- From: Michael Kay <mhk@mhk.me.uk>
- Date: Wed, 3 Mar 2004 08:56:03 -0000
- To: "'Per Bothner'" <per@bothner.com>
- Cc: <public-qt-comments@w3.org>
OK, sorry: I phrased it wrong. In XSLT, if module A explicitly includes module B, then B implicitly includes A, in the sense that everything in A becomes visible in B. Although the references between modules can't be cyclic, the references between templates and functions can. The essence of the point I was trying to make is that there's no restriction on mutual recursion between templates/functions in different modules. Michael Kay # -----Original Message----- # From: Per Bothner [mailto:per@bothner.com] # Sent: 02 March 2004 19:49 # To: Michael Kay # Cc: public-qt-comments@w3.org # Subject: 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 Wednesday, 3 March 2004 03:56:58 UTC