Echo process with IO.write compatibility.

examples/07-processes/echo.exs

@@ -0,0 +1,22 @@
+defmodule Echo do
+  def start do
+    {:ok, echo_pid} = Task.start fn -> loop() end
+    Process.register(echo_pid, :echo)
+    echo_pid
+  end
+
+  def loop do
+    receive do
+      {:io_request, caller, reply_as, msg} ->
+        IO.inspect msg
+        send(caller, {:io_reply, reply_as, msg})
+        loop()
+      msg ->
+        IO.inspect msg
+        loop()
+    end
+  end
+end
+
+Echo.start
+# IO.write(:echo, "hello")