<span class="keywordsign">-&gt;</span>&nbsp;pos:int&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;len:int&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;bytes<br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;sub_string&nbsp;:&nbsp;bytes&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;pos:int&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;len:int&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;string<br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;extend&nbsp;:&nbsp;bytes&nbsp;<span class