[kernelbandwidth]

I had not really considered the design patterns of the culture vs the design patterns of the language; this is a very good point.

> I can pretty much prove that they don't: https://github.com/thejerf/suture It's the process that needs monitoring, and that process may have 0-n ways to communicate. But that's not a criticism of Erlang, as I think that's actually what it does and it just happens to have a fused message box per process.

One, very neat library. Two, while I agree this proves the point that the actor model is not needed in the language to build a process supervisor, I think that your Go Supervisor looks a lot like an actor, at least in the way Erlang/Elixir uses them. From what I can see, the Supervisor itself works by looping over channel receives and acts on it. The behavior of the Supervisor lives in a separate goroutine, and you pass around an object that can send messages to this inner behavior loop via some held channels. So basically the object methods provide a client API and the inner goroutine plays the role of a server, in the same separate of responsibilities that gen_* uses.

If we squint a little bit, actors actually look a lot like regular objects with a couple of specific restrictions: all method calls are automatically synchronized at the call/return boundaries (in Go, this is handled explicitly by the channel boundaries instead), no shared memory is allowed, and data fields are always private. I'm sure this wouldn't pass a formal description, but this seems like a pragmatically useful form.

I agree that Go is less actor-oriented than Erlang/Elixir, but given how often I've seen that pattern you used in the Supervisor (and it's one I have also naturally used when writing Go) I'd argue that "Actor" is a major Go design pattern, even if it doesn't go by that name. The difference then, is the degree to how often one pulls out the design pattern. I think the FP aspect pushes Erlang/Elixir in that direction more, as this "Actor" pattern has a second function there -- providing mutable state -- that Go allows more freely.

This discussion has really made me think, thanks. I think you're right that actor-like features are valuable and that the Actor Model in the everything-is-an-actor is not itself the value (or even a positive).