RDF.XSD.Datatype behaviour (RDF.ex v0.9.0) View Source
A behaviour for XSD datatypes.
A XSD datatype has three properties:
- A value space, which is a set of values.
- A lexical space, which is a set of literals used to denote the values.
- A collection of functions associated with the datatype.
Builtin XSD datatypes
RDF.ex comes with the following builtin implementations of XSD datatypes:
xsd:boolean | RDF.XSD.Boolean |
xsd:float | RDF.XSD.Float |
xsd:double | RDF.XSD.Double |
xsd:decimal | RDF.XSD.Decimal |
xsd:integer | RDF.XSD.Integer |
xsd:long | RDF.XSD.Long |
xsd:int | RDF.XSD.Int |
xsd:short | RDF.XSD.Short |
xsd:byte | RDF.XSD.Byte |
xsd:nonPositiveInteger | RDF.XSD.NonPositiveInteger |
xsd:negativeInteger | RDF.XSD.NegativeInteger |
xsd:nonNegativeInteger | RDF.XSD.NonNegativeInteger |
xsd:positiveInteger | RDF.XSD.PositiveInteger |
xsd:unsignedLong | RDF.XSD.UnsignedLong |
xsd:unsignedInt | RDF.XSD.UnsignedInt |
xsd:unsignedShort | RDF.XSD.UnsignedShort |
xsd:unsignedByte | RDF.XSD.UnsignedByte |
xsd:string | RDF.XSD.String |
xsd:normalizedString | ❌ |
xsd:token | ❌ |
xsd:language | ❌ |
xsd:Name | ❌ |
xsd:NCName | ❌ |
xsd:ID | ❌ |
xsd:IDREF | ❌ |
xsd:ENTITY | ❌ |
xsd:NMTOKEN | ❌ |
xsd:dateTime | RDF.XSD.DateTime |
xsd:dateTimeStamp | ❌ |
xsd:date | RDF.XSD.Date |
xsd:time | RDF.XSD.Time |
xsd:duration | ❌ |
xsd:dayTimeDuration | ❌ |
xsd:yearMonthDuration | ❌ |
xsd:gYearMonth | ❌ |
xsd:gYear | ❌ |
xsd:gMonthDay | ❌ |
xsd:gDay | ❌ |
xsd:gMonth | ❌ |
xsd:base64Binary | ❌ |
xsd:hexBinary | ❌ |
xsd:anyURI | RDF.XSD.AnyURI |
xsd:QName | ❌ |
xsd:NOTATION | ❌ |
There are some notable difference in the implementations of some datatypes compared to the original spec:
RDF.XSD.Integer
is not derived fromRDF.XSD.Decimal
, but implemented as a primitive datatypeRDF.XSD.Float
is not implemented as a primitive datatype, but derived fromRDF.XSD.Double
without further restrictions instead, since Erlang doesn't have a corresponding datatype
Link to this section Summary
Functions
Returns the RDF.XSD.Datatype
for a datatype IRI.
Callbacks
The set of applicable facets of a RDF.XSD.Datatype
.
The base datatype from which a RDF.XSD.Datatype
is derived.
The primitive RDF.XSD.Datatype
from which a RDF.XSD.Datatype
is derived.
Returns the standard lexical representation for a value of the value space of a RDF.XSD.Datatype
.
Checks if the RDF.XSD.Datatype
is directly or indirectly derived from the given RDF.XSD.Datatype
.
A mapping from Elixir values into the value space of a RDF.XSD.Datatype
.
Produces the lexical representation of an invalid value.
Produces the lexical representation to be used for a RDF.XSD.Datatype
literal.
A mapping from the lexical space of a RDF.XSD.Datatype
into its value space.
Returns if the RDF.XSD.Datatype
is a primitive datatype.
Link to this section Types
Specs
literal() :: %t(){value: any(), uncanonical_lexical: uncanonical_lexical()}
Specs
t() :: module()
Specs
uncanonical_lexical() :: String.t() | nil
Link to this section Functions
Returns the RDF.XSD.Datatype
for a datatype IRI.
Link to this section Callbacks
Specs
applicable_facets() :: [RDF.XSD.Facet.t()]
The set of applicable facets of a RDF.XSD.Datatype
.
Specs
base() :: t() | nil
The base datatype from which a RDF.XSD.Datatype
is derived.
Note: Since this library focuses on atomic types and the special xsd:anyAtomicType
specified as the base type of all primitive types in the W3C spec wouldn't serve any
purpose here, all primitive datatypes just return nil
instead.
Specs
base_primitive() :: t()
The primitive RDF.XSD.Datatype
from which a RDF.XSD.Datatype
is derived.
In case of a primitive RDF.XSD.Datatype
this function returns this RDF.XSD.Datatype
itself.
Specs
Returns the standard lexical representation for a value of the value space of a RDF.XSD.Datatype
.
Specs
Checks if the RDF.XSD.Datatype
is directly or indirectly derived from the given RDF.XSD.Datatype
.
Note that this is just a basic datatype reflection function on the module level
and does not work with RDF.Literal
s. See RDF.Literal.Datatype.datatype?/1
instead.
Specs
elixir_mapping(any(), Keyword.t()) :: any() | {any(), uncanonical_lexical()}
A mapping from Elixir values into the value space of a RDF.XSD.Datatype
.
If the Elixir mapping for the given value can not be mapped into value space of
the XSD datatype an implementation should return @invalid_value
(which is just nil
at the moment, so nil
is never a valid value of a value space).
Otherwise a tuple {value, lexical}
with value
being the internal representation
of the mapped value from the value space and lexical
being the lexical representation
to be used for the Elixir value or nil
if init_valid_lexical/3
should be used
to determine the lexical form in general (i.e. also when initialized with a string
via the lexical_mapping/2
). Since the later case is most often what you want,
you can also return value
directly, as long as it is not a two element tuple.
Specs
Produces the lexical representation of an invalid value.
The default implementation of the _using__
macro just returns the to_string/1
representation of the value.
Specs
init_valid_lexical(any(), uncanonical_lexical(), Keyword.t()) :: uncanonical_lexical()
Produces the lexical representation to be used for a RDF.XSD.Datatype
literal.
By default the lexical representation of a RDF.XSD.Datatype
is either the
canonical form in case it is created from a non-string Elixir value or, if it
is created from a string, just with that string as the lexical form.
But there can be various reasons for why this should be different for certain
datatypes. For example, for RDF.XSD.Double
s given as Elixir floats, we want the
default lexical representation to be the decimal and not the canonical
exponential form. Another reason might be that additional options are given
which should be taken into account in the lexical form.
If the lexical representation for a given value
and lexical
should be the
canonical one, an implementation should return nil
.
Specs
A mapping from the lexical space of a RDF.XSD.Datatype
into its value space.
Specs
primitive?() :: boolean()
Returns if the RDF.XSD.Datatype
is a primitive datatype.