 class="code">ib</code> to read the
      next argument. The input function <code class="code">ri</code> must therefore have type
      <code class="code"><span class="constructor">Scanning</span>.in_channel&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;<span class="keywordsign">'</span>a</code> and the argument read has type <code class="code"><span class="keywordsign">'</span>a</code>.</li>
<li><code class="code">{&nbsp;fmt&nbsp;%}</code>: reads a format string argument. The format string
      read mu