Re: Check whether an object is an alist

[<tomas@tuxteam.de>]

[-- Attachment #1: Type: text/plain, Size: 1111 bytes --]

On Tue, Sep 17, 2024 at 11:38:46AM +0200, Manuel Giraud via Users list for the GNU Emacs text editor wrote:
> Heime <heimeborgia@protonmail.com> writes:
> 
> > Sent with Proton Mail secure email.
> >
> > On Monday, September 16th, 2024 at 10:29 PM, Heime <heimeborgia@protonmail.com> wrote:
> >
> >> Is there a function that checks whether an object is an alist.
> >> Have only found listp.
> >
> > Because I may have to come up with a solution, I have made this one.
> > Am I missing anything ?
> >
> > (defun torium-alist-p (obj)
> >   "Return t if object OBJ is an association list (alist)."
> >   (and (listp obj)
> >        (not (null obj))
> >        (every (lambda (x)
> >                 (and (consp x)
> >                      (not (null x))))
> >               obj)))
> 
> Looks good to me.  I think it should `cl-every' instead of `every' and
> also, maybe, nil is a valid empty alist.

Unless you'd like to have nil as a possible key (alists allow that,
why not?):

  (setq al '((nil . "I am not") (t . "I am")))
  (alist-get nil al)
  => "I am not"

Cheers
-- 
t

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]