PL/SQL Regular expression not working
<p>I have the following code:</p>

<pre><code>declare
  l_input      clob;
  l_output     clob;
  function check_this_regex(
    io_str    in out clob
    ,o_found  out clob
  ) return boolean
  is
    l_match   clob;
  begin
    dbms_output.put_line('Matching against -&gt;' || io_str || '&lt;-');
    l_match := regexp_substr(io_str, '"((y)*)"');

    if l_match is null then
      return false;
    end if;

    o_found := l_match;
    return true;
  end;
begin
  l_input := to_clob('x');
  dbms_output.put_line('l_input-&gt;' || l_input || '&lt;-');
  if (check_this_regex(l_input, l_output)) then
     dbms_output.put_line('Found: ' || l_output);
  else
     dbms_output.put_line('Not found');
  end if;
end;
</code></pre>

<p>Why does this output <code>Found</code>?</p>