Re: [External] : Handling nil values in optional argument

[Heime <heimeborgia@protonmail.com>]

On Friday, July 12th, 2024 at 4:37 PM, Michael Heerdegen via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org> wrote:

> Drew Adams drew.adams@oracle.com writes:
> 
> > Instead, your code can use something other than nil for the value that
> > you pass as an explicit argument. It can use the singleton list
> > (nil), for example.
> 
> 
> Alternatively one can give the defun an &rest argument list and look at
> the length of the specified list in the body. The argument variables
> would have to be assigned in the body. Use an advertised calling
> convention to get argument name support back for eldoc etc.
> 
> I guess that's more or less what's cl-defun also does. So one can also
> use cl-defun. Or just do as Drew said.
> 
> 
> Michael.

Can you show an example of using &rest for the specified purpose.