Rick Jelliffe wrote:
> My impression is that as soon as your schema language supports IDREF it
> is stuffed,
> from an NP POV: Schematron, XSD, RELAX NG, DTDs, the lot!
Why do you say that? Checking DTD-style IDREFs naively seems to be a
linear problem: just read the document twice, once to find the IDREFs
and once to find out whether anything matches them. Store the IDs and
IDREFs in a couple of stacks as you go and you could do it in a single
pass. Keep a counter for each IDREF to find out if it's matched more
than once.
The process would seem to be linear in the size of the document; not at
all NP-complete. What am I missing?
--
Elliotte Rusty Harold
XML in a Nutshell 3rd Edition Just Published!
http://www.cafeconleche.org/books/xian3/
http://www.amazon.com/exec/obidos/ISBN=0596007647/cafeaulaitA/ref=nosim
