ahead of the loop in this program:
</p>

<pre>
n := 0
for e := list; e != nil; e = e.next {
	n++
}
i := *p
*q = 1
</pre>

<p>
If <code>list</code> pointed to a cyclic list,
then the original program would never access <code>*p</code> or <code>*q</code>,
but the rewritten program would.