default base-uri?

[Per Bothner]

What is the "default" base-uri when base-uri has not been
explicitly specified.  The XQuery specification says "none",
but what does that mean in practice?

If my query contains:
   fn:doc("foo.xml")
and assume there is no "declare base-uri" declaration.
Section C.1 of the specifcation says that an implementation
is allowed to overwrite or augment the default, so the result
is implementation-defined.  But what *should* it be, assuming
the user have not explicitly specifier a base uri?

* An error?
* Resolved relative to the source code of the XQuery, assuming
that is meaningful - e.g. the directory containing the query file?
* Resolved relative to the "current directory", assuming that
is meaningful?  If so, current directory at compile-time or at
run-time, if there is a distinction?  If the latter, then the
base-uri is not static - though one could define kludges
like "file:." or "current-directory:foo.xml".

I have some ideas, but maybe people with wider experience have
expectations they could share.
-- 
	--Per Bothner
http://xquery.com/mailman/listinfo/talk   http://per.bothner.com/