how to get a actor pid by it's name

[zylikedream]

like whereis function in erlang

[halturin]

Ergo doesnt have such feature. Why do you need it?

[yordis]

@halturin normally we do the whereis to find the PID where it is, ideal when multi-node https://hexdocs.pm/elixir/GenServer.html#whereis/1 So most people do that "safety" net before sending the message and crash

[halturin]

In Ergo, sending to an unknown process doesn’t cause a crash.

• Local case: you’ll get the error "unknown process".
• Remote case: it depends..
  • For asynchronous messaging, you may want to use SendImportant to ensure that your message has actually been delivered to the target process’s mailbox. Otherwise, you’ll get the same "unknown process" error as if you had sent it locally.
  • For a call request to a remote node, you’ll get a timeout error.

So in any case, I still don’t see a strong reason for the existence of a whereis feature. 🙂

[zylikedream]

For example server has many users. When I want to notify a user to exit, since process.SendExit can only pass PID, but I only have its userid, what should I do in this case?

[halturin]

Your example is more like application level scenario so has to be solved at that level. Besides, theexit signal can be ignored (see TrapExit in the act.Actor).

[zylikedream]

It is indeed an application layer scenario, but if there is a whereis function, the application layer will be very simple to handle. By the way, I think it is very simple for ergo to provide a whereis function