Dieter Maurer wrote:
> Jim Washington wrote at 2007-3-27 16:28 -0400:
>> ...
>> Yes, I think so, at least in the implementation/algorithm I am using. 
>> There may be other implementations that do not need this.  Note,
>> however, that the canonical list does not have to be complex objects. 
>> The canonical list is just a representation of the "unsorted" state.  It
>> can, for example, be a proxy list of iids, list indexes, or OOBTree
>> keys.  The algorithm does not care what it is reordering.
> If you need to keep the "canonical list" around, then sort them
> and then keep the sorted result around (i.e. cache the sorted list).
> This way, you could avoid the "factoradic index".
Yes, if there is only one ordering that will be used.  Factoradic
indices may be obtained and used for any arbitrary ordering of the
canonical list.  It may be useful, for example, to keep an index that
has books sorted by title, another one sorted by author and title, and
another one in publication date order.

- Jim Washington
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