Re: face-remapping patch

[David Kastrup <dak@gnu.org>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> Miles, could you clarify why you are proposing a remapping list rather than
>> "buffer-local faces"?
>
> I think adding "buffer-local faces" directly is no better.  The good
> thing about Miles's patch is that it leverages buffer-local variables to
> modify faces buffer-locally.  As a result, his patch is pretty small.
>
> To improve on this, I think we'd have to move to something more like
> XEmacs's specifiers.  But I haven't even seen any proposal for such
> a thing yet.

Proposal: allow a third argument for make-local-variable.

(make-local-variable VARIABLE &optional locus)

Make VARIABLE have a separate value in the given locus (defaulting to
the current buffer).

A locus can be a buffer, a frame, a terminal, a window.  When there is
more than one locus for which a variable may be local, the value is used
from the first locus in the list window - buffer - frame - terminal.

(local-variable-p VARIABLE &optional LOCUS)

Non-nil if VARIABLE has a local binding in locus LOCUS (see make-variable).
BUFFER defaults to the current buffer.

variable-binding-locus is a built-in function in `C source code'.

(variable-binding-locus VARIABLE)

Return a value indicating where VARIABLE's current binding comes from.
If the current binding is buffer-local, the value is the current buffer.
If the current binding is frame-local, the value is the selected frame.
If the current binding is global (the default), the value is nil.



Bing.  A simple API, easy to understand, easy to use.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum