Re: Nested sit-for's

["Juanma Barranquero" <lekktu@gmail.com>]

(From an old thread)

On 8/18/06, Richard Stallman <rms@gnu.org> wrote:

> To enable that, I added a function current-idle-time.

Is there any reason for `current-idle-time' returning nil when Emacs
is not idle, instead of (0 0 0)?

That return value is not documented, and though there are time
functions that understand nil as (0 0 0):

 ELISP> (timer-set-time (timer-create) nil)
 [t nil nil 0 nil nil nil nil]

there are others that do not:

 ELISP> (time-add (current-idle-time) '(0 0 0))
 *** Eval error ***  Wrong type argument: number-or-marker-p, nil

             Juanma