[naasking]

Protobuf does not do this via a typed interface, but via runtime checking.

[joshuamorton]

You can't statically typecheck deserialized data. You must validate that deserislized value matches the schema, and you can only do so at runtime.

In other words, proto has a typed interface, but you must runtime check that a given bag of bytes conforms to that typed interface.

This is true for any io.

[naasking]

> You must validate that deserislized value matches the schema, and you can only do so at runtime

I assume you mean serialised data, not deserialized. And yes, deserializing includes type checking. The point is that this happens once and the need for a separate API for dynamic data shouldn't be needed.

[joshuamorton]

What do you mean by a separate api for dynamic data?

The data under discussion isn't "dynamic", it's still static, it just isn't known to the schema in question at runtime (since it's only known to a different schema). That means you can't access it by name, since the field names aren't known.