 <span class="type-var">'b</span>)</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 class="type-var">'b</span></span></code></div><div class="spec-doc"><p>Like <code>value_map</code> but the default value is evaluated lazily</p></div></div></div></body></html>
