cl-macs and (require 'cl)

cl-macs and (require 'cl)

[Lennart Borgman]

How is cl-macs.el supposed to be loaded? cl-macs.el has a (require
'cl) in it. Is that a bug or?

Re: cl-macs and (require 'cl)

[Davis Herring]

> How is cl-macs.el supposed to be loaded? cl-macs.el has a (require
> 'cl) in it. Is that a bug or?

If you do the recommended "(eval-when-compile (require 'cl))" in your code
and then use only macros from the CL package, the compiled file has
already had the macros expanded and contains no references to objects in
the CL package or to the 'cl symbol.  So it doesn't matter what's in
cl-macs.el.

Davis

-- 
This product is sold by volume, not by mass.  If it appears too dense or
too sparse, it is because mass-energy conversion has occurred during
shipping.

Re: cl-macs and (require 'cl)

[Lennart Borgman]

On Tue, Jun 30, 2009 at 11:07 PM, Davis Herring<herring@lanl.gov> wrote:
>> How is cl-macs.el supposed to be loaded? cl-macs.el has a (require
>> 'cl) in it. Is that a bug or?
>
> If you do the recommended "(eval-when-compile (require 'cl))" in your code
> and then use only macros from the CL package, the compiled file has
> already had the macros expanded and contains no references to objects in
> the CL package or to the 'cl symbol.  So it doesn't matter what's in
> cl-macs.el.
>
> Davis

The reason I am asking is that eieio.el in CEDET (which is going to be
included in Emacs soon) has this code

  (require 'cl)
  (load "cl-macs" nil t) ; No provide in this file.

Both lines seems wrong to me, but I do not know how it should look.

Re: cl-macs and (require 'cl)

[Stefan Monnier]

> How is cl-macs.el supposed to be loaded?

By (require 'cl).  Or more specifically

  (eval-when-compile (require 'cl))


-- Stefan

Re: cl-macs and (require 'cl)

[Stephen J. Turnbull]

Lennart Borgman writes:

 > The reason I am asking is that eieio.el

*shiver*

eieio has special needs.  You should ask the author(s) why they did it
this way, rather than using `(eval-when-compile (require 'cl))'.  If
they don't have any particular reason other than "well, it's been like
that since 1997", then you could try changing it to the recommended
form.

Re: cl-macs and (require 'cl)

[Lennart Borgman]

On Wed, Jul 1, 2009 at 8:09 AM, Stephen J. Turnbull<stephen@xemacs.org> wrote:
> Lennart Borgman writes:
>
>  > The reason I am asking is that eieio.el
>
> *shiver*
>
> eieio has special needs.  You should ask the author(s) why they did it
> this way, rather than using `(eval-when-compile (require 'cl))'.  If
> they don't have any particular reason other than "well, it's been like
> that since 1997", then you could try changing it to the recommended
> form.

Yes, that is why I asked here. Eric said he will change it.

But I do not know of any particular reason for including cl.el and
cl-macs.el like they did. Maybe you could explain?

Re: cl-macs and (require 'cl)

[Eric M. Ludlam]

On Wed, 2009-07-01 at 11:43 +0200, Lennart Borgman wrote:
> On Wed, Jul 1, 2009 at 8:09 AM, Stephen J. Turnbull<stephen@xemacs.org> wrote:
> > Lennart Borgman writes:
> >
> >  > The reason I am asking is that eieio.el
> >
> > *shiver*
> >
> > eieio has special needs.  You should ask the author(s) why they did it
> > this way, rather than using `(eval-when-compile (require 'cl))'.  If
> > they don't have any particular reason other than "well, it's been like
> > that since 1997", then you could try changing it to the recommended
> > form.
> 
> Yes, that is why I asked here. Eric said he will change it.
> 
> But I do not know of any particular reason for including cl.el and
> cl-macs.el like they did. Maybe you could explain?

Indeed, that is just the way it has been for a long time.  I did try
switching to the `eval-when-compile' part, but this doesn't work.  EIEIO
has functions which create types with deftype, and uses typep.  If I
wrap the require of cl as above, then sources creating classes can't
find the typep symbol.

It could be I am using deftype and typep in some inconsistent way.  If
someone is interested in pointing out the correct way to do these
things, I'd appreciate it.

You can look at EIEIO w/out getting the whole CEDET suite here:

http://cedet.cvs.sourceforge.net/viewvc/*checkout*/cedet/cedet/eieio/eieio.el?revision=1.185&pathrev=MAIN

Offending line #1 is at 569:  

There is some crufty old code here that can probably be done
differently.  I changed the eval thing in my copy to see if I could fix
it, but ran into a new problem:

The next offending line is at 1389

(defun eieio-perform-slot-validation (spec value)
  "Return non-nil if SPEC does not match VALUE."
  ;; typep is in cl-macs
  (or (eq spec t)			; t always passes
      (eq value eieio-unbound)		; unbound always passes
      (typep value spec)))

I'm not sure about this one.  While it is true that EIEIO can disable
slot validation, I get a lot of value from it while developing new code.

Eric