protocol-buffersproto3

Can I define an ordered mixed message array in proto3?

I want to define in proto3 an ordered list of unrelated classes (messages) like this:

  1. Frog
  2. Dirt
  3. Air
  4. Computer 1
  5. Computer 2
  6. Politics

Is it possible? I can also live with having a base class (base message) if that exists in proto3... Its not clear to mean if the feature set of proto3 allows this. Thanks!

Solution

  • The typical way of representing this would be

    message Wrapper {
    oneof Thing {
        Frog frog = 1;
        //...
        Politics politics = 6;
    }
}

    and use repeated Wrapper for the list/array. There is no one-step repeated oneof.

    Alternatively, you could just use

    repeated Frog frogs = 1;
//...
repeated Politics politics = 6;

    However this second layout cannot preserve the order between different kinds of element.