setree.expression;</code></dt><dt class="spec value" id="val-unit"><a href="#val-unit" class="anchor"></a><code><span class="keyword">let</span> unit: ?&#8288;loc:Ast_406.Ast_helper.loc <span>=&gt;</span> unit <span>=&gt;</span> Ast_406.Parsetree.expression;</code></dt><dt class="spec value" id="val-should_rewrite"><a href="#val-should_rewrite" class="anchor"></a><code><span class="keyword">let</span> should_rewrite: Stdlib.ref(bool);</code></dt><dt class="spec value" id="val-expr"><a href="#val-expr" class