Re: convert from setq to customization

[Per Abrahamsen <abraham@dina.kvl.dk>]

Ted Zlatanov <tzz@lifelogs.com> writes:

> On Thu, 06 Mar 2003, abraham@dina.kvl.dk wrote:
>> User options, i.e. anything declared by defcustom or defface, should
>> only be modified the user, either by setq's in .emacs or
>> interactivly through customize.
>> 
>> If it is done by other Lisp packages, they risk conflicting with the
>> users choices.
>
> What if package A has variable A1, which needs to be overridden by
> package B because of variable B1?

Split the variable in two, A1-user and A1-default the first being
defcustom (for the user) and the second defvar (for other packages),
with the first taking precedence over the second if changed .

> For example, spam.el requires nnimap-split-download-body in nnimap.el
> to be set if a statistical filter is selected, so the whole message
> body is downloaded.

If ann option explicitly set by the user prevent another package from
running, that package should give an error, not overwrite the EXPLICIT
user choice.

Defaults is another case, covered by my suggestion above.