ring.erl

-module(geometry).
-export([startN/1]).

ringAgent(Next) ->                 
    receive
        {next, N} when Next =:= undefined ->
            ringAgent(N);
        kill -> Next ! kill;       
        M ->
            io:format("~p received ~p~n", [self(), M]),
            Next ! M,
            ringAgent(Next)       
    end.

startN(1, Pid) -> Pid ! {next, spawn(geometry, ringAgent, [Pid])}, Pid; 
startN(N, Pid) ->
    startN(N-1, spawn(geometry, ringAgent, [Pid])).

startN(N) ->
    startN(N, undefined).