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erlangelixirerlang-otpgen-server

Why is the word "cast" used to handle async message in a GenServer?

Why, in Erlang/Elixir, is the asynchronous GenServer handler named with handle_cast? The handle_ part is obvious, but why the word cast?

The only thing I can think of is that it is akin to just throwing something out there (as in casting a net) vs calling out for something and waiting for a reply.

Solution

  • I think you answered the question yourself, already.

    The only thing I can think of is that it is akin to just throwing something out there (as in casting a net) vs calling out for something and waiting for a reply.

    However, apart from asking the erlang creators, we can only speculate.

    Cast: to cause to move or send forth by throwing

    Basically, you're tossing a message to the GenServer, not expecting something in response.

    Call: to make a request or demand

    I think this is something that expects a response. If you call to someone you expect them to answer.