open source, xanadu, persistence and other things (was: Udanax ?)

Laurent Martelli
29 Oct 1999 03:23:12 +0200

>>>>> "Jecel" == Jecel Assumpcao <> writes:

  >> > I had tested ZigZag a few weeks ago (it is not in a state that
  >> > I would pay $25 for it) and found the ideas interesting. I
  >> think > objects would handle what his cells do pretty well,
  >> though.
  >> Cells and objects are completely irrelevant (a cell IS an
  >> object).  Links are everything.  I'm not impressed with ZigZag,
  >> but you have to understand it in order to understand Xanadu.

  Jecel> David Ungar says the same thing about Self: that objects and
  Jecel> object-oriented programming aren't good, but a bunch of
  Jecel> linked objects and how they connect together - that is
  Jecel> everything.

  Jecel> I like to "think different" :-), so I liked to play with
  Jecel> ZigZag.  But when you think about it, there is no great
  Jecel> different between saying that C3 follows C2 in the "weight"
  Jecel> dimension in ZigZag, or having the relation weight(C2,C3) in
  Jecel> Prolog, or have the "weightNext" slot of the C2 object refer
  Jecel> to the C3 object...

Considering available OOL, this makes a very big difference, since the
slot belongs to C2. Adding another relation requires that you modifiy
C2, and that's not possible at run-time for most OOL. Creating a new
relation that refers to C2 does not have this problem.

Laurent Martelli