Provide full support for proto3

[oubiwann]

Tasks:

• Add proto3 examples
• Add proto3 tests
• Add proto3 support for default value in enums - Support proto3 default value for enums #30
• Add support for extracting the syntax of any given message
• Update Travis CI config to support proto3 on Travis builds (Travis Ubuntu containers currently only support 3)

[oubiwann]

There's a proto3 example here:

• https://github.com/google/protobuf/blob/master/examples/addressbook.proto

Update: Added.

[oubiwann]

The more I read about proto3, the less I like it :-( The changes were pretty drastic, from the perspective of schema-based data applications (or RPC services). I may end up back-burnering this task. I'd accept a PR for a good solution that didn't effect the usability of proto2 ...

[oubiwann]

I guess I should claify that last comment:

1. I'm still working on supporting proto3 ;-)
2. The comment was made after exploring the possibility of converting everything to proto3, since it and proto2 are wire-compatible ...
3. The explorations were a dismal failure, and I did a lot of reading to learn more about all the changes between versions and their implications, in an effort to determine a level of effort in moving everything in this project to proto3 ...

On a side note, I did come across Cap'n Protocol (by the author of Protocol Buffers v2), and that looks really nice; too bad Google won't adopt it :-(

[mattyulrich]

This is a great expansion of the flatland impl. The interface is simple as expected. Thanks for the work on this!

I'm experiencing something that may be attributable to this issue/epic - when I deserialize proto3 schemas that have enums with 0 vals, the enum seems to just drop out of the message. Is this expected until proto3 is fully supported?

Thanks again for the library!

[smessems]

Hi, is there any update?

[oubiwann]

Sadly, no :-(

I don't suspect I'll have the time to work on proto3 any time in the near future, so this will likely need to be a community contribution/PR.

It's an interesting problem to tackle; wish I had more availability for it.

[smessems]

Thanks. Would it be possible to maybe lay out some info you gained while investigating this?