Re: reducing defface redundancy

[Richard Stallman <rms@gnu.org>]

    With the suggested algorithm, if he changes `:inherit mode-line',
    `:underline t', or adds a previously unused attribute, that change will
    apply to all environments.  However, if he changes `:background ...',
    the change will only apply to the relevant branch of the `conditional'
    in the defface spec.  So basically the rewritten face spec will look
    like the original face-spec except with the user's changes integrated.

    What do you think of this suggestion?

I think users will find this surprising and inconsistent.  In
addition, we want to have buffer-local face definitions, and that will
make this issue even more complex.

This is an instance of the general conflict between WYSIWYG editing
and conditional formatting commands.  That suggests we should
completely separate the WYSIWYG layer from the conditional command
later.  Here's a proposal.

You can customize a face for the current display, for the current
session, looking at a simple list of attributes, but you cannot save
this.  Or you can customize the conditional commands that define the
face, by looking at the whole structure of them.  That kind of
customization you can save if you wish.