/prog/ challenge (S(SKK)(SKK))(S(SKK)(SKK))

The challenge: Implement generators in the favourite language of yours.
Are banned: Language native generators (i.e. FIOC's yield), delimited continuations (sorry, Schemers, that would be too easy).

The test program will be an infinite generator that computes facts, and a loop that takes the first five of them.

The deadline is 17/04/2011 00:00 /prog/time.
The most complete, small and easy to use implementation wins.

If I have the only non anus related entry by deadline, I'm quitting /prog/.

public class Generator {
    int counter;
   
        public Generator(){
        counter = 0;
    }
   
    public int generateNext(){
        return facts(counter++);
    }
   
    public int facts(int n){
        int i, nthFact = 1;
        for(i = 1; i <= n; i++){
            nthFact = nthFact * i;
        }
        return nthFact;
    }
}

public class GeneratorTester {
    public static void main(String args[]){
        int i;
        Generator gen = new Generator();
       
        for(i = 0; i < 5; i++){
            System.out.println(gen.generateNext());
        }
    }
}