Re: A proposal for removing obsolete packages

[Stefan Monnier]

> One way to make it unusual (and allow things like advice to be placed in
> obsolete and removed later) would be if elisp functionality such as
> defadvice had their APIs maintained but implemented on top of newer
> functionality. For example, a macro in nadvice.el could re-implement
> defadvice on top of the replacement functions.

FWIW: defadvice *is* implemented on top of nadvice already.
Emacs-23.4's advice.el is 170KB.
Emacs-24.5's advice.el is 139KB (+ 24KB of nadvice.el).

I originally intended to delay such "re-implementation" of advice.el to
some later time, but I quickly realized that it was not an option
because otherwise you can't mix defadvice and advice-add on the
same function.

The problem of a long transition (as is likely to occur for advice.el)
could be reduced in the following way:
- Rather than completely remove the obsolete package (after N years),
  move it to GNU ELPA.  So people can still get their old code working,
  tho it takes an extra step.
- Implement an nadvice.el forward compatibility package in GNU ELPA
  (probably implemented on top of defadvice), like I did for cl-lib and
  cl-generic, so external packages can start using nadvice.el without
  having to wait for Emacs-24.3 to be considered "too old to support".


        Stefan