2.4.3 Datatypes




With one exception, the datatypes used in RDF have a lexical space consisiting of a set of strings. The exception is rdfs:XMLLiteral, whose lexical space is a set of pairs of strings and language identifiers, and the value obtained through its datatype mapping depends on the language identifier.


Value Space {T, F}

RDF predefines just one datatype rdfs:XMLLiteral, used for embedding XML in RDF (see section 3).

There is no built-in concept of numbers or dates or other common values. Rather, RDF defers to datatypes that are defined separately, and identified with URIs.The predefined XML Schema datatypes [XML-SCHEMA2] are expected to be widely used for this purpose. The defining authority of a URI which identifies a datatype is responsible for specifying the datatype's lexical space, value space and datatype mapping.


2.4.4 Literals


A literal may label the object of an RDF statement, but not the subject or the arc.

Literals may be typed or untyped:

[[[Need to check WG outcome of no lang id vs empty lang id debate]]]

Continuing the example from section 2.4.3, the typed literals which can be defined using the XML Schema datatype xsd:boolean are:

Typed Literal Datatype Mapping Value