- From: Frank Legler <legler@sigma.informatik.hu-berlin.de>
- Date: Mon, 17 Jan 2005 17:58:44 -0800
- To: "Michael Rys" <mrys@microsoft.com>
- CC: <legler@informatik.hu-berlin.de>, "Laurens Holst" <lholst@students.cs.uu.nl>, <legler@informatik.hu-berlin.de>, <public-qt-comments@w3.org>
According to Ashok's mail from 5 Nov 2004 (http://lists.w3.org/Archives/Public/public-qt-comments/2004Nov/0019. html) is it "possible to construct xs:QName and xs:NOTATION from string literals" If the casting table (http://w3.org/TR/xpath-functions/#casting-from-primitive-to-primitive) applies for both casts and constructors, then there is a contradiction in the F&O spec. Regards, Frank Michael Rys wrote: > The casting table applies to both forms: > > So if the casting tables says that you cannot cast from one type to > another, it applies to both cast as Type and Type(). > > Best regards > Michael > > >>-----Original Message----- >>From: public-qt-comments-request@w3.org [mailto:public-qt-comments- >>request@w3.org] On Behalf Of Frank Legler >>Sent: Monday, January 17, 2005 10:24 AM >>To: Laurens Holst >>Cc: legler@informatik.hu-berlin.de; public-qt-comments@w3.org >>Subject: Re: [F&O] Casting to xs:NOTATION, xs:QName not clarified >> >> >>At Saturday, 15 January 2005, Laurens Holst <lholst@students.cs.uu. >>nl> wrote: >> >> >>>Frank Legler wrote: >>> >>>>Hello Ashok, >>>> >>>>Does that mean that it is possible to construct xs:QName and xs:NOTATION >>>>from xs:string, >>>>but it is not possible to cast xs:QName and xs:NOTATION from a xs: >>>>string? >>> >>>From section 17.6 of XQuery 1.0 and XPath 2.0 Functions and Operators: >>> >>>"Casting from xs:string and xdt:untypedAtomic to xs:QName, xs: NOTATION, >>>or types derived from them is not possible because it requires knowledge >>>of the namespace context. Constructor functions are available to >>>construct values of these types provided that the lexical representation >>>is known statically." >>> >> >>I still do not understand why we differentiate between casting and >>construction here. >>Given the following examples >> (1) "a" cast as xs:QName (: invalid according to the spec :) >> and >> (2) xs:QName("a") (: valid according to the spec :) >> >>Don't both examples require knowledge of the namespace context? >>And why is a static evaluation possible for (2) but not for (1)? >> >>Regards, >>Frank >> =================================================================== Mail was send from https://www.informatik.hu-berlin.de/ EASY and FREE access to your email anywhere: http://Mailreader.com/ ===================================================================
Received on Tuesday, 18 January 2005 02:00:02 UTC