[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RE: Brain Teaser: Element Author is of type xsd:string, what's
Michael Kay writes: > There's a W3C note on handling XML 1.1 with XML Schema: > > http://www.w3.org/TR/xml11schema10/ > > and it recommends (see the last line of the note) that with that > combination, the definitions of the built-in types should be "stretched" to > accommodate the characters allowed in XML 1.1. With that strategy, there > will never be an invalid instance of xs:string. Indeed. That's about the best we could do without appearing to make a retoactive incompatible change to Schema 1.0. With Schema 1.1, such incompatibilities are less of an issue. Note that the latest public working draft of Schema 1.1 says [1]: "[XML Schema: Datatypes] defines some datatypes which depend on definitions in [XML 1.1] and [XML-Namespaces 1.1]; those definitions, and therefore the datatypes based on them, vary between version 1.0 ([XML 1.0], [XML-Namespaces 1.0]) and version 1.1 ([XML 1.1], [XML-Namespaces 1.1]) of those specifications. In any given schema-validity-·assessment· episode, the choice of the 1.0 or the 1.1 definition of those datatypes is implementation-defined." The working draft for Schema 1.1 Datatypes provides more details [2]: "This specification defines some datatypes which depend on definitions in [XML] and [Namespaces in XML]; those definitions, and therefore the datatypes based on them, vary between version 1.0 ([XML 1.0], [Namespaces in XML 1.0]) and version 1.1 ([XML], [Namespaces in XML]) of those specifications. In any given use of this specification, the choice of the 1.0 or the 1.1 definition of those datatypes is implementation-defined. "Conforming implementations of this specification may provide either the 1.1-based datatypes or the 1.0-based datatypes, or both. If both are supported, the choice of which datatypes to use in a particular assessment episode should be under user control. Note: When this specification is used to check the datatype validity of XML input, implementations may provide the heuristic of using the 1.1 datatypes if the input is labeled as XML 1.1, and using the 1.0 datatypes if the input is labeled 1.0, but this heuristic should be subject to override by users, to support cases where users wish to accept XML 1.1 input but validate it using the 1.0 datatypes, or accept XML 1.0 input and validate it using the 1.1 datatypes. " Regarding "string" in particular, the Datatypes draft says [3]: "It is implementation-defined whether an implementation of this specification supports the Char production from [XML], or that from [XML 1.0], or both. See Dependencies on Other Specifications (§1.3)." So I think we've been quite careful with the details there, and Schema 1.1 can indeed be used to validate as strings the characters that Roger mentions. Note that there are some characters that are not allowed in either XML 1.0 or XML 1.1 infosets, and thus are disallowed even in Schema 1.1 strings. I believe I'm correct that NUL (0x0) is one of these. Noah [1] http://www.w3.org/TR/xmlschema11-1/#intro1.1 [2] http://www.w3.org/TR/xmlschema11-2/#intro-relatedWork [3] http://www.w3.org/TR/xmlschema11-2/#string -------------------------------------- Noah Mendelsohn IBM Corporation One Rogers Street Cambridge, MA 02142 1-617-693-4036 --------------------------------------
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] |
PURCHASE STYLUS STUDIO ONLINE TODAY!Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced! Download The World's Best XML IDE!Accelerate XML development with our award-winning XML IDE - Download a free trial today! Subscribe in XML format
|