Why does Process.flag look like an OOP type method?

Questions / Help
21

Perhaps here is something else to clarify. When you call Process.link/1 you are just calling a function, you are not sending a message to another process – just like when you call Enum.join/1 or String.trim/1. Granted, in those functions you have to pass a data structure in to them, but you are not sending a message. Yes, for functions in the Process module, self is implied, and I can see how these are somewhat of a special case, but why would you force the caller to send self, but immediately reject it if it’s not self, when you can just get self yourself?

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22

We do this in registry.ex, or this not the same thing?

@doc false
  def register_name({registry, key}, pid) when pid == self() do
    case register(registry, key, nil) do
      {:ok, _} -> :yes
      {:error, _} -> :no
    end
  end
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23

That’s interesting. I’ve not dug into the internals of Registry yet. I assume there is another function clause that does not have the when pid == self though.

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24

I do not see another register_name function in the module.

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25

Thanks everyone for taking the time to respond to my questions. It definitely helps!

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26

register_name/2 is a callback that’s required to use alternative process registries with gen_server, etc., so Elixir has no control over its signature. Some process registries (such as global) do support registering processes other than self().

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27

Haha, interesting topic. Maybe because processes in elixir/erlang are a little bit like objects in OOP, and I’m not joking. :stuck_out_tongue_winking_eye:

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28

It is not a maybe. Processes are what OOP should have been if you listen to Alan Kay.

But somewhere in the middle, people decided to use Simula constructs.

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