Re: [Gcl-devel] fixes to tailp and nconc

[Peter Wood]

On Mon, Jan 27, 2003 at 08:14:36PM -0600, Paul F. Dietz wrote:
> Camm Maguire wrote:
> 
> >>nconc can take a dotted list.  This means GCL is in error here:
> >>
> >>(nconc '(a . b) 'c) ==> signals an error saying 'b is not a list.--
> >>should be '(a . c)
> >>
> >>Also tailp must return T for nil and a proper list. GCL is doing this:
> >>
> >>(tailp nil '(a b c)) ; ==> nil -- should be T
> >>
> >>I can't submit a diff, since my list.d also contains other changes,
> >>but I think this is the relevant code (attached).
> 
> 
> The NCONC change is broken:
> 
> >(nconc (cons 'a 'b) (cons 'c 'd))
> 
> (A B C . D)   ;; <-- should not have the C
> 
> TAILP is also broken:
> 
> >(tailp nil '(a b . c))
> 
> T  ;; <-- NIL is not a tail of (a b . c)
> 

The fixes _I_ posted are _not_ broken:

> (nconc (cons 'a 'b) (cons 'c 'd))

(A C . D)

> (tailp nil '(a c . d))

NIL

Regards,
Peter