Re: proposal for ordered collections

I agree with Jim's proposal for ordered collections but would like
to suggest a couple of modifications.

1. The addition to the Insert-Position header of a third type of argument,
   an index which is a token that specifies the place in the
   collection where the document should be inserted. This index should
   be opaque to the protocol but will have meaning to both the client and
   the serverd. An example being the version number of a revision being
   added to an archive. i.e 1.5.
   If the server refuses to insert the member at the specified position
   it may choose to insert it at a different location.

2. The server should return a header after a member has been inserted into
   a collection that indicates it's position (the index mentioned above).

3. It should not be mandated that the server always insert members at the
   end of a collection if no position is specified, but instead it is left
   to the server to insert the member where it wants and return the position
   using the header mentioned in 2. This is because the ordering of the collection
   may be based on some aspect of the member being inserted. Such as alphebetically
   by file name.

On the matter of multiple orderings, I feel that while there are no doubt
applications where this would be needed, my guess is that having one default
order to collections will cover the vast majority of the cases. Multiple orderings
may cause more complexity than they are worth.

Someone suggested that an unordered collection is really just a special case of
an ordered collection where the server picks the order. I agree with this but it
must be pointed out that the server would either have to refuse any attempts to 
insert members in a specific place in an "unordered" collection, or it would always
have to respond by saying "this is where i put the member instead".

Steve
-- 
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Received on Friday, 19 December 1997 14:41:24 UTC