Re: add-list local value

[Stefan Monnier <monnier@iro.umontreal.ca>]

>>> Wouldn't it be practical to allow add-list to add to the buffer local value,
>>> like add-hook allows? At least I need it ...
>> 
>> It makes sense for add-hook because buffer-local values of hook include
>> a special entry t which means "run the global value of this hook".
>> 
>> For lists, it doesn't make much sense I believe.  Either the list is
>> global or it's local.  If it's local, just make it local with
>> make-local-variable.

> And if I have a local value and want to add to the global value with
> add-to-list?

A good reason why add-to-list is a bad function.

You can use

  (require 'cl)

  (pushnew <val> (default-value '<sym>))

or

  (setq-default <sym> (cons <var> (default-value '<sym>)))

or

  (unless (member <val> (default-value '<sym>))
    (setq-default <sym> (cons <var> (default-value '<sym>))))


-- Stefan