Is there a way to use a keyword as a function in Common Lisp, as one does in Clojure? <p>In Clojure one can write</p> <pre><code>(:foo {:foo 3 :bar 5}) </code></pre> <p>which evaluates to 3. Is there any way to extend Common Lisp so that a keyword will act as a function that looks itself up?</p>