title: What does #[...] mean in emacs-lisp?
body: <p>I am puzzled by the expression </p>
  
  <pre><code>#[nil "\300\207"
        [nil]
        1]
  </code></pre>
  
  <p>as a value of <code>skeleton-pair-filter-function</code>. </p>
  
  <p>Is this an alternative way of writing function in elisp? Or lisp in general?</p>
  
  <p>Thanks.</p>