- From: Dave Reynolds <der@hplb.hpl.hp.com>
- Date: Mon, 03 Sep 2007 13:33:15 +0100
- To: Jos de Bruijn <debruijn@inf.unibz.it>
- CC: RIF <public-rif-wg@w3.org>
Jos de Bruijn wrote: >>>>> There are some further differences between the specification >>>>> of the string datatype in XML schema 1.0 and XML schema 1.1; in the >>>>> former case, the datatype is based on the Char production in XML >>>>> 1.0; in >>>>> the latter case, the datatype is based on the Char production in XML >>>>> 1.1. >>>>> An important question is what to do with plain literals which contain >>>>> characters which are not in the lexical space of xsd:string. >>>> So there is a real difference there. XML 1.0 does not allow characters >>>> like BEL (those below #x20 other than #x9 #xA and #xD) XML 1.1 does >>>> allow those characters. >>> Are these characters (i.e. those below #x20 other than #x9 #xA and #xD) >>> actually Unicode characters? >> Yes, though they are control characters rather than displayable characters. >> >> Note that even though the XML1.1 spec allows them in the Char production >> it "discourages" them: >> >> [[[ >> Document authors are encouraged to avoid "compatibility characters", as >> defined in Unicode [Unicode]. The characters defined in the following >> ranges are also discouraged. They are either control characters or >> permanently undefined Unicode characters: >> >> [#x1-#x8], [#xB-#xC], [#xE-#x1F], ... >> ]]] > > So, every RDF plain literal without a language tag is an xsd:string in > XML Schema 1.1, but there are plain literals without language tags which > are not xsd:strings in XML Schema 1.0. > > So, if we go for XML Schema 1.0, then we have to tackle this issue in > RDF compatibility. Of course the only normatively defined format for RDF exchange (at present) is RDF/XML and people using XML 1.0 can't express the control characters anyway. Dave -- Hewlett-Packard Limited Registered Office: Cain Road, Bracknell, Berks RG12 1HN Registered No: 690597 England
Received on Monday, 3 September 2007 12:33:49 UTC