[Programma non testato]


-module(sumf).
-export([sum/2,compute/3,coll/3,idd/1]).


sum (F,N)              ->     Collector = spawn(sumf,coll,[N,0,self()]),

                          [spawn(sumf,compute,[F,X,Collector]) || X <- lists:seq(1,N) ],
                     
                           receive 
                                   {Collector,Res} -> Res
                           end.


compute (F,X,Collector) -> Collector!F(X).


coll (N,Partial,PID)    ->  if 
                             N=:=0 -> PID!{self(),Partial};
                             true   -> receive Fn -> coll(N-1, Partial+Fn,PID) end
                         end.

idd (N) -> N.