yword">val</span> lines_seq : <span>string <span class="arrow">&#45;&gt;</span></span> <span>string <span class="xref-unresolved">Stdlib</span>.Seq.t</span></span></code></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-concat_iter"><a href="#val-concat_iter" class="anchor"></a><code><span><span class="keyword">val</span> concat_iter : <span><span class="label">sep</span>:string <span class="arrow">&#45;&gt;</span></span> <span><span>string <a href="#type-iter">iter</a></span> <spa