In trying to work out if it should be >[prefix=]uri or >prefix[=uri]
I had a look at the XCQL XML Schema on the CQL web site.
I could not find support for the default value - I assume its been
proposed after the XML Schema for XCQL was written.
How would it be done? Just make that sub-element of the <prefix> element
ps: I noticed there was a <prefixes> element allowed inside each
search clause and boolean operator node. An alternative would have
been to have three choices in operandType - searchClause, triple,
or prefix. The prefix element would then have a single child
operand element. But the current scheme works fine (except for
not supporting the omitted bit). Just a trifle harder to implement.
(For >a((((b=c)))) you have to push down the prefixes wrapped node.
Wrapping with a prefix element is easier. Not a big deal though.)