title: gensym in Racket
body: <p>I know gensym can generate symbols, but it seems that there is a global counter there with the base, which can be very large, for example, <code>(define s (gensym 's))</code> the s can end up with <code>s12345</code>.
  I am wondering whether there is a way to reset the counter, where the number generated can be small?like <code>s14</code>?</p>