Erlang Ring Benchmark Part 2

Using list comprehensions - results in more compact code.

-module(ring3).
-include("debug.hrl").
-export([start/2]).
%% ring benchmark using lists methods
start(N, M) ->
    io:format("Starting ring benchmark on pid=~p, N = ~p, M = ~p.~n", [self(), N, M]),
    statistics(wall_clock),
    statistics(runtime),
    Last = lists:foldl(fun (X, Pid) -> 
        spawn(fun () -> loop(X, Pid) end) end, self(), lists:seq(N-1, 1, -1)),    
    lists:foreach(fun (X) -> send(X, Last) end, lists:seq(M-1, 0, -1)),
    {_, WC} = statistics(wall_clock),
    {_, RT} = statistics(runtime),
    io:format("Done running ring benchmark in Wall Clock = ~p, Runtime = ~p.~n", [WC, RT]).

send(X, Pid) ->
    ?DEBUG("sending X=~p to ring.~n", [X]),
    Pid ! X,
    receive
 Xm -> ?DEBUG("main node done waiting for x = ~p.~n", [Xm])
    end.

loop(Nth, Pid) ->
    receive
 X when X =:= 0 -> 
     ?DEBUG("~p dying.~n", [Nth]),
     Pid ! X;
 X -> 
     ?DEBUG("~p got message.~n", [Nth]), 
     Pid ! X,
     loop(Nth, Pid)
    end.