a, 'b, 'c, 'd) <a href="Scanf.html#TYPEscanner">scanner</a></code></pre><div class="info ">
<div class="info-desc">
<p>Same as <a href="Scanf.html#VALbscanf"><code class="code"><span class="constructor">Scanf</span>.bscanf</code></a>, but takes an additional function argument
    <code class="code">ef</code> that is called in case of error: if the scanning process or
    some conversion fails, the scanning function aborts and calls the
    error handling function <code class="code">ef</code> with the format