Sorry, I thought you were talking about the more recent topic, the enum
changes. I see what you're saying now about unions.
My initial proposal was not to change how unions are represented in the
schema, but to update how resolution happens. Right now, we will match a
read schema to a branch by structure for cases where the record has been
renamed. This would apply similar logic, allowing a more generic record to
match.
I wasn't thinking there would be a schema change, though we could certainly
make that happen to standardize this behavior.
rb
On Mon, Apr 18, 2016 at 1:11 PM, Ryan Blue <rb...@netflix.com> wrote:
> Doug, I don't think I understand. Why would this change a union
> representation?
>
> This wouldn't change the schema format, other than to add an attribute to
> enum types that is ignored by older readers. New readers will use that
> attribute to determine which symbol to use when the written symbol is
> unknown.
>
> rb
>
> On Mon, Apr 18, 2016 at 12:59 PM, Doug Cutting <cutt...@gmail.com> wrote:
>
>> Perhaps then its sufficient to only write the new schema format when
>> the new attribute is specified, so existing apps will continue to
>> represent unions as JSON arrays? If so, this should probably be
>> written into the spec.
>>
>> On Mon, Apr 18, 2016 at 12:52 PM, Ryan Blue <rb...@netflix.com.invalid>
>> wrote:
>> > Isn't the problem that these changes aren't compatible right now
>> anyway? If
>> > I need to add an entry to an enum right now, older readers fail when
>> trying
>> > to handle that data. This creates a way to avoid that failure in new
>> > versions.
>> >
>> > On Mon, Apr 18, 2016 at 12:48 PM, Doug Cutting <cutt...@gmail.com>
>> wrote:
>> >
>> >> On Sun, Apr 17, 2016 at 2:00 PM, Matthieu Monsch <mon...@alum.mit.edu>
>> >> wrote:
>> >> > + For unions, we will add an optional catch-all attribute to mark a
>> >> branch as resolution target when no names or aliases match (and come up
>> >> with the corresponding syntax).
>> >>
>> >> Can this be compatible? If you add a new union syntax (e.g.,
>> >> {"type":"union", "branches":[...], "default":...}) then existing
>> >> implementations will not be able to read new data that uses this
>> >> feature.
>> >>
>> >> Doug
>> >>
>> >
>> >
>> >
>> > --
>> > Ryan Blue
>> > Software Engineer
>> > Netflix
>>
>
>
>
> --
> Ryan Blue
> Software Engineer
> Netflix
>
--
Ryan Blue
Software Engineer
Netflix
