xml-dev - Re: Why doesn't XML have Bag?

["Frank Boumphrey" <bckman@ix.netcom.com>]

In SGML you can put
(a&b&c) whicch means that eachelement must appear only once but in any
order.

The best you can do in XML (without getting rediculosly complicatedis

(a|b|c)* which means that they can appear in any order, but there can be any
number of them

My understanding was that it was ommited because of the requirement

"XML software shall be easy to write"

It takes only a few lines of C code to validate the second requirement but a
LOT more to validate the first.

Frank
----- Original Message -----
From: Roger L. Costello <costello@mitre.org>
To: <xml-dev@ic.ac.uk>
Cc: <alk@mitre.org>; Roger Costello <costello@mitre.org>
Sent: Friday, March 26, 1999 6:59 AM
Subject: Why doesn't XML have Bag?


>Why doesn't XML support the notion of an unordered list of elements,
>i.e., a Bag?  Perhaps this is a limitation of DTD, not XML?  That is,
>DTDs do not support Bags, but XML has no such inherent limitation?  Does
>DCD support Bags?  /Roger
>
>
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