Declare, but don't initialize the "members" field with type List[QAPISchemaObjectTypeMember].
This simplifies the typing from what would otherwise be Optional[List[T]] to merely List[T]. This removes the need to add assertions to several callsites that this value is not None - which it never will be after the delayed initialization in check() anyway. The type declaration without initialization trick will cause accidental uses of this field prior to full initialization to raise an AttributeError. (Note that it is valid to have an empty members list, see the internal q_empty object as an example. For this reason, we cannot use the empty list as a replacement test for full initialization and instead rely on the _checked/_checking fields.) Signed-off-by: John Snow <js...@redhat.com> --- scripts/qapi/schema.py | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py index a459016e148..947e7efb1a8 100644 --- a/scripts/qapi/schema.py +++ b/scripts/qapi/schema.py @@ -20,7 +20,7 @@ from collections import OrderedDict import os import re -from typing import List, Optional +from typing import List, Optional, cast from .common import ( POINTER_SUFFIX, @@ -457,7 +457,7 @@ def __init__(self, name, info, doc, ifcond, features, self.base = None self.local_members = local_members self.variants = variants - self.members = None + self.members: List[QAPISchemaObjectTypeMember] self._checking = False def check(self, schema): @@ -474,7 +474,7 @@ def check(self, schema): self._checking = True super().check(schema) - assert self._checked and self.members is None + assert self._checked seen = OrderedDict() if self._base_name: @@ -491,7 +491,10 @@ def check(self, schema): for m in self.local_members: m.check(schema) m.check_clash(self.info, seen) - members = seen.values() + + # check_clash is abstract, but local_members is asserted to be + # List[QAPISchemaObjectTypeMember]. Cast to the narrower type. + members = cast(List[QAPISchemaObjectTypeMember], list(seen.values())) if self.variants: self.variants.check(schema, seen) @@ -524,11 +527,9 @@ def is_implicit(self): return self.name.startswith('q_') def is_empty(self): - assert self.members is not None return not self.members and not self.variants def has_conditional_members(self): - assert self.members is not None return any(m.ifcond.is_present() for m in self.members) def c_name(self): -- 2.43.0