Re: using command-error-function in emacspeak

[Stefan Monnier]

> (add-function command-error-function something) ;; forgive me wrong syntax
> here should do the same as
> (setq command-error-function something)
> in case when command-error-function is nil beforehand.

But that can't be right.
E.g.

   (add-function :before command-error-function
                 (lambda (&rest _ignore)
                   (cl-incf command-error-function-counter)))

Should not affect Emacs's behavior other than to keep a counter of calls
to command-error-function.  But

  (setq command-error-function
        (lambda (&rest _ignore) (cl-incf command-error-function-counter))

will not do that, since it will instead silence all the
command-error messages.
        

        Stefan