Re: unload-feature questions and thoughts

["Juanma Barranquero" <lekktu@gmail.com>]

On 10/16/07, Richard Stallman <rms@gnu.org> wrote:

>     That's the idea, though for finer-grained control
>     FEATURE-unload-function can always modify `unload-hook-features-list'
>     before returning the "continue the standard processing" flag back to
>     `unload-feature'.
>
> How would that be useful?  What problem could it solve?

Well, that's how `unload-hook-features-list' is used right now,
according to docstrings.

From `unload-hook-features-list':

  This is meant to be used by FEATURE-unload-hook hooks, see the
  documentation of `unload-feature' for details.

From `unload-feature':

  Such a hook should undo all the relevant global state changes that may
  have been made by loading the package or executing functions in it.
  It has access to the package's feature list (before anything is unbound)
  in the variable `unload-hook-features-list' and could remove features
  from it in the event that the package has done something strange,
  such as redefining an Emacs function.


             Juanma