D Implementation-Defined Items

The following items in this specification are implementation-defined:

  1. The version of Unicode that is used to construct expressions.

  2. The statically-known collations.

  3. The implicit timezone.

  4. The circumstances in which warnings are raised, and the ways in which warnings are handled.

  5. The method by which errors are reported to the external processing environment.

  6. Which version of XML and XML Names (e.g. [XML 1.0] and [XML Names] or [XML 1.1] and [XML Names 1.1]) and which version of XML Schema (e.g. [XML Schema 1.0] or [XML Schema 1.1]) is used for the definitions of primitives such as characters and names, and for the definitions of operations such as normalization of line endings and normalization of whitespace in attribute values. It is recommended that the latest applicable version be used (even if it is published later than this specification).

  7. How XDM instances are created from sources other than an Infoset or PSVI.

  8. Any components of the static context or dynamic context that are overwritten or augmented by the implementation.

  9. The default handling of empty sequences returned by an ordering key (orderspec) in an order by clause (empty least or empty greatest).

  10. The names and semantics of any extension expressions (pragmas) recognized by the implementation.

  11. The names and semantics of any option declarations recognized by the implementation.

  12. Protocols (if any) by which parameters can be passed to an external function, and the result of the function can returned to the invoking query.

  13. The process by which the specific modules to be imported by a module import are identified, if the Module Feature is supported (includes processing of location hints, if any.)

  14. The means by which serialization is invoked, if the Serialization Feature is supported.

  15. The default values for the byte-order-mark, encoding, html-version, item-separator, media-type, normalization-form, omit-xml-declaration, standalone, and version parameters, if the Serialization Feature is supported.

  16. The result of an unsuccessful call to an external function (for example, if the function implementation cannot be found or does not return a value of the declared type).

  17. Limits on ranges of values for various data types, as enumerated in 6.3 Data Model Conformance.

  18. Syntactic extensions to XQuery, including both their syntax and semantics, as discussed in 6.4 Syntax Extensions.

  19. Whether the type system is based on [XML Schema 1.0] or [XML Schema 1.1]. An implementation that has based its type system on XML Schema 1.0 is not required to support the use of the xs:dateTimeStamp constructor or the use of xs:dateTimeStamp or xs:error as TypeName in any expression.

  20. The signatures of functions provided by the implementation or via an implementation-defined API (see 2.2.1 Static Context).

  21. Any environment variables provided by the implementation.

  22. Any rules used for static typing (see 2.3.3.1 Static Analysis Phase).

  23. Any serialization parameters provided by the implementation (see 2.3.4 Serialization).

  24. The means by which the location hint for a serialization parameter document identifies the corresponding XDM instance (see 2.3.4 Serialization).

  25. What error, if any, is returned if an external function's implementation does not return the declared result type (see 2.3.5 Consistency Constraints).

  26. Any annotations defined by the implementation, and their associated behavior (see 5.15 Annotations).

  27. Any function assertions defined by the implementation.

  28. The effect of function assertions understood by the implementation on 3.7.3 The judgement subtype-assertions(AnnotationsA, AnnotationsB) .

  29. Any implementation-defined variables defined by the implementation. (see 4.3.2 Variable References).

  30. The ordering associated with fn:unordered in the implementation (see 4.16 Ordered and Unordered Expressions).

  31. Any additional information provided for try/catch via the err:additional variable (see 4.21 Try/Catch Expressions).

  32. The default boundary-space policy (see 5.3 Boundary-space Declaration).

  33. The default collation (see 5.4 Default Collation Declaration).

  34. The default base URI (see 5.5 Base URI Declaration).

Note:

Additional implementation-defined items are listed in [XQuery and XPath Data Model (XDM) 3.1] and [XQuery and XPath Functions and Operators 4.0].