Subject: bug#47427: [External] : Re: bug#47427: 26.3; 1. Please define a built-in predicate `plistp', 2. wrong type wrong-type-argument error

From: Drew Adams <[email-masked]>
Date: Sun, 28 Mar 2021 18:25:31 +0000

> The backtrace has "abc"; the code example does not.

Yeah, sorry; typo.

> > On the other hand, a probably more important question
> > is the cost of getting the length of the list.  That
> > would be my main hesitation to say we should really
> > have a `plistp' predicate.
> 
> Why?  It's not like we'd use it for anything much.

I meant that if we really had an (accurate) error msg
saying that the plist wasn't proper then in order to
test that for each `plist-put' or whatever we'd have
to traverse every plist argument, to see if it really
is proper.

To test that `(a b c)' isn't a proper plist we'd need
to check that the number of elements is even.

We could of course have a `plistp' predicate without
using it to test during `plist-put' etc.