LFE tutorial 20 - registered process names

lfe-tut-20.lfe

(defmodule lfe-tut-20
  (export (start 0)
          (ping 1)
          (pong 0)))

(defun ping
  ([0]
   (! 'pong 'finished)
   (lfe_io:format "ping finished~n" ()))
  ([n]
   (! 'pong (tuple 'ping (self)))
   (receive
     ('pong
      (lfe_io:format "ping received pong~n" ())))
   (ping (- n 1))))

(defun pong []
  (receive
    ('finished
     (lfe_io:format "pong received finished, pong finished~n" ()))
    ((tuple 'ping ping-pid)
     (lfe_io:format "pong received ping~n" ())
     (! ping-pid 'pong)
     (pong))))

(defun start []
  (let ((pong-pid (spawn 'lfe-tut-20 'pong ())))
    (register 'pong pong-pid)
    (spawn 'lfe-tut-20 'ping '(3))))