$Id: gl.html,v 1.16 2002/12/19 17:36:38 Vegai Exp $
| Tuomas Lukka
This is a short glossary of terminology related to GZigZag.
Only a short definition of each term is given, possibly with
a reference to more material on the subject.
Note that this document contains some formatting that is best rendered
using a true CSS1 standard-compliant browser such as Mozilla; however,
it should work reasonably well with any browser that can at least ignore
CSS that it doesn't understand. Unfortunately, Netscape Navigator 4.7,
for example, doesn't. Well, that's life...
A non-CSS version exists: you can try by compiling this
document from its WML version with some switches.. (if you came here
through the WWW, there should be an alternate link on the referring
page. However, I like
the pretty rendering by Mozilla so much that that's still the default.
- ZigZag structure / space
- A simple structure, based on cells and dimensions
which the user is able to easily shape into any desired
structure. All interrelated pieces of information can be
close to each other on some dimension.
- The smallest unit of information in ZigZag.
A cell can contain a text string or
a single span in a permascroll; the separation is
because a text string can be edited but a span can only
be lengthened or shortened: no characters can be
inserted. Cells are connected to each other along
- Connecting cells along dimensions is what ZigZag is
about. Locally, dimensions work just like on a spreadsheet:
each cell can be connected to one cell in the positive
direction and to one cell in the negative direction
along each dimension. However, there are no global constraints
between the dimensions.
- The negend of a rank, or, for
circular ranks, a specially designated cell.
If a rank of cells has one "special" cell, then
it is usually the headcell.
- Cells that are connected along a dimension are
called each other's neighbours. Often, the term
posward or negward is used with this term as in
"the negward neighbour on
- In the positive/negative direction along a rank.
- As far as you can go negwards or poswards.
Circular ranks have no ends.
- A rank on a dimension D is simply a set of cells that are
connected to each other on D. A given cell can only
be on one rank on a given dimension.
- A set of cells selected from the structure
by a set of rules, for visualization.
For example, the row and column raster select,
starting from the cursor,
a single rank in one dimension
an all ranks in another dimensions that
intersect that rank.
The raster for the vanishing view selects all
cells within a given radius of the cursor.
- relcell, or relation cell
- A cell which exists not for its content but for
expressing a relationship between other cells.
For example, the cell between a father and mother
in the family tree demo is a relcell.
- A rank which loops.
Ringranks still do have a specific headcell, specified
- These words simply correspond to ranks
being viewed horizontally/vertically.
They do not mean anything in the abstract structure,
but only in the visualizations.
- A way of placing the cells in a particular
raster on the screen.
- Ted Nelson's design built on top of ZigZag structure,
based on flobs.
- A multi-dimensional flying object. That is, an entity
representing something that may have any number of
flob coordinates. For example, an email's sender is one
flob coordinate, its subject another.
- A hypertext system, finished in 1988, which works by
stable fluid media content instead of URL-like pointers.
- fluid media
- Any media types that can be subdivided.
Text, audio, video, images.
- A storage philosophy for fluid media where
each smallest unit (e.g. character of text)
is assigned a permanent identifier when
it first enters the system. Of course,
references to the smallest units usually happen
through spans for efficiency.
- A (reference to a) contiguous section of the permascroll.
- A list of spans that describe a virtual stream of
fluid media. A "document" or one version of a document.
Modifying a document does not modify the permascroll, except
by appending new inserted characters. Instead, the spans
of the vstream are modified: split apart, new spans
- The inclusion of the same material in a permascroll in
two different documents. One of the fundamentals of the Xanadu88
model is that it is efficient to search for transclusions
of a given span.
- transpointing windows
- Windows on a computer screen that show the connections or
transclusions between each other.
- A copyright scheme where the copyright holder
grants the public a permission to refer to any
portion of a given document and publishes the document
in a permanent location.
This way, anyone can quote the document by referring
to it and the reader's browser will then go to the
originator's server for the original material so that
a micropayment can be made to the original author
of the material.