unofficial mirror of help-gnu-emacs@gnu.org
 help / color / mirror / Atom feed
* Make optional argument equal to 0
@ 2007-02-09 11:16 weber
  2007-02-09 12:10 ` Juanma Barranquero
       [not found] ` <mailman.4228.1171023032.2155.help-gnu-emacs@gnu.org>
  0 siblings, 2 replies; 3+ messages in thread
From: weber @ 2007-02-09 11:16 UTC (permalink / raw)
  To: help-gnu-emacs

Hello.
I'd like to set 'arg' to zero when nothing is passed as argument.
Here is a test function:

(defun try-arg (&optional arg)
  "Show which arg is passed."
  (interactive "p")
  (or arg (setq arg 0))
  (message "arg = %d" arg))

If I just call it with M-x try-arg, shouldn't I be geting a 0  ?
I'm getting a 1! :)

Thanks in advance,
weber

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Make optional argument equal to 0
  2007-02-09 11:16 Make optional argument equal to 0 weber
@ 2007-02-09 12:10 ` Juanma Barranquero
       [not found] ` <mailman.4228.1171023032.2155.help-gnu-emacs@gnu.org>
  1 sibling, 0 replies; 3+ messages in thread
From: Juanma Barranquero @ 2007-02-09 12:10 UTC (permalink / raw)
  To: weber; +Cc: help-gnu-emacs

On 9 Feb 2007 03:16:54 -0800, weber <hugows@gmail.com> wrote:

> If I just call it with M-x try-arg, shouldn't I be geting a 0  ?
> I'm getting a 1! :)

Try with (interactive "P"), not "p". With "p" arg is never nil.

                    /L/e/k/t/u

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Make optional argument equal to 0
       [not found] ` <mailman.4228.1171023032.2155.help-gnu-emacs@gnu.org>
@ 2007-02-09 12:22   ` weber
  0 siblings, 0 replies; 3+ messages in thread
From: weber @ 2007-02-09 12:22 UTC (permalink / raw)
  To: help-gnu-emacs

On 9 fev, 09:10, "Juanma Barranquero" <lek...@gmail.com> wrote:
> On 9 Feb 2007 03:16:54 -0800, weber <hug...@gmail.com> wrote:
>
> > If I just call it with M-x try-arg, shouldn't I be geting a 0  ?
> > I'm getting a 1! :)
>
> Try with (interactive "P"), not "p". With "p" arg is never nil.
>
>                     /L/e/k/t/u

Works!
Thanks
weber

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2007-02-09 12:22 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2007-02-09 11:16 Make optional argument equal to 0 weber
2007-02-09 12:10 ` Juanma Barranquero
     [not found] ` <mailman.4228.1171023032.2155.help-gnu-emacs@gnu.org>
2007-02-09 12:22   ` weber

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).