bug#21464: 25.0.50; [cc-langs] void-function cadar

[Alan Mackenzie]

Hello, Stefan.

In article <mailman.969.1442020629.19560.bug-gnu-emacs@gnu.org> you wrote:
>> "Eval error in the ?c-lang-defvar? or ?c-lang-setver? for ?comment-start? 
>> (source eval): (void-function cadar)"

I've gone and replaced cadar with cadr/car in the two places it appeared
in cc-langs.el.  They were the only occurrences of c[ad]\{3,\}r in CC
Mode.  There are quite a few compositions of caar, etc., with car and cdr,
and even compositions of car and cdr, presumably dating from a time before
caar etc. existed.

> Using cl-lib instead of cl would solve such issues easily since we could
> use cl-cadar and (require 'cl-lib) at run-time instead of only requiring
> cl at compile-time.

CC Mode in Emacs (as opposed to XEmacs) has been using cl-lib instead of
cl for some weeks, now.

> I know we've discussed it already, but I urge you (Alan) to take
> another look at the idea of unconditionally using cl-lib (and just
> bundling it with cc-mode).  I'd be happy to help you do that.

Bundling cl-lib with CC Mode doesn't feel like the Right Thing to do.  It
would be bound to clash with a cl-lib in Emacs (or a cl in XEmacs)
somehow.

> Then you'll be free to use CL functions (via the cl-*
> namespace) anywhere without having to worry about whether it's used at
> runtime or compile time.

> This is bound to happen sooner or later since cl.el is slated to move from
> lisp/emacs-lisp to lisp/obsolete and then to GNU ELPA.

> But even if cl.el were to stay in lisp/emacs-lisp, I think CC-mode
> maintenance would benefit from it.

Possibly.  But there doesn't seem to be an urgent need for it at the
moment.

I'm marking this bug as closed.

>         Stefan

-- 
Alan Mackenzie (Nuremberg, Germany).