</a><code><span><span class="keyword">val</span> to_string : <span><a href="../../IStdlib/Pp/index.html#type-env">IStdlib.Pp.env</a> <span class="arrow">&#45;&gt;</span></span> <span><a href="#type-t">t</a> <span class="arrow">&#45;&gt;</span></span> string</span></code></div><div class="spec-doc"><p>convert the attribute to a string</p></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-d_attribute"><a href="#val-d_attribute" class="anchor"></a><code><span><span class="keyword">val<