an></code></div><div class="spec-doc"><p>Like map, but specialized to require <code>f</code> to be an endofunction, which enables preserving <code>==</code> if <code>f</code> preserves <code>==</code> of every value.</p></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-filter_mapi"><a href="#val-filter_mapi" class="anchor"></a><code><span><span class="keyword">val</span> filter_mapi : <span><span><span class="type-var">'a</span> <a href="#type-t">t</a></span> <span class="arrow">&#