Re: Overriding inherited face attributes

[Stephen Berman <stephen.berman@gmx.net>]

On Wed, 28 Nov 2018 18:18:25 +0200 Eli Zaretskii <eliz@gnu.org> wrote:

>> From: Stephen Berman <stephen.berman@gmx.net>
>> Cc: help-gnu-emacs@gnu.org
>> Date: Wed, 28 Nov 2018 14:13:39 +0100
>> 
>> >> (insert (propertize "hello" 'face '(:inherit (:foreground "orange")
>> >> :foreground "red")))
>> >> 
>> >> makes the face display as red, and this seems to conflict with the above
>> >> documentation.
>> >
>> > It doesn't, because ':foreground "red"' is not the "underlying face".
>> 
>> That occurred to me, but then I have to conclude I really don't
>> understand the doc, according to my reading of which the `inherit'
>> property should have higher priority by virtue of being earlier in the
>> list.
>
> If someone has concrete proposals for how to make the documentation of
> these aspects better, I'm open to suggestions.

It would be helpful to know from precisely which part of the
documentation it follows that evaluating this:

(insert (propertize "hello" 'face '(:foreground "red" :inherit
(:foreground "orange"))))

displays "hello" in orange while evaluating this:

(insert (propertize "hello" 'face '(:inherit (:foreground "orange")
:foreground "red")))

displays "hello" in red.  I don't see how it follows from the passage in
the Lisp manual I cited ("Faces occurring earlier in the list have
higher priority") unless "occurring earlier in the list" and "higher
priority" have non-standard meanings, which should then also be defined
in the documentation.  And from what you wrote above, the higher
priority of the `inherit' property is irrelevant in these examples,
since as you said "':foreground "red"' is not the "underlying face".  So
can you point out the passage(s) in the manual from which the above
observed differences follow?  Maybe once I see that I'll be satisfied
with the existing documentation, or else could try to suggest
improvements.

Steve Berman