- From: Boris Motik <boris.motik@comlab.ox.ac.uk>
- Date: Tue, 29 Jul 2008 10:23:24 -0400
- To: <public-owl-wg@w3.org>

Hello, This is the proposal for the datatype system of OWL 2 worked out at 3F2F. Regards, Boris 1. Numeric Datatypes ---------------------- Datatype: owl:realPlus Value space: The set of all real numbers plus NaN, +inf, -inf, and -0. Facets: minInclusive, minExclusive, maxInclusive, and maxExclusive Constants: None Note 1: The value +0 is already available in the set of all real numbers. Note 2: This is the base datatype for all other numeric datatypes. Note 3: The facets are inherited by all numeric datatypes and I don't list them separately. Datatype: owl:real Value space: The set of all real numbers (without NaN, +inf, -inf, and -0). Constants: None Note: The value space is a subset of owl:realPlus. Datatype: xsd:integer Value space: The set of all integers. The value space is the subset of owl:number. Constants: The same as in XML Schema. The normative requirement would be to support all two's complement 64 bit integers. Note: We would also support all the derivatives of xsd:integer, which I won't list separately. Datatype: xsd:float and xsd:double Value space: The discrete set of all floats (resp. doubles) representable using the XML Schema spec (including NaN, +inf, -inf, and -0). Constants: The same as in XML Schema. Note: Thus, the value space is a finite subset of owl:realPlus, but not of owl:number (because of the special values). Datatype: xsd:decimal Value space: The subset of owl:real containing all decimal numbers. Constants: The same as in XML Schema. The normative requirement for implementations would be to support constants as in XML Schema (which is, I think, all constants with 18 digits). 2. Additional datatypes ------------------------- The value space would be disjoint from all other datatypes. Datatype: xsd:boolean Value space: The set { true, false }. Facets: none Datatype: xsd:hexBinary Value space: The set of all finite string of octets (= bytes). Facets: length, minLength, maxLength Datatype: xsd:base64Binary Value space: Exactly the same set as in the case of xsd:hexBinary Facets: length, minLength, maxLength Note: This datatype exists only to allow for BASE64-encoded constants. 3. Time and date ------------------ Datatype: xsd:dateTime Value space: The time line as in the XML Schema 1.1. It is domain-zone independent; that is, it represents the global (i.e., "universe") time. Constants: Only constants containing the time zone are allowed. Applications may repair missing time zones in some nonstandard way. Facets: minInclusive, minExclusive, maxInclusive, and maxExclusive Note: We deferred the issue whether this is going to be called owl:dateTime instead of xsd:dateTime. 4. String datatypes --------------------- Deferred to a separate subgroup.

Received on Tuesday, 29 July 2008 14:25:08 UTC