spawn1.ex

defmodule Spawn1 do
  def greet do
    receive do
      {sender, msg} -> send sender, { :op, "Hello, #{msg}" }
    end
  end
end

# here's a client
#pid = spawn(Spawn1, :greet, [])
#send pid, {self, "World!"}

#receive do
#  { :ok, message} -> IO.puts message
#end