F.1 Implementation-Defined Items
The following items are
implementation-defined.
- Support for additional user-defined or
implementation-defined types is implementation-defined. (See 2.8.1 Representation of Types)
- When converting from an
xs:string
to an xs:float
or
xs:double
, it is implementation-defined whether the
lexical value “-0” (and similar forms such as “-0.0”) convert to
negative zero or to positive zero in the value space. (See 2.8.7 Negative Zero)
- Data model construction from sources other than
an Infoset or PSVI is implementation-defined. (See 3 Data Model Construction)
- Some typed values in the data model are absent.
Attempting to access an absent typed value is an error. Behavior
in these cases is implementation-defined and the host language is responsible
for determining the result. (See 5 Accessors)