Why doesn't XML have Bag?
Lars Marius Garshol
larsga at ifi.uio.no
Sat Mar 27 12:52:12 GMT 1999
* Lars Marius Garshol
| It is a limitation of DTDs and was introduced because without this
| operator element content models are easily mapped to finite state
| automatons, but the introduction of the '&' separator makes automaton
| generation much more difficult.
* Paul Janssens
| Please correct me if I am wrong here but isn't that trivial?
| (you may get a BIG automaton, but it's not difficult to generate)
This is correct. However, the number of states required for n elements
is n! with this approach (ie: worse than exponential), which means
that the automaton doesn't just get BIG, for reasonably sized content
models it can get ABSOLUTELY MIND-BOGGLINGLY AWFULLY STUNNINGLY
> (! 10)
> (! 30)
In other words, this approach doesn't work at all.
| and it's 'easily' visualised by the number of possible shortest
| paths between two opposing points on a hypercube.
I can think of easier ways of visualising it, though possibly not
'easier' ones. :)
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