def check_override(self, override, original, name, supertype, node):
"""Check a method override with given signatures.
Arguments:
override: The signature of the overriding method.
original: The signature of the original supertype method.
name: The name of the subtype. This and the next argument are
only used for generating error messages.
supertype: The name of the supertype.
"""
if (isinstance(override, Overloaded) or
isinstance(original, Overloaded) or
len((override).arg_types) !=
len((original).arg_types) or
(override).min_args !=
(original).min_args):
if not is_subtype(override, original):
self.msg.signature_incompatible_with_supertype(
name, supertype, node)
return
else:
# Give more detailed messages for the common case of both
# signatures having the same number of arguments and no
# intersection types.
coverride = override
coriginal = original
for i in range(len(coverride.arg_types)):
if not is_equivalent(coriginal.arg_types[i],
coverride.arg_types[i]):
self.msg.argument_incompatible_with_supertype(
i + 1, name, supertype, node)
if not is_subtype(coverride.ret_type, coriginal.ret_type):
self.msg.return_type_incompatible_with_supertype(
name, supertype, node)
for iface in t.typ.interfaces:
res.append(map_instance_to_supertype(t, iface))
if t.typ.base is not None:
tt = map_instance_to_supertype(t, t.typ.base)
res.extend(implemented_interfaces(tt))
return res
bool is_similar_callables(Callable t, Callable s):
"""Return True if t and s are equivalent and have identical numbers of
arguments, default arguments and varargs.
"""
return (len(t.arg_types) == len(s.arg_types) and t.min_args == s.min_args
and t.is_var_arg == s.is_var_arg and is_equivalent(t, s))
Callable combine_similar_callables(Callable t, Callable s,
checker.BasicTypes basic):
Typ[] arg_types = []
for i in range(len(t.arg_types)):
arg_types.append(join_types(t.arg_types[i], s.arg_types[i], basic))
# TODO kinds and argument names
return Callable(arg_types,
t.arg_kinds,
t.arg_names,
join_types(t.ret_type, s.ret_type, basic),
t.is_type_obj() and s.is_type_obj(),
None,
t.variables)
def is_similar_callables(t, s):
"""Return True if t and s are equivalent and have identical numbers of
arguments, default arguments and varargs.
"""
return (len(t.arg_types) == len(s.arg_types) and t.min_args == s.min_args
and t.is_var_arg == s.is_var_arg and is_equivalent(t, s))
def check_type_equivalency(self, t1, t2, node, msg=messages.INCOMPATIBLE_TYPES):
"""Generate an error if the types are not equivalent. The
dynamic type is equivalent with all types.
"""
if not is_equivalent(t1, t2):
self.fail(msg, node)
