Re: Module unloading

[Neil Jerram]

Zeeshan Ali wrote:
> > There's no way of completely removing (=> undefining) the definitions
> > that a module added.
>
>       Hmm... But the GC would take care of that, wouldn't it? If it
> doesn'nt then the plugins must do that themselves in their
> 'xchat-plugin-deinit' procedure, which they must define and export.

It should do if you really can remove all the references to the module, 
but I'm not sure how easy that is; I think modules live (through 
membership of a global list?) even if no one is using them.

> > I think it might be possible (in an undocumented
> > and unsupported way) to "unuse" a module, though, i.e. to remove a
> > plugin module from the module-uses list of your main module.  Is that
> > any use to you?
>
>     I think that is exactly what i need. Maybe there is no way defined
> to do this as the GC also takes care of 'unused' modules as they are
> also normal guile objects? Thanks for your help.

Well here's what I had in mind:

(use-modules (ossau example-fns))   ; this module exports `fact1'

(define (unuse-named-module name)
  (let ((intf (resolve-interface name)))
    (set-module-uses! (current-module)
                      (delq intf (module-uses (current-module))))))

fact1 => #<procedure fact1 (n)>

(unuse-named-module '(ossau example-fns))

fact1 => ERROR: Unbound variable: fact1

It seems to survive 5 minutes of testing by me, but there could well be 
problems lurking, so please test carefully in your context.

        Neil