&nbsp;&nbsp;&nbsp;string&nbsp;<span class="keywordsign">-&gt;</span><br>
&nbsp;&nbsp;&nbsp;&nbsp;(<span class="constructor">Build_path_prefix_map</span>.map,&nbsp;<span class="constructor">Build_path_prefix_map</span>.error_message)<br>
&nbsp;&nbsp;&nbsp;&nbsp;<span class="constructor">Pervasives</span>.result<br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;rewrite_opt&nbsp;:<br>
&nbsp;&nbsp;&nbsp;&nbsp;<span class="constructor">Build_path_prefix_map</span>.map&nbsp;<span class="keywordsign">-&gt;</sp