8.3 Semantics of Data Types

   Data types in MOF meta-models fall into two groups:

• MOF standard technology neutral data types; that is, the 6 standard primitive data types (Boolean, Integer, Long, Float, Double, and String) and those produced using the constructors EnumerationType, CollectionType, StructureType, and AliasType.

• Native types (i.e., other data types. Native data types are not technology neutral).

   Each data type in a MOF meta-model denotes a finite or infinite set of values. In the case of the standard technology neutral MOF data types and constructors, these sets are as follows:

• The type Boolean consists of two values that are conventionally called “true? and “false.?

• The type Integer is the subrange of integers from -231 to +231 - 1.

• The type Long is the subrange of integers from -263 to +263 - 1.

• The type Float is the the subrange of the rational numbers whose values are AIEEE 764 single precision floating point numbers.

• The type Double is the subrange of the rational numbers whose values are IEEE 764 double precision floating point numbers.

• The type String is the set of all possible finite length sequences of the UTF16 characters (excluding the NUL or zero character).

• An enumeration type is the set of the EnumerationType labels or enumerators.

• A structure type is the set of all tuples whose field values are members of the types of the StructureType’s respective StructureFields.

• A collection type is the set of all collections of the CollectionType’s type, limited according to the CollectionType’s multiplicity.

• An alias type is a subset of the AliasType’s type.

   NOTE: Every MOF technology mapping must define a mapping from the standard MOF technology neutral data types to a concrete type such that every value in the value domain has a distinct representation using the concrete type. A technology mapping that does not support all of the data types, or that maps them in a way that loses information is not valid.

   It is not possible to define the sets of values that comprise native types in a technology independent way.