Ellipsis mode for zmacs?

[rsl@MAX-FLEISCHER.SF.Dialnet.ILA.COM (Richard Lamson)]

    Date: Wed, 26 Jun 1991 13:46-0400
    From: Barry Margolin <barmar@Think.COM>

	Date: Tue, 25 Jun 1991 19:05 EDT
	From: rsl@MAX-FLEISCHER.SF.Dialnet.ILA.COM (Richard Lamson)

	I assume so, because Concordia uses it.  I don't know anything about how
	you actually build buffers which can do this, though.

    I think this is the "disconnected sections" stuff that appeared in Zwei
    a few releases ago.

    Unfortunately, there don't appear to be any uses of this in the standard
    system, so there are no source examples to look at.  From what I can
    tell, the way you do this is to define a buffer flavor that implements the
    following messages:

    :UNLINKED-SECTIONS-P () - returns non-NIL
    :BUFFER-NEXT-UNLINKED-LINE (BUFFER LINE) - LINE will always be the last
    line of a section, and this should return the first line of the next
    section, or NIL if LINE was the last line of the last section.
    :BUFFER-PREVIOUS-UNLINKED-LINE (BUFFER LINE) - analogous for the other
    direction.

    You'd also probably need to implement a whopper for :SAVE to expand all
    the ellipses before writing the buffer out.

Yes.  You also need to replace the key line in ZWEI:FIND-FILE-NEW-BUFFER
which creates a buffer of the flavor ZWEI:FILE-BUFFER with one which
creates a buffer of your flavor, perhaps in response to the canonical
type in the pathname.