The factorial

When discovering a new programming language, one usually asks how to write the factorial function. Here's a MOOL program for this.

class Integer {
  int value;
  new (int n) {
    this.value := n;
    return n;
  }
  factorial() {
    f := 1;
    i := this.value;
    while (i > 0) repeat {
      f := i * f;
      i := i - 1;
    };
    return f;
  }
  writeln() {
    writeln(this.value);
    return 0;
  }
}
main {
  n := Integer(10);
  f := n.factorial();
  writeln(f);
}