Re: About `unload-feature'

[Barry Margolin]

In article <mailman.16498.1357082632.855.help-gnu-emacs@gnu.org>,
 Dmitry Gutov <dgutov@yandex.ru> wrote:

> Xue Fuqiao <xfq.free@gmail.com> writes:
> 
> > (info "(elisp) Unloading") says:
> >
> > Before restoring the previous definitions, `unload-feature' runs 
> > `remove-hook'
> > to remove functions in the library from certain hooks. These hooks include
> > variables whose names end in `-hook' (or the deprecated suffix `-hooks'), 
> > plus
> > those listed in `unload-feature-special-hooks', as well as 
> > `auto-mode-alist'.
> > This is to prevent Emacs from ceasing to function because important hooks 
> > refer
> > to functions that are no longer defined.
> >
> > What does `ceasing to function' mean?  Can anybody help?  Thanks.
> 
> Looks like a hyperbole.
> 
> It would still function, but signal [lots of] "function is undefined" errors.

There are some hooks that are run very frequently -- if these signalled 
an error every time, Emacs would be effectively unusable.

-- 
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
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