Eric Blake <[email protected]> writes:
> On 10/02/2015 02:54 AM, Markus Armbruster wrote:
>> Eric Blake <[email protected]> writes:
>>
>>> A future patch will enable deferred error detection in the
>>> various QAPISchema*.check() methods (rather than the current
>>> ad hoc parse checks).
>>
>> What's "deferred" about them?
>
> With ad hoc parse checks, we validate the .json before calling
> QAPISchemaEntity constructors. With QAPISchemaEntity.check(), the
> constructor is called on various strings, but the strings may not
> resolve; we don't know about the problem until check() is called.
I guess I'd say something like
A future patch will move some error checking from the parser to the
various QAPISchema*.check() methods. These run only after parsing
completes.
>>
>> Perhaps simply: A future patch will move error checking into the various
>> QAPISchema*.check() methods.
>>
>>> But that means the user can request
>>> a QAPI entity that will only fail validation after it has
>>> been initialized.
>>
>> I'm not sure I get this sentence.
>
> Trying to point out that while pre-patch, the check() method was only
> run on well-formed entities, now post-patch it can raise errors that we
> chose not to detect prior to __init__ time.
>
>>> RFC: I used a class-level static flag to track whether we expected
>>> 'info is None' when creating a QAPISchemaEntity. This is gross,
>>> because the flag will only be set on the first QAPISchema() instance
>>> (it works because none of our client scripts ever instantiate more
>>> than one schema). But the only other thing I could think of would
>>> be passing the QAPISchema instance into the constructor for each
>>> QAPISchemaEntity, which is a lot of churn. Any better ideas on how
>>> best to do the assertion, or should I just drop it?
>>>
>>> Signed-off-by: Eric Blake <[email protected]>
>>
>> I'd check in QAPISchema._def_entity().
>
> Ah, instead of an assert in QAPISchemaEntity.__init__() (which requires
> a leaky abstraction), instead write the assert into QAPISchema (so the
> flag can now be instance-local). Makes sense; I'll play with the idea.
:)
