qemu /
qemu /
578cd9329b2c5beac55a8a8c672f96bd40cc183f qapi/schema: declare type for QAPISchemaArrayType.element_type
A QAPISchemaArrayType's element type gets resolved only during .check().
We have QAPISchemaArrayType.__init__() initialize self.element_type =
None, and .check() assign the actual type. Using .element_type before
.check() is wrong, and hopefully crashes due to the value being None.
Works.
However, it makes for awkward typing. With .element_type:
Optional[QAPISchemaType], mypy is of course unable to see that it's None
before .check(), and a QAPISchemaType after. To help it over the hump,
we'd have to assert self.element_type is not None before all the (valid)
uses. The assertion catches invalid uses, but only at run time; mypy
can't flag them.
Instead, declare .element_type in .__init__() as QAPISchemaType
*without* initializing it. Using .element_type before .check() now
certainly crashes, which is an improvement. Mypy still can't flag
invalid uses, but that's okay.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-8-armbru@redhat.com>
1 file changed
