Re: Feature request: permanent-local values in hooks buffer local values

["Lennart Borgman (gmail)" <lennart.borgman@gmail.com>]

Lennart Borgman (gmail) wrote:
> Richard Stallman wrote:
>>     Then in `flymake-mode' a call to the functions
>>     `flymake-add-survivor' and `flymake-remove-survivor \(which was 
>> defined     by the macro called above) must be done.
>>
>> This seems like a very cumbersome interface.  I think it is very
>> unclean to dynamically change `permanent-local' properties.  That's
>> the sort of thing that we are sure to regret.
>>
>> We should use my mechanism instead.  It is simple and clean.
> 
> That is very fine with me.
> 
> I suggest then adding something like this to the end of add-hook:
> 
>     (when (and local
>                (get function 'permanent-local-in-hooks))
>       (put hook 'permanent-local-hook t)
> 
> Then in kill-local-variables check for the property 
> 'permanent-local-hook and handle the hook accordingly.
> 
> I can see no reasonable way to remove the property 'permanent-local-hook 
> from the hook variable. (The problem is that properties do not have 
> buffer local values. It could be simulated by having a buffer local 
> variable carrying the propery, but I see no reason to make it that 
> complicated.)

     (when (and local
                (and (symbolp function))
                (get function 'permanent-local-in-hooks))
       (put hook 'permanent-local-hook t)