href="#val-map" class="anchor"></a><code><span><span class="keyword">val</span> map : <span><span><span class="type-var">'a</span> <span class="xref-unresolved">Base__Option</span>.t</span> <span class="arrow">&#45;&gt;</span></span> <span><span class="label">f</span>:<span>(<span><span class="type-var">'a</span> <span class="arrow">&#45;&gt;</span></span> <span class="type-var">'b</span>)</span> <span class="arrow">&#45;&gt;</span></span> <span><span class="type-var">'b</span> <span class="xref-unresolved"