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

From: Lars Ingebrigtsen <[email-masked]>
Date: Sun, 28 Mar 2021 19:15:43 +0200

Drew Adams <[email-masked]> writes:

>> >  (plist-put (list 'a 'b 'c) "a" 42)
>> >
>> > Debugger entered--Lisp error: (wrong-type-argument plistp (a b c))
>> >   plist-put((a b c) "abc" 42)
>> >   eval((plist-put (list (quote a) (quote b) (quote c)) "abc" 42))
>> >
>> > That's all fine and dandy, except that there is no predicate `plistp'.
>> 
>> The backtrace there doesn't seem to be a result of the example form,
>
> What do you mean by that?

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

> 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.  

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no