add-hook and lambda functions

add-hook and lambda functions

[Lennart Borgman (gmail)]

In hs-minor-mode a lambda function is added to the hook:

   (add-hook 'change-major-mode-hook
         (lambda () (hs-minor-mode -1))
         nil t)

Using a lambda function makes it a bit cumbersome to remove this hook if 
you want to. I would therefor prefer if named functions where used 
instead. Could this please be changed?

Re: add-hook and lambda functions

[Thien-Thi Nguyen]

() "Lennart Borgman (gmail)" <lennart.borgman@gmail.com>
() Fri, 30 Mar 2007 22:16:18 +0200

   In hs-minor-mode a lambda function is added to the hook:

     (add-hook 'change-major-mode-hook
           (lambda () (hs-minor-mode -1))
           nil t)

   Using a lambda function makes it a bit cumbersome to remove
   this hook if you want to.  I would therefor prefer if named
   functions where used instead.  Could this please be
   changed?

it's a pretty common idiom.  quick grep of "mode -1" shows
several dozen hits.  for example, in image-mode.el:

(add-hook 'change-major-mode-hook
          (lambda () (image-minor-mode -1))
          nil t)

if you want to codify the idiom and convert applicable calls
(including hideshow) to use the new code, that would be a good
thing to do (after the release, probably).

perhaps i am ignorant; does such an abstraction already exist?

thi

Re: add-hook and lambda functions

[Richard Stallman]

    In hs-minor-mode a lambda function is added to the hook:

       (add-hook 'change-major-mode-hook
	     (lambda () (hs-minor-mode -1))
	     nil t)

    Using a lambda function makes it a bit cumbersome to remove this hook if 
    you want to. I would therefor prefer if named functions where used 
    instead. Could this please be changed?

I agree.

There is no need to systematically change all such places,
at least not now; but if any of them actually gets in someone's way,
let's change it.  Apparently this one did.

Re: add-hook and lambda functions

[Chong Yidong]

Richard Stallman <rms@gnu.org> writes:

>     In hs-minor-mode a lambda function is added to the hook:
>
>        (add-hook 'change-major-mode-hook
> 	     (lambda () (hs-minor-mode -1))
> 	     nil t)
>
>     Using a lambda function makes it a bit cumbersome to remove this hook if 
>     you want to. I would therefor prefer if named functions where used 
>     instead. Could this please be changed?
>
> I agree.
>
> There is no need to systematically change all such places,
> at least not now; but if any of them actually gets in someone's way,
> let's change it.  Apparently this one did.

Done.

Re: add-hook and lambda functions

[Lennart Borgman (gmail)]

Chong Yidong wrote:
> Richard Stallman <rms@gnu.org> writes:
> 
>>     In hs-minor-mode a lambda function is added to the hook:
>>
>>        (add-hook 'change-major-mode-hook
>> 	     (lambda () (hs-minor-mode -1))
>> 	     nil t)
>>
>>     Using a lambda function makes it a bit cumbersome to remove this hook if 
>>     you want to. I would therefor prefer if named functions where used 
>>     instead. Could this please be changed?
>>
>> I agree.
>>
>> There is no need to systematically change all such places,
>> at least not now; but if any of them actually gets in someone's way,
>> let's change it.  Apparently this one did.
> 
> Done.

Thanks. It was very good to get this one done before the release.

Re: add-hook and lambda functions

[David Kastrup]

"Lennart Borgman (gmail)" <lennart.borgman@gmail.com> writes:

> Chong Yidong wrote:
>> Richard Stallman <rms@gnu.org> writes:
>>
>>>     In hs-minor-mode a lambda function is added to the hook:
>>>
>>>        (add-hook 'change-major-mode-hook
>>> 	     (lambda () (hs-minor-mode -1))
>>> 	     nil t)
>>>
>>>     Using a lambda function makes it a bit cumbersome to remove
>>> this hook if     you want to. I would therefor prefer if named
>>> functions where used     instead. Could this please be changed?
>>>
>>> I agree.
>>>
>>> There is no need to systematically change all such places,
>>> at least not now; but if any of them actually gets in someone's way,
>>> let's change it.  Apparently this one did.
>>
>> Done.
>
> Thanks. It was very good to get this one done before the release.

I find it surprising to have turn-off-hideshow without a corresponding
turn-on-hideshow.  Is the latter not expected to be used?  I don't
know hideshow enough to give an educated guess.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum

Re: add-hook and lambda functions

[Stefan Monnier]

> I find it surprising to have turn-off-hideshow without a corresponding
> turn-on-hideshow.  Is the latter not expected to be used?  I don't
> know hideshow enough to give an educated guess.

These are internal functions, not commands, so regularity is not
particularly important.


        Stefan