bsp;&nbsp;&nbsp;<span class="keyword">type</span>&nbsp;parse_result&nbsp;=&nbsp;<span class="constructor">Ok</span>&nbsp;<span class="keywordsign">|</span>&nbsp;<span class="constructor">Parse_failed</span>&nbsp;<span class="keyword">of</span>&nbsp;exn<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;parse_no_error&nbsp;:<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;string&nbsp;<span class="keywordsign">-&gt;</span><br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<spa