Creates a RDF.Quad with proper RDF values.

An error is raised when the given elements are not coercible to RDF values.

Note: The RDF.quad function is a shortcut to this function.

Examples

iex> RDF.Quad.new {"http://example.com/S", "http://example.com/p", 42, "http://example.com/Graph"}
{~I<http://example.com/S>, ~I<http://example.com/p>, RDF.literal(42), ~I<http://example.com/Graph>}
iex> RDF.Quad.new {EX.S, EX.p, 42, EX.Graph}
{RDF.iri("http://example.com/S"), RDF.iri("http://example.com/p"), RDF.literal(42), RDF.iri("http://example.com/Graph")}

Creates a RDF.Quad with proper RDF values.

An error is raised when the given elements are not coercible to RDF values.

Note: The RDF.quad function is a shortcut to this function.

Examples

iex> RDF.Quad.new("http://example.com/S", "http://example.com/p", 42, "http://example.com/Graph")
{~I<http://example.com/S>, ~I<http://example.com/p>, RDF.literal(42), ~I<http://example.com/Graph>}
iex> RDF.Quad.new(EX.S, EX.p, 42, EX.Graph)
{RDF.iri("http://example.com/S"), RDF.iri("http://example.com/p"), RDF.literal(42), RDF.iri("http://example.com/Graph")}

Checks if the given tuple is a valid RDF quad.

The elements of a valid RDF quad must be RDF terms. On the subject position only IRIs and blank nodes allowed, while on the predicate and graph context position only IRIs allowed. The object position can be any RDF term.

Returns a tuple of native Elixir values from a RDF.Quad of RDF terms.

Returns nil if one of the components of the given tuple is not convertible via RDF.Term.value/1.

The optional second argument allows to specify a custom mapping with a function which will receive a tuple {statement_position, rdf_term} where statement_position is one of the atoms :subject, :predicate, :object or :graph_name, while rdf_term is the RDF term to be mapped. When the given function returns nil this will be interpreted as an error and will become the overhaul result of the values/2 call.

Examples

iex> RDF.Quad.values {~I<http://example.com/S>, ~I<http://example.com/p>, RDF.literal(42), ~I<http://example.com/Graph>}
{"http://example.com/S", "http://example.com/p", 42, "http://example.com/Graph"}

iex> {~I<http://example.com/S>, ~I<http://example.com/p>, RDF.literal(42), ~I<http://example.com/Graph>}
...> |> RDF.Quad.values(fn
...>      {:object, object} ->
...>        RDF.Term.value(object)
...>      {:graph_name, graph_name} ->
...>        graph_name
...>      {_, resource} ->
...>        resource |> to_string() |> String.last() |> String.to_atom()
...>    end)
{:S, :p, 42, ~I<http://example.com/Graph>}