RDF.ex

v0.5.4

RDF.ex v0.5.4 RDF.Datatype behaviour View Source

A behaviour for natively supported literal datatypes.

A RDF.Datatype implements the foundational functions for the lexical form, the validation, conversion and canonicalization of typed RDF.Literals.

Link to this section Summary

Functions

get(id)

Returns the RDF.Datatype for a directly datatype IRI or the datatype IRI of a RDF.Literal

ids()

The IRIs of all datatypes with a RDF.Datatype defined

mapping()

The mapping of IRIs of datatypes to their RDF.Datatype

modules()

All defined RDF.Datatype modules

Callbacks

canonical(arg0)

Produces the canonical form of a RDF.Literal

canonical_lexical(any)

Produces the lexical form of a value

cast(arg0)

Casts a literal of another datatype into a literal of the datatype the function is implemented on

compare(literal1, literal2)

Compares two RDF.Literals

convert(any, keyword)

Converts a value into a proper native value

equal_value?(literal1, literal2)

Checks if the value of two RDF.Literals of this datatype are equal

id()

The IRI of the datatype

invalid_lexical(any)

Produces the lexical form of an invalid value of a typed Literal

lexical(literal)

Produces the lexical form of a RDF.Literal

valid?(literal)

Determines if the value of a RDF.Literal is a member of lexical value space of its datatype

Link to this section Functions

Link to this function get(id) View Source

Returns the RDF.Datatype for a directly datatype IRI or the datatype IRI of a RDF.Literal.

Link to this function ids() View Source

The IRIs of all datatypes with a RDF.Datatype defined.

Link to this function mapping() View Source

The mapping of IRIs of datatypes to their RDF.Datatype.

Link to this section Callbacks

Link to this callback canonical(arg0) View Source 
canonical(RDF.Literal.t()) :: RDF.Literal.t()

Produces the canonical form of a RDF.Literal.

Link to this callback canonical_lexical(any) View Source 
canonical_lexical(any()) :: binary()

Produces the lexical form of a value.

Link to this callback cast(arg0) View Source 
cast(RDF.Literal.t()) :: RDF.Literal.t()

Casts a literal of another datatype into a literal of the datatype the function is implemented on.

If the given literal is invalid or can not be converted into this datatype nil is returned.

Link to this callback compare(literal1, literal2) View Source 
compare(literal1 :: RDF.Literal.t(), literal2 :: RDF.Literal.t()) ::
  :lt | :gt | :eq | :indeterminate | nil

Compares two RDF.Literals.

Returns :gt if first literal is greater than the second in terms of their datatype and :lt for vice versa. If the two literals are equal :eq is returned. For datatypes with only partial ordering :indeterminate is returned when the order of the given literals is not defined.

Returns nil when the given arguments are not comparable datatypes or if one them is invalid.

The default implementation of the _using__ macro compares the values of the canonical/1 forms of the given literals of this datatype.

Link to this callback convert(any, keyword) View Source 
convert(any(), keyword()) :: any()

Converts a value into a proper native value.

If an invalid value is given an implementation should call super, which by default currently just returns nil.

Note: If a value is valid is determined by the lexical space of the implemented datatype, not by the Elixir semantics. For example, although 42 is a falsy value according to the Elixir semantics, this is not an element of the lexical value space of an xsd:boolean, so the RDF.Boolean implementation of this datatype calls super.

Link to this callback equal_value?(literal1, literal2) View Source 
equal_value?(literal1 :: RDF.Literal.t(), literal2 :: RDF.Literal.t()) ::
  boolean() | nil

Checks if the value of two RDF.Literals of this datatype are equal.

Non-RDF terms are tried to be coerced via RDF.Term.coerce/1 before comparison.

Returns nil when the given arguments are not comparable as literals of this datatype.

The default implementation of the _using__ macro compares the values of the canonical/1 forms of the given literals of this datatype.

Link to this callback id() View Source 
id() :: RDF.IRI.t()

The IRI of the datatype.

Link to this callback invalid_lexical(any) View Source 
invalid_lexical(any()) :: binary()

Produces the lexical form of an invalid value of a typed Literal.

The default implementation of the _using__ macro just returns to_string representation of the value.

Link to this callback lexical(literal) View Source 
lexical(literal :: RDF.Literal.t()) :: any()

Produces the lexical form of a RDF.Literal.

Link to this callback valid?(literal) View Source 
valid?(literal :: RDF.Literal.t()) :: boolean()

Determines if the value of a RDF.Literal is a member of lexical value space of its datatype.