John Snow <js...@redhat.com> writes:
> This function is a bit hard to type as-is; mypy needs some assertions to
> assist with the type narrowing.
>
> Signed-off-by: John Snow <js...@redhat.com>
> ---
> scripts/qapi/schema.py | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
> index 043ee7556e6..e617abb03af 100644
> --- a/scripts/qapi/schema.py
> +++ b/scripts/qapi/schema.py
> @@ -997,7 +997,9 @@ def lookup_entity(self, name, typ=None):
def lookup_entity(self, name, typ=None):
ent = self._entity_dict.get(name)
if typ and not isinstance(ent, typ):
return None
> return ent
>
> def lookup_type(self, name):
> - return self.lookup_entity(name, QAPISchemaType)
> + typ = self.lookup_entity(name, QAPISchemaType)
> + assert typ is None or isinstance(typ, QAPISchemaType)
> + return typ
>
> def resolve_type(self, name, info, what):
> typ = self.lookup_type(name)
I figure the real trouble-maker is .lookup_entity().
When not passed an optional type argument, it returns QAPISchemaEntity.
When passed an optional type argument, it returns that type or None.
Too cute for type hints to express, I guess.
What if we drop .lookup_entity()'s optional argument? There are just
three callers:
1. .lookup_type(), visible above.
def lookup_type(self, name):
ent = self.lookup_entity(name)
if isinstance(ent, QAPISchemaType):
return ent
return None
This should permit typing it as -> Optional[QAPISchemaType] without
further ado.
2. ._make_implicit_object_type() below
Uses .lookup_type() to check whether the implicit object type already
exists. We figure we could
typ = self.lookup_entity(name)
if typ:
assert(isinstance(typ, QAPISchemaObjectType))
# The implicit object type has multiple users. This can
3. QAPIDocDirective.run() doesn't pass a type argument, so no change.
Thoughts?
If you'd prefer not to rock the boat for this series, could it still
make sense as a followup?
