% Erlang version of a Prime Number Finder
% haplo@mindstab.net
-module(primes).
-author('haplo@mindstab.net').
-export([primes/1]).

check(I, Cnt, Max) when I < Max, (Cnt rem I) == 0 -> 0;
check(I, Cnt, Max) when I < Max -> check(I+2, Cnt, Max);
check(I, Cnt, Max) -> 1.

primes([Max]) -> primes(3, list_to_integer(atom_to_list(Max)), 2, 4);
primes(Max) -> primes(3, Max, 2, 4).

primes(Cnt, Max, Sq, Sqm) when Cnt < Max, Cnt >= Sqm -> 
	primes(Cnt, Max, Sq+1, (Sq+1)*(Sq+1)); 
primes(Cnt, Max, Sq, Sqm) when Cnt < Max -> 
		case check(3, Cnt, Sq) of
			0 -> 0;
			C  -> io:format("~p\n", [Cnt])
		end,
		primes(Cnt+2, Max, Sq, Sqm)
	;
primes(Cnt, Max, Sq, Sqm) -> init:stop().