Definition: tumbler	last revised by 127.0.0.1 on Aug 17, 2005 4:27 am

An early type of coordinate space, used primarily in Udanax-green. It appears in Udanax-gold as well, as part of the taxonomy of possible coordinate spaces.

A tumbler is like the number assigned in the dewey decimal system or in SCCS style revision numbers. An example tumbler would be: 1.1.4.5.6.0.3.4.67.0.888.33.22.1.0.2234

A tumbler is an example of a transfinite number.

The advantages of this as a numbering system for Xanadu addressing are:

1. There is always a tumbler between two different tumblers, so insertions never require renumbering.

2. A set of tumblers can be ordered.

3. The tumblers can be arranged to form a hierarchy, making it easy to specify all tumblers that start with a shorter tumbler. This is used in the Xanadu green system for queries like "all documents of this user". This is also useful for delegating assignment authority, like in the DNS.

4. Arithmetic can be done with tumblers. Specifically addition and subtraction, making it possible to specify ranges of tumblers.

In Xanadu green, the tumblers are in the form (with all components specified): 1.<node>.0.<user>.0.<document>.0.<content> where each <piece> is a tumbler fragment.

So the tumbler specifing the 3rd text byte of the document 10.3.5.6 for user 77.2334556.78.2 on the node 99.432 would look like 1.99.432.0.77.2334556.78.2.0.10.3.4.6.0.1.3 . Shorter forms are allowed as are tumbler differences, so asking for all data starting from 1. with an extent of 1 will give you everything in the system. Asking for all data starting from 1.99.432.0.77.2334556.78.2 with an extent of 0.0.0.0.0.0.0.1 will give you all of the documents belonging to user 1.99.432.0.77.2334556.78.2.

--JohnDougan?