
  Returns a copy of <code>TupleIterator1</code> where the first occurrence of a T
  tuple whose <code>N</code>th element compares equal to <code>Key</code> is replaced with
  <code>NewTuple</code>, if there is such a tuple <code>T</code>.</p>

<h3 class="function"><a name="keysearch-3">keysearch/3</a></h3>
<div class="spec">
<p><tt>keysearch(Key, N, TupleIterator) -&gt; {value, Tuple} | false</tt>
<ul class="definitions"><li><tt>Key = any()</tt></li><li><tt>N = pos_integer()</tt></li><li><tt>TupleIterator 