bug#11606: 24.1; Get rid of buffer local hook variables in find-file.el

bug#11606: 24.1; Get rid of buffer local hook variables in find-file.el

[Leo]

ff-pre-find-hook
ff-pre-load-hook
ff-post-load-hook
ff-not-found-hook
ff-file-created-hook

bug#11606: 24.1; Get rid of buffer local hook variables in find-file.el

[Stefan Monnier]

> ff-pre-find-hook
> ff-pre-load-hook
> ff-post-load-hook
> ff-not-found-hook
> ff-file-created-hook

I like removing things, but could you expand on why you think we should
remove these?


        Stefan

bug#11606: 24.1; Get rid of buffer local hook variables in find-file.el

[Leo]

On 2012-06-03 01:57 +0800, Stefan Monnier wrote:
> I like removing things, but could you expand on why you think we should
> remove these?

Not removing the hooks themselves but the buffer-local bits, i.e.

=== modified file 'lisp/find-file.el'
--- lisp/find-file.el	2012-05-04 05:14:14 +0000
+++ lisp/find-file.el	2012-06-03 02:06:57 +0000
@@ -284,11 +284,6 @@
 ;; No user definable variables beyond this point!
 ;; ==============================================
 
-(make-variable-buffer-local 'ff-pre-find-hook)
-(make-variable-buffer-local 'ff-pre-load-hook)
-(make-variable-buffer-local 'ff-post-load-hook)
-(make-variable-buffer-local 'ff-not-found-hook)
-(make-variable-buffer-local 'ff-file-created-hook)
 (make-variable-buffer-local 'ff-case-fold-search)
 (make-variable-buffer-local 'ff-always-in-other-window)
 (make-variable-buffer-local 'ff-ignore-include)

bug#11606: 24.1; Get rid of buffer local hook variables in find-file.el

[Stefan Monnier]

>> I like removing things, but could you expand on why you think we should
>> remove these?

> Not removing the hooks themselves but the buffer-local bits, i.e.

I also like removing those, but I still don't know why you think these
can be removed safely.


        Stefan

bug#11606: 24.1; Get rid of buffer local hook variables in find-file.el

[Leo]

On 2012-06-03 11:18 +0800, Stefan Monnier wrote:
> I also like removing those, but I still don't know why you think these
> can be removed safely.

I was thinking that add-hook supports adding local hooks which might be
better than making those hooks buffer-local. What are your concerns
about their safety?

Leo

bug#11606: 24.1; Get rid of buffer local hook variables in find-file.el

[Stefan Monnier]

>> I also like removing those, but I still don't know why you think these
>> can be removed safely.
> I was thinking that add-hook supports adding local hooks which might be
> better than making those hooks buffer-local.

That's generally true, but (add-hook 'foo 'bar) operates on the local
part if the var is `make-variable-buffer-local', so the removal you
suggest would break code that relies on this detail.

> What are your concerns about their safety?

My concern is that I know nothing about these variables, so I have no
way to judge whether removing those things is safe.


        Stefan

bug#11606: 24.1; Get rid of buffer local hook variables in find-file.el

[Juanma Barranquero]

On Sun, Jun 3, 2012 at 6:05 AM, Leo <sdl.web@gmail.com> wrote:

> I was thinking that add-hook supports adding local hooks which might be
> better than making those hooks buffer-local.

Most hooks and hook-like variables can be useful as either global or
buffer-local, and for these (add-hook X Y Z t) or (set
(make-local-variable X) Y) is the way to go.

But there are some hooks that make no sense as global variables, or
are never used that way. For these, being automatically buffer-local
is, in fact, less error prone.

A notable example is revert-buffer-function, which strangely we have
not made automatically-buffer local even when the 31 packages in
lisp/** that assign it do convert it to buffer-local first...

    Juanma