GNU Info

(emacs-lisp-intro.info)Void Function

---

Next: Void Variable Prev: fill-column Example Up: Variables

---

Enter node , (file) or (file)node

Error Message for a Symbol Without a Function
---------------------------------------------

   When we evaluated `fill-column' to find its value as a variable, we
did not place parentheses around the word.  This is because we did not
intend to use it as a function name.

   If `fill-column' were the first or only element of a list, the Lisp
interpreter would attempt to find the function definition attached to
it.  But `fill-column' has no function definition.  Try evaluating this:

     (fill-column)

In GNU Emacs version 21, you will create a `*Backtrace*' buffer that
says:

     ---------- Buffer: *Backtrace* ----------
     Debugger entered--Lisp error: (void-function fill-column)
       (fill-column)
       eval((fill-column))
       eval-last-sexp-1(nil)
       eval-last-sexp(nil)
       call-interactively(eval-last-sexp)
     ---------- Buffer: *Backtrace* ----------

(Remember, to quit the debugger and make the debugger window go away,
type `q' in the `*Backtrace*' buffer.)

   In GNU Emacs 20 and before, you will produce an error message that
says:

     Symbol's function definition is void: fill-column

(The message will go away away as soon as you move the cursor or type
another key.)