Re: defer cyclic module import until XQuery 1.0

Michael Kay wrote:
> It's worth pointing out that XSLT has always allowed cyclic includes and
> imports, with no restrictions on forwards references or cross-module mutual
> recursion.

There is this "Michael Kay" guy who seems to disagree with you:
"XSLT Programmer's Reference", 1st edition, page 220:
"A stylesheet must not directly or indirectly include itself."

Some guy with the same name is listed as editor of "XSL Transformations
(XSLT) Version 2.0 - W3C Working Draft 12 November 2003" which says:
"[ERR XT0180] It is a static error if a stylesheet module directly or 
indirectly includes itself." and
"[ERR XT0210] It is a static error if a stylesheet module directly or 
indirectly imports itself."

Or are we talking about different things?

> So it can't be that difficult. Of course, no-one ever tried to
> write the formal semantics for it.

It's not just formal semantics, but *static* semantics.  XQuery supports
lexical scoping and static type-checking; XSLT has neither.  I'm sure
one *can* do lexical scoping and static type-checking with mutually
dependent modules (C does it, sort-of), but I'm also sure that the
drafts I've seen don't come close to a consistent or workable
specification, formal or informal.
-- 
	--Per Bothner
per@bothner.com   http://per.bothner.com/

Received on Tuesday, 2 March 2004 14:49:19 UTC