John Snow <js...@redhat.com> writes:
> Optional[List] is clunky; an empty sequence can more elegantly convey
> "no variants". By downgrading "List" to "Sequence", we can also accept
> tuples; this is useful for the empty tuple specifically, which we may
> use as a default parameter because it is immutable.
>
> Signed-off-by: John Snow <js...@redhat.com>
> ---
> scripts/qapi/introspect.py | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py
> index 649225988d1..e4d31a59503 100644
> --- a/scripts/qapi/introspect.py
> +++ b/scripts/qapi/introspect.py
> @@ -247,13 +247,13 @@ def _use_type(self, typ: QAPISchemaType) -> str:
> return self._name(typ.name)
>
> @staticmethod
> - def _gen_features(features: List[QAPISchemaFeature]
> + def _gen_features(features: Sequence[QAPISchemaFeature]
> ) -> List[Annotated[str]]:
> return [Annotated(f.name, f.ifcond) for f in features]
>
> def _gen_tree(self, name: str, mtype: str, obj: Dict[str, object],
> ifcond: Sequence[str],
> - features: Optional[List[QAPISchemaFeature]]) -> None:
> + features: Sequence[QAPISchemaFeature] = ()) -> None:
> """
> Build and append a SchemaInfo object to self._trees.
>
> @@ -261,7 +261,8 @@ def _gen_tree(self, name: str, mtype: str, obj: Dict[str,
> object],
> :param mtype: The entity's meta-type.
> :param obj: Additional entity fields, as appropriate for the
> meta-type.
> :param ifcond: Sequence of conditionals that apply to this entity.
> - :param features: Optional features field for SchemaInfo.
> + :param features: Optional, The features field for SchemaInfo.
Downcase "The".
> + Will be omitted from the output if empty.
> """
> comment: Optional[str] = None
> if mtype not in ('command', 'event', 'builtin', 'array'):
> @@ -298,7 +299,7 @@ def _gen_variant(self, variant: QAPISchemaVariant
>
> def visit_builtin_type(self, name: str, info: Optional[QAPISourceInfo],
> json_type: str) -> None:
> - self._gen_tree(name, 'builtin', {'json-type': json_type}, [], None)
> + self._gen_tree(name, 'builtin', {'json-type': json_type}, [])
>
> def visit_enum_type(self, name: str, info: Optional[QAPISourceInfo],
> ifcond: Sequence[str],
> @@ -316,7 +317,7 @@ def visit_array_type(self, name: str, info:
> Optional[QAPISourceInfo],
> element_type: QAPISchemaType) -> None:
> element = self._use_type(element_type)
> self._gen_tree('[' + element + ']', 'array', {'element-type':
> element},
> - ifcond, None)
> + ifcond)
>
> def visit_object_type_flat(self, name: str, info:
> Optional[QAPISourceInfo],
> ifcond: Sequence[str],
Marginal by itself. Might be worth it as part of a more general move
away from Optional[List[...]]. See also next patch.
