RE: CommonLisp namespace system (was Re: adding namespaces to emacs-lisp (better elisp?))

[Drew Adams <drew.adams@oracle.com>]

> > I read your proposal overview, Nic.  It's not clear to me just what
> > the differences would be from the Common Lisp package system.
> > Perhaps you could spell the differences out in more detail somewhere.
> >
> > But the closer we can get to the CL spec the better, IMO.  If we
> > could conform to it completely, that would be great.
> 
> I disagree. Emacs isn't CommonLisp, never has been CommonLisp and
> very likely, never will be CommonLisp.

Some of us nevertheless hope it will become closer in many respects.

> > Even keeping the same terminology, symbol names etc. as CL would
> > help.  It would help users who are coming from Common Lisp or who
> > happen to read Common Lisp doc.
> 
> But at the expense of muddying the waters for people who are not from
> that world.

"That world" is a longstanding one, with a rigorous, if informal, spec.

Emacs Lisp is younger (even if Emacs, in one form or another, is older
than Common Lisp itself, though not older than its ancestors).  And
Emacs Lisp has no spec - it is defined rigorously only by its (ever
moving) implementation.

And of course if Emacs adopts Common Lisp packages or similar then the
two worlds approach, and the waters become clearer with time and closeness.

> In Emacs world, we use "package" to mean something different from what
> CL "package" means.

That's a very recent introduction to the "Emacs world".  Hardly much of
a precedent.  "In [the] Emacs world" is a pretty bold way of describing
something we just introduced, as if it were essential to what Emacs Lisp
has always been.  It is a recent add-on - a welcome one, but hardly core.

And the question here is not about abandoning package.el etc.  It is
about the terminology: "package".  Who heard of Emacs "packages" a few
years ago?  Contrast that with who had heard of Common Lisp "packages".

> So right at the start that effort is doomed without
> a major change to Emacs 24.

Introducing proper packages (a la Common Lisp) would likely be a major
change to Emacs, yes.  And a welcome one, IMO.

> > Of course, adopting CL terminology in this regard should mean that
> > we would drop the terminology used so far for Emacs "packages".
> > An argument can be made that both uses of the word "package" are
> > somewhat unfortunate.
> 
> I am trying to make a namespace system that would be backwards
> compatible with Emacs and yet encourage future good behaviour.
> 
> CommonLisp terminology or compatibility is not a major aim of mine.

Too bad.  Emacs Lisp is already farther from Common Lisp than it should
be after 30-some years.