(defun what-face (pos)
  "Find out which face the current position uses"
  (interactive "d")
  (let ((face (or (get-char-property (point) 'read-face-name)
                  (get-char-property (point) 'face))))
    (if face
        (message "Face: %s" face)
      (message "No face at %d" pos))))

(defun my-comp-finish-function (buf str)
  "Don't show compilation window if everything went ok"
  (if (string-match "exited abnormally" str)
      ;; there were errors
      (message "compilation errors, press C-x ` to visit")
    ;; no errors, make the compilation window go away in 0.5 seconds
    (run-at-time 0.5 nil 'delete-windows-on buf)
    (message "NO COMPILATION ERRORS!")))

(defun show-whitespace ()
  (interactive)
  (whitespace-mode t))