Re: [Emacs-diffs] master 5811404: Replace eldoc-documentation-function with a hook

Re: [Emacs-diffs] master 5811404: Replace eldoc-documentation-function with a hook

[Stefan Monnier]

>     * lisp/emacs-lisp/eldoc.el (eldoc-documentation-functions): New hook.

I thought it was agreed that it would be a bad idea.


        Stefan

Re: [Emacs-diffs] master 5811404: Replace eldoc-documentation-function with a hook

[John Wiegley]

>>>>> Stefan Monnier <monnier@iro.umontreal.ca> writes:

> I thought it was agreed that it would be a bad idea.

I was asked in IRC about this patch, and I couldn't see anything objectionable
about it. However, clearly I was unaware of previous discussion on the matter.
Mark, could you please revert until we have more consensus that we want to do
this?  Thank you.

-- 
John Wiegley                  GPG fingerprint = 4710 CF98 AF9B 327B B80F
http://newartisans.com                          60E1 46C4 BD1A 7AC1 4BA2

Re: [Emacs-diffs] master 5811404: Replace eldoc-documentation-function with a hook

[Mark Oteiza]

On 07/07/16 at 12:31pm, John Wiegley wrote:
> >>>>> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>
> > I thought it was agreed that it would be a bad idea.
>
> I was asked in IRC about this patch, and I couldn't see anything objectionable
> about it. However, clearly I was unaware of previous discussion on the matter.
> Mark, could you please revert until we have more consensus that we want to do
> this?  Thank you.

Commit fd020a29[0] was implemented only to make it possible for the default
value to be used, something hooks already do.  See Bug#19338.

It is unclear what discussion you are talking about.  Perhaps it's
here[1], but if not, I hope you will read it before asking me to make
more commit noise.  One could refer to a number of sources for developer
opinion on using advice in core, but perhaps it is best to quote the
Elisp manual:

     […] advice should be reserved for the cases where you cannot modify
     a function’s behavior in any other way.  If it is possible to do
     the same thing via a hook, that is preferable (see Hooks).  […] In
     particular, Emacs’s own source files should not put advice on
     functions in Emacs.  (There are currently a few exceptions to this
     convention, but we aim to correct them.)

[0] http://git.savannah.gnu.org/cgit/emacs.git/commit/?id=fd020a29
[1] https://lists.gnu.org/archive/html/emacs-devel/2016-06/msg00138.html

Re: [Emacs-diffs] master 5811404: Replace eldoc-documentation-function with a hook

[Dmitry Gutov]

On 07/08/2016 02:59 AM, Mark Oteiza wrote:

> It is unclear what discussion you are talking about.  Perhaps it's
> here[1], but if not, I hope you will read it

Did you?

https://lists.gnu.org/archive/html/emacs-devel/2016-06/msg00331.html

> One could refer to a number of sources for developer
> opinion on using advice in core, but perhaps it is best to quote the
> Elisp manual:
>
>      […] advice should be reserved for the cases where you cannot modify
>      a function’s behavior in any other way.  If it is possible to do
>      the same thing via a hook, that is preferable (see Hooks).  […] In
>      particular, Emacs’s own source files should not put advice on
>      functions in Emacs.  (There are currently a few exceptions to this
>      convention, but we aim to correct them.)
>
> [0] http://git.savannah.gnu.org/cgit/emacs.git/commit/?id=fd020a29
> [1] https://lists.gnu.org/archive/html/emacs-devel/2016-06/msg00138.html

Re: [Emacs-diffs] master 5811404: Replace eldoc-documentation-function with a hook

[Stefan Monnier]

>      […] advice should be reserved for the cases where you cannot modify
>      a function’s behavior in any other way.  If it is possible to do
>      the same thing via a hook, that is preferable (see Hooks).  […] In
>      particular, Emacs’s own source files should not put advice on
>      functions in Emacs.  (There are currently a few exceptions to this
>      convention, but we aim to correct them.)

A *-function variable is not an advice, but a hook.

It's a different kind of hook than those manipulated by add-hook (which
have names ending in -hook or -functions), but it's still a hook and
those have been used for many years in various parts of Emacs.

It just so happens that the operations that can manipulate those hooks
conveniently (add-function/remove-function) are provided in the same
file as the new advice-add, but that's only because it was convenient
and natural to implement advice-add on top of those new operations.


        Stefan

Re: [Emacs-diffs] master 5811404: Replace eldoc-documentation-function with a hook

[Leo Liu]

On 2016-07-09 20:27 -0400, Stefan Monnier wrote:
> A *-function variable is not an advice, but a hook.
>
> It's a different kind of hook than those manipulated by add-hook (which
> have names ending in -hook or -functions), but it's still a hook and
> those have been used for many years in various parts of Emacs.
>
> It just so happens that the operations that can manipulate those hooks
> conveniently (add-function/remove-function) are provided in the same
> file as the new advice-add, but that's only because it was convenient
> and natural to implement advice-add on top of those new operations.

May we have this incompatible change reverted?

Thanks,
Leo

Re: [Emacs-diffs] master 5811404: Replace eldoc-documentation-function with a hook

[Dmitry Gutov]

On 07/14/2016 04:36 PM, Leo Liu wrote:

> May we have this incompatible change reverted?

Indeed. Mark, could you please revert it already?