(defun smart-tab () ;; implement a smarter TAB
  "This smart tab is minibuffer compliant: it acts as usual in the minibuffer.
 Else, if mark is active, indents region. Else if point is at the end of a symbol, expands it.
 Else indents the current line."
  (interactive)
  (if (minibufferp)
      (unless (minibuffer-complete)
        (auto-complete)) ;; use auto-complete
        ;; (hippie-expand nil)) ;; use hippie-expand
        ;; (dabbrev-expand nil)) ;; use dabbrev-expand
    (if mark-active
        (indent-region (region-beginning)
                       (region-end))
      (if (looking-at "\\_>")
          (auto-complete) ;; use auto-complete
          ;; (hippie-expand nil)) ;; use hippie-expand
          ;; (dabbrev-expand nil) ;; use dabbrev-expand
        (indent-for-tab-command)))))