Why doesn't XML have Bag?

Leigh Dodds ldodds at ingenta.com
Fri Mar 26 12:40:50 GMT 1999

> 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

An XML newbie writes....

Isn't this an unordered list of elements?

<!ELEMENT BAG	(A?,B?,C?,D?)+>

Which appears to have order, but as elements are optional 
and the group is repeatable the ordering isn't enforced. Although 
the bag can't be empty. So, you could have...

<!ELEMENT BAG	(A?,B?,C?,D?)*>

Which allows an empty BAG

Or am I completely wrong?



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