.append("{}({})".format(
constructor,
strip_quotes(self.format(arg_type))))
else:
arg_strings.append("{}({}, {})".format(
constructor,
strip_quotes(self.format(arg_type)),
repr(arg_name)))
return 'Callable[[{}], {}]'.format(", ".join(arg_strings),
return_type)
else:
# Use a simple representation for function types; proper
# function types may result in long and difficult-to-read
# error messages.
return 'overloaded function'
else:
# Default case; we simply have to return something meaningful here.
return 'object'
def restrict_subtype_away(t: Type, s: Type) -> Type:
"""Return t minus s.
If we can't determine a precise result, return a supertype of the
ideal result (just t is a valid result).
This is used for type inference of runtime type checks such as
isinstance.
Currently this just removes elements of a union type.
"""
if isinstance(t, UnionType):
# Since runtime type checks will ignore type arguments, erase the types.
erased_s = erase_type(s)
# TODO: Implement more robust support for runtime isinstance() checks,
# see issue #3827
new_items = [item for item in t.relevant_items()
if (not (is_proper_subtype(erase_type(item), erased_s) or
is_proper_subtype(item, erased_s))
or isinstance(item, AnyType))]
return UnionType.make_union(new_items)
else:
return t
def assert_erase(self, orig, result):
assert_equal(str(erase_type(orig)), str(result))
def assert_erase(self, orig: Type, result: Type) -> None:
assert_equal(str(erase_type(orig)), str(result))
def assert_erase(self, orig: Type, result: Type) -> None:
assert_equal(str(erase_type(orig)), str(result))
def is_overlapping_erased_types(left: Type, right: Type, *,
ignore_promotions: bool = False) -> bool:
"""The same as 'is_overlapping_erased_types', except the types are erased first."""
return is_overlapping_types(erase_type(left), erase_type(right),
ignore_promotions=ignore_promotions,
prohibit_none_typevar_overlap=True)
def assert_erase(self, orig, result):
assert_equal(str(erase_type(orig)), str(result))
def assert_erase(self, orig, result):
assert_equal(str(erase_type(orig, self.fx.basic)), str(result))
def assert_erase(self, orig, result):
assert_equal(str(erase_type(orig, self.fx.basic)), str(result))