prevent hook vanishing

prevent hook vanishing

[akrl]

Hi all,
How do I prevent emacs from removing a hook I've installed using
something like:
(add-hook 'after-change-functions 'render-buf nil t) in case of an error
occur executing it?

I would also be fine in being able to reinstall it somehow afterward.

Bests
   akrl

-- 
akrl@sdf.org
SDF Public Access UNIX System - https://sdf.org

Re: prevent hook vanishing

[John Mastro]

akrl <akrl@sdf.org> wrote:
> How do I prevent emacs from removing a hook I've installed using
> something like: (add-hook 'after-change-functions 'render-buf nil t)
> in case of an error occur executing it?

> I would also be fine in being able to reinstall it somehow afterward.

Why not use `condition-case' in your hook function to catch the error
and respond appropriately? (There are also `with-demoted-errors' and
`ignore-errors', if there's nothing that needs to be except to suppress
the error)

         John

Re: prevent hook vanishing

[akrl]

John Mastro <john.b.mastro@gmail.com> writes:

> Why not use `condition-case' in your hook function to catch the error
> and respond appropriately? (There are also `with-demoted-errors' and
> `ignore-errors', if there's nothing that needs to be except to suppress
> the error)
>
>          John

Doesn't quite work. I wrap the hooked code around using ignore-errors,
then for instance if I get the following error (from *Messages*):
"Symbol's value as variable is void"
the hook is wiped out.

Bests
  akrl

-- 
akrl@sdf.org
SDF Public Access UNIX System - https://sdf.org

Re: prevent hook vanishing

[John Mastro]

akrl <akrl@sdf.org> wrote:
> > Why not use `condition-case' in your hook function to catch the error
> > and respond appropriately? (There are also `with-demoted-errors' and
> > `ignore-errors', if there's nothing that needs to be except to suppress
> > the error)

> Doesn't quite work. I wrap the hooked code around using ignore-errors,
> then for instance if I get the following error (from *Messages*):
> "Symbol's value as variable is void"
> the hook is wiped out.

Hm, then you may have another problem. The following simple example
works for me:

     (defun boom-after-change (&rest _)
       (ignore-errors (error (message "Boom!"))))

     (add-hook 'after-change-functions #'boom-after-change nil t)

Hope that helps

         John

Re: prevent hook vanishing

[akrl]

John Mastro <john.b.mastro@gmail.com> writes:

> Hm, then you may have another problem. The following simple example
> works for me:
>
>      (defun boom-after-change (&rest _)
>        (ignore-errors (error (message "Boom!"))))
>
>      (add-hook 'after-change-functions #'boom-after-change nil t)
>
> Hope that helps
>
>          John

Thanks John,
that worked perfectly for me now, seems I was wrapping at the wrong level.

Bests!
  akrl

-- 
akrl@sdf.org
SDF Public Access UNIX System - https://sdf.org