XML News from Thursday, December 3, 2009

The W3C XML Schema Working Group has sent XML Schema 1.1 Part 1: Structures and XML Schema Definition Language (XSD) 1.1 Part 2: Datatypes back to last call. According to the data types draft,

The major changes since version 1.0 include:

• Support for XML 1.1 has been added. It is now implementation defined whether datatypes dependent on definitions in [XML] and [Namespaces in XML] use the definitions as found in version 1.1 or version 1.0 of those specifications.
• A new primitive decimal type has been defined, which retains information about the precision of the value. This type is aligned with the floating-point decimal types which are included in [IEEE 754-2008].
• In order to align this specification with those being prepared by the XSL and XML Query Working Groups, a new datatype named anyAtomicType which serves as the base type definition for all primitive atomic datatypes has been introduced.
• The conceptual model of the date- and time-related types has been defined more formally.
• A more formal treatment of the fundamental facets of the primitive datatypes has been adopted.
• More formal definitions of the lexical space of most types have been provided, with detailed descriptions of the mappings from lexical representation to value and from value to ·canonical representation·.
• The validation rule Datatype Valid (§4.1.4) has been recast in more declarative form. A paraphrase of the constraint in procedural terms, which corrects some errors in the previous versions of this document, has been added as a note.
• The rules governing partial implementations of infinite datatypes have been clarified.
• Various changes have been made in order to align the relevant parts of this specification more closely with other relevant specifications, including especially the corresponding sections of [XSD 1.1 Part 1: Structures].