def test_mro_merge(self):
self.assertEqual([], mro.MROMerge([[], []]))
self.assertEqual([1], mro.MROMerge([[], [1]]))
self.assertEqual([1], mro.MROMerge([[1], []]))
self.assertEqual([1, 2], mro.MROMerge([[1], [2]]))
self.assertEqual([1, 2], mro.MROMerge([[1, 2], [2]]))
self.assertEqual([1, 2, 3, 4], mro.MROMerge([[1, 2, 3], [2, 4]]))
self.assertEqual([1, 2, 3], mro.MROMerge([[1, 2], [1, 2, 3]]))
self.assertEqual([1, 2], mro.MROMerge([[1, 1], [2, 2]]))
self.assertEqual([1, 2, 3, 4, 5, 6],
mro.MROMerge([[1, 3, 5], [2, 3, 4], [4, 5, 6]]))
self.assertEqual([1, 2, 3], mro.MROMerge([[1, 2, 1], [2, 3, 2]]))
def compute_mro(self):
"""Compute the class precedence list (mro) according to C3."""
bases = abstract_utils.get_mro_bases(self.bases(), self.vm)
bases = [[self]] + [list(base.mro) for base in bases] + [list(bases)]
# If base classes are `ParameterizedClass`, we will use their `base_cls` to
# calculate the MRO. Bacause of type parameter renaming, we can not compare
# the `ParameterizedClass`s which contain the same `base_cls`. See example:
# class A(Iterator[T]): ...
# class B(Iterator[U], A[V]): ...
# The inheritance: [B], [Iterator, ...], [A, Iterator, ...], [Iterator, A]
# So this has MRO order issue, but because the template names of
# `ParameterizedClass` of `Iterator` are different, they will be treated as
# different base classes and it will infer the MRO order is correct.
# TODO(b/159044968): fix this by solving the template rename problem
base2cls = {}
newbases = []
for row in bases:
baselist = []
for base in row:
if base.isinstance_ParameterizedClass():
base2cls[base.base_cls] = base
baselist.append(base.base_cls)
else:
base2cls[base] = base
baselist.append(base)
newbases.append(baselist)
# calc MRO and replace them with original base classes
return tuple(base2cls[base] for base in mro.MROMerge(newbases))
def compute_mro(self):
"""Compute the class precedence list (mro) according to C3."""
bases = abstract_utils.get_mro_bases(self.bases(), self.vm)
bases = [[self]] + [list(base.mro) for base in bases] + [list(bases)]
base2cls = {}
newbases = []
for row in bases:
baselist = []
for base in row:
if base.isinstance_ParameterizedClass():
base2cls[base.base_cls] = base
baselist.append(base.base_cls)
else:
base2cls[base] = base
baselist.append(base)
newbases.append(baselist)
# calc MRO and replace them with original base classes
return tuple(base2cls[base] for base in mro.MROMerge(newbases))
