"><a href="#val-rindex_opt" class="anchor"></a><code><span><span class="keyword">val</span> rindex_opt : <span>string <span class="arrow">&#45;&gt;</span></span> <span>char <span class="arrow">&#45;&gt;</span></span> <span>int option</span></span></code></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-to_seqi"><a href="#val-to_seqi" class="anchor"></a><code><span><span class="keyword">val</span> to_seqi : <span>string <span class="arrow">&#45;&gt;</span></span> <span><span>(int * 