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Predicate rdf/3 |
Triples consist of the following three terms:
Alias:Local
, where Alias and
Local are atoms. Each abbreviated IRI is expanded by the
system to a full IRI.Datatype IRI | Prolog term |
---|---|
xsd:float | float |
xsd:double | float |
xsd:decimal | float (1) |
xsd:integer | integer |
XSD integer sub-types | integer |
xsd:boolean | true or false |
xsd:date | date(Y,M,D) |
xsd:dateTime | date_time(Y,M,D,HH,MM,SS) (2,3) |
xsd:gDay | integer |
xsd:gMonth | integer |
xsd:gMonthDay | month_day(M,D) |
xsd:gYear | integer |
xsd:gYearMonth | year_month(Y,M) |
xsd:time | time(HH,MM,SS) (2) |
Notes:
(1) The current implementation of xsd:decimal
values
as floats is formally incorrect. Future versions
of SWI-Prolog may introduce decimal as a subtype
of rational.
(2) SS fields denote the number of seconds. This can either be an integer or a float.
(3) The date_time
structure can have a 7th field that
denotes the timezone offset in seconds as an
integer.
In addition, a ground object value is translated into a properly typed RDF literal using rdf_canonical_literal/2.
There is a fine distinction in how duplicate statements are handled in rdf/[3,4]: backtracking over rdf/3 will never return duplicate triples that appear in multiple graphs. rdf/4 will return such duplicate triples, because their graph term differs.
S | - is the subject term. It is either a blank node or IRI. |
P | - is the predicate term. It is always an IRI. |
O | - is the object term. It is either a literal, a blank
node or IRI (except for true and false that denote the
values of datatype XSD boolean). |
G | - is the graph term. It is always an IRI. |