Re: [Emacs-diffs] master e4de91d: Introduce new macros to cover Emacs's new names in cl-lib.el.

[Alan Mackenzie]

Hello, Stefan.

On Thu, Aug 13, 2015 at 12:02:20PM -0400, Stefan Monnier wrote:
> > The (eval-when-compile (require 'cl)) was inadequate, because
> > cl.el (now cl-lib.el) is now required at run-time, too.  Without the
> > change, the error "cl-mapcan not known" gets thrown when attempting to
> > visit the first file.c in an Emacs session.

> Oh, right, sorry, so the question becomes: what is the difference
> between `require' and `cc-external-require' here?

Not a great deal, to be honest.  The main difference is that symbols
whose function cell has been given a placeholder value to inhibit
compiler warnings have these function cells restored to their correct
values in `cc-external-require' around the actual `require'.

An example of an XEmacs function which gets this treatment is
`buffer-syntactic-context'.  An example of an Emacs function is
`string-to-syntax'.

>         Stefan

-- 
Alan Mackenzie (Nuremberg, Germany).