Re: kill ring menu

[Miles Bader]

Colin Walters <address@hidden> writes:
> > My impression was that there was a hierarchy -- `real' properties would
> > always override `aliases', and `aliases' would be applied in strictly
> > the same order as they occurred in the appropriate alist entry.
> 
> Can you see a situation where this would make using the feature
> significantly easier?

Not offhand; situations that come to mind are probably adequately
covered by either the `overlay > text-property' prioritization, or by
explicit overlay priorities.

I think that, as you said, most people will think of them as basically
`just like face properties', and use the existing methods to handle
potential conflict.

However, when possible I prefer predictable behavior over unpredictable
behavior.  It may be that in this case, the benefit in simplicity of
implementation outweighs the lack of predictability; I don't know
(though I will note that it's usually easier to make fewer guarantees at
first, and add them later if necessary).

> As is, I don't imagine many modes will use this feature, except
> indirectly by using `font-lock-face', and having font-lock toggle the
> alias.

I think there are many possible uses for this feature.

Here's something I wrote in an earlier message:

   That's one cool think about this approach, BTW, is that then you can
   maintain multiple `views' of the faces (and invisible regions, etc.) in
   a buffer and easily switch between them.  Not that I'm sure of a good
   use for such a capability, mind you ... well, it would make implementing
   blinking text easy.  :-)   Hmm, maybe it could be used for outline mode
   or something...

   Oh, and the multiple views wouldn't even have to be `switched between',
   then could be each turned on or off individually (by adding or removing
   the associated `face alternative' property to/from the alis entry), and
   they would be applied to the text in the same order as the alist (e.g.,
   earlier alternatives take precedence).

   So in effect it allows you to have independent face layers than can each
   be turned on or off easily.

[note that I assumed the ordering of property alternatives]

-Miles
-- 
`...the Soviet Union was sliding in to an economic collapse so comprehensive
 that in the end its factories produced not goods but bads: finished products
 less valuable than the raw materials they were made from.'  [The Economist]