s="keyword">val</span> fold_mapi : <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> <span>init:<span class="type-var">'a</span></span> <span>&#45;&gt;</span> <span>f:<span>(<a href="index.html#type-key">key</a> <span>&#45;&gt;</span> <span class="type-var">'a</span> <span>&#45;&gt;</span> <a href="index.html#type-value">value</a> <span>&#45;&gt;</span> <span class="type-var">'a</span> * <a href="index.html#type-value">value</a>)</span></span> <span>&#45;&gt;</span> <span class="type-var">'a</span> *