Eric Blake <[email protected]> writes:
> On 10/02/2015 10:48 AM, Markus Armbruster wrote:
>
>>>> Do it the OO-way: QAPISchemaEntity.is_implicit() returns False. Any
>>>> subclass that can have implicitly defined instances overrides it:
>>>> QAPISchemaObjectType.is_implicit() tests for ':' prefix,
>>>> QAPISchemaEnumType.is_implicit() tests for 'Kind' suffix (requires
>>>> outlawing it for user enums, if we don't do it already), and so forth.
>>>
>>> But there's still the issue of filtering by subclass. For the
>>> qapi-types visit_needed() filter, I either write:
>>>
>>> if isinstance(entity, QAPISchemaObjectType) and entity.is_implicit()
>>
>> If is_implicit() is defined on entities, then this shrinks to just
>>
>> entity.is_implicit()
>>
>> because no non-type entity is implicit.
>
> QAPISchemaEnumType is not a subclass of QAPISchemaObjectType, but it can
> indeed be implicit (currently depends on whether its name ends in
> "Kind"). Right now, the code we generate doesn't care about whether
> enums are implicit. But having enum.is_implicit() return False merely
> because it is not an ObjectType feels wrong; if anything, we'd want to
> name it is_implicit_object() if we are only returning whether an object
> is implicit.
You're right; I got confused. I think the most straightforward way to
test "is entity an implicitly defined object type" is the way you wrote
it:
isinstance(entity, QAPISchemaObjectType) and entity.is_implicit()
If we define is_implicit() on entities, either ordering of operands
works.
>>> or what I want to write:
>>>
>>> if entity.is_implicit(QAPISchemaObjectType)
>>
>> I'm not even sure what that's supposed to mean :)
>
> If entity is an implicit ObjectType, return True. If it is implicit but
> not an object (such as an implicit enum), or is not implicit (regardless
> of whether it is an ObjectType), then return False.
>
> And if you don't need filtering by python type, then
> entity.is_implicit() (shorthand for entity.is_implicit(None)) then gives
> the correct answer whether entity is ObjectType or EnumType or something
> else.
I find
isinstance(entity, QAPISchemaObjectType) and entity.is_implicit()
more obvious than
entity.is_implicit(QAPISchemaObjectType)
[...]
