Returns the canonical lexical form of a RDF.Literal of this datatype.

Specs

cast(RDF.Literal.Datatype.literal() | RDF.Term.t()) :: RDF.Literal.t() | nil

Casts a datatype literal of one type into a datatype literal of another type.

Returns nil when the given arguments are not castable into this datatype or when the given argument is an invalid literal.

Implementations define the casting for a given value with the RDF.Literal.Datatype.do_cast/1 callback.

Specs

compare(RDF.Literal.t() | any(), RDF.Literal.t() | any()) ::
  RDF.Literal.Datatype.comparison_result() | :indeterminate | nil

Checks if the given literal has this datatype.

Checks if two datatype literals are equal in terms of the values of their value space.

Non-RDF.Literals are tried to be coerced via RDF.Literal.coerce/1 before comparison.

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

Invalid literals are only considered equal in this relation when both have the exact same datatype and the same attributes (lexical form, language etc.).

Implementations can customize this equivalence relation via the RDF.Literal.Datatype.do_equal_value_different_datatypes?/2 and RDF.Literal.Datatype.do_equal_value_different_datatypes?/2 callbacks.

Specs

match_language?(RDF.Literal.t() | t() | String.t(), String.t()) :: boolean()

Checks if a language tagged string literal or language tag matches a language range.

The check is performed per the basic filtering scheme defined in RFC4647 section 3.3.1. A language range is a basic language range per Matching of Language Tags in RFC4647 section 2.1. A language range of "*" matches any non-empty language-tag string.

see https://www.w3.org/TR/sparql11-query/#func-langMatches

Specs

new(any(), String.t() | atom() | keyword()) :: RDF.Literal.t()

Creates a new RDF.Literal with this datatype and the given value and language.

Updates the value of a RDF.Literal without changing everything else.