title: get the absolute path of a file without extension
body: <p>To get the absolute file path without extension in a buffer, e.g. <code>/home/alice/hello.cpp</code> -> <code>/home/alice/hello</code>, the following code works</p>
  
  <pre><code>(concat (file-name-directory (buffer-file-name)) (file-name-base (buffer-file-name)))
  </code></pre>
  
  <p>But it looks too verbose. Is there a much elegant way or a direct function for this?</p>