Ppx_deriving_runtime</span>.string</span></code></div></div><div class="odoc-spec"><div class="spec type anchored" id="type-env"><a href="#type-env" class="anchor"></a><code><span><span class="keyword">type</span> env</span><span> = <span><span>(<a href="#type-ident">ident</a> * <span><a href="#type-value">value</a> option</span>)</span> list</span></span></code></div></div><div class="odoc-spec"><div class="spec exception anchored" id="exception-Unknown"><a href="#exception-Unknown" class="anchor"></a><cod