RE: question regarding element types in function definitions/XQue ry

We have recently established that the language spec and the formal semantics
give different answers to these questions, and there is a great debate going
on as to what the correct answer should be. Watch this space...

Michael Kay

> -----Original Message-----
> From: Todd A. Mancini [mailto:todd.mancini@daxat.com] 
> Sent: 21 February 2003 16:01
> To: public-qt-comments@w3.org
> Subject: question regarding element types in function 
> definitions/XQuery
> 
> 
> 
> I know this has been answered in one way or another over the 
> past year or so, but I'm still having trouble understanding 
> the specifications as the language and semantic specs. don't 
> seem to exactly agree, and the publicly available issue 
> resolution is somewhat unreadable.
> 
> If I define a function as follows:
> 
> define function foo($i as element my:elementdef) { 1 }
> 
> does this raise a static type error if I have not imported a 
> schema defining element my:elementdef ?
> 
> However, if I define a function as follows:
> 
> define function foo($i as element my:elementdef of type 
> xs:integer) { 1 }
> 
> does this raise a static type error if I have not imported a 
> schema defining element my:elementdef?  Conversely, what if I 
> have defined an element my:elementdef?  Provided xs:integer 
> is a subtype of the type of the globally defined 
> my:elementdef, is this acceptable?  Or, does this signature 
> imply that the argument need only have the element name 
> my:elementdef, with a type xs:integer, regardless of the 
> existence of my:elementdef as a global element definition?
> 
> 	Thanks,
> 	-Todd
> 
> PS: Another difference between the language and semantic 
> specifications relates to untyped function arguments and 
> function return values.  The language spec has them as 
> xs:anyType whereas the semantic spec has them as item*.  
> Although the difference is subtle, I believe that item* 
> matches more values than xs:anyType.  (e.g.  (element foo, attribute
> bar) matches item* but not xs:anyType, whose value space has 
> all attributes preceding all elements, assuming I'm correctly 
> interpreting 3.2.4 in semantic spec.)
> 
>

Received on Saturday, 22 February 2003 07:31:48 UTC