(defun completing-read-alist (prompt collection &rest args)
  (let* ((coll (mapc (lambda (el)
                       (if (and (consp el) (cdr el))
                           (setf (car el)
                                 (propertize (format "%s" (car el)) :values (cdr el)))
                         el))
                     collection))
         (input (apply 'completing-read prompt coll args)))
(or (get-text-property 0 :values input) input)))