Re: Overlays as an AA-tree

[Stefan Monnier]

> Beware: we cannot use their code due to copyright issues, so it's
> probably not wise to look at the code there.

IIRC the majority of XEmacs's code can be integrated into Emacs
with no issue w.r.t copyright.  But yes, it requires scrutiny.

> I actually don't understand the request: what is meant by "design"
> here?  If there are some features we lack in the overlays, then
> corresponding feature requests (better yet, patches) would be
> appreciated.  After reading extents.texi, I don't see any significant
> features missing, except the ability to copy overlays with the text
> (which AFAIR XEmacs implements somewhat inconsistently, as only some
> of the primitives that process text support that).  Is there something
> else?

I think the reference wasn't to the exposed API but to the underlying
implementation technique, but XEmacs uses doubly-linked lists to store
their extents, so it's no better than what we have.


        Stefan