title: Company Backends in GNU Emacs
body: <p>In Emacs, I have installed the MELPA <code>company-irony-c-header</code> package. I then did some research on the web, and apparently in order to configure the package, what I took to mean "activating" it, I had to add this:</p>
  
  <pre><code>(defun company-my-backend (command &amp;optional arg &amp;rest ignored)
    (interactive (list 'interactive))
    (case command
      (interactive (company-begin-backend 'company-my-backend))
      (prefix (when (looking-back "foo\\&gt;") (match-string 0)))
      (candidates (when (equal arg "foo") (list "foobar" "foobaz" "foobarbaz")))
      (meta (format "This value is named %s" arg))))
  </code></pre>
  
  <p>into something called a "<strong>back-end</strong>" (with <code>foo</code> standing for whatever my filename was). I have absolutely no idea what a back-end is, or how to use it. Any help would be greatly appreciated.</p>