Not only `required` documents the intention, it helps us writing less validation code.
For example, look at `Entity` fields and motivation behind making them required [1]. Before making this change we were discussing the alternative `optional` + extra validation, but decided to go the `required` way because it is *less* code. I understand arguments against `required` (though downgrade to `optional` is possible with our support policy). We will have to go through the change `required` -> `optional` anyway—and write a bunch of validation code—if we decide to move to proto3. I agree with the suggestion to be mindful about adding new required fields. However, in certain cases I still see value from using them and would exploit this possibility while we are still on proto2. [1] https://github.com/apache/mesos/blob/30d703fe81eacf64e9d84503074579cf5667bea1/include/mesos/authorizer/acls.proto On Thu, Jun 23, 2016 at 10:17 PM, Joris Van Remoortere <[email protected]> wrote: > I think it would be great to comment in place e.g. `/* required */ optional > <field>`. > It's difficult enough as is to extract the semantics out of the current > Protos. The required helped document which fields were actually required. > > — > *Joris Van Remoortere* > Mesosphere > > On Thu, Jun 23, 2016 at 2:40 AM, Jie Yu <[email protected]> wrote: > > > +1 > > > > Proto3 killed 'required' keyword. > > > > On Wed, Jun 22, 2016 at 5:15 PM, Jay JN Guo <[email protected]> > wrote: > > > > > > > > > > > Hi, > > > > > > I find marking protobuf field as 'required' sometimes causing trouble: > > > serializing a message without filling up required field generates > errors > > > and this is hard to change due to backwards compatibility. And this > > message > > > type is actually discouraged by protobuf: > > > > > > > > > https://developers.google.com/protocol-buffers/docs/proto#specifying-field-rules > > > > > > So is there a particular reason we are doing it? I would suggest to use > > > optional and repeated onwards if possible and add more verification > logic > > > instead. > > > > > > /Jay > > > > > >
