43 lines
951 B
Elixir
43 lines
951 B
Elixir
defmodule RDF.BlankNode do
|
|
@moduledoc """
|
|
An RDF blank node, also known as an anonymous or unlabeled node.
|
|
|
|
see <https://www.w3.org/TR/rdf11-primer/#section-blank-node>
|
|
and <https://www.w3.org/TR/rdf11-concepts/#section-blank-nodes>
|
|
"""
|
|
|
|
defstruct [:id]
|
|
|
|
@type t :: module
|
|
|
|
@doc """
|
|
Generator function for `RDF.BlankNode`s.
|
|
"""
|
|
def new,
|
|
do: new(make_ref())
|
|
|
|
@doc """
|
|
Generator function for `RDF.BlankNode`s with a user-defined identity.
|
|
|
|
## Examples
|
|
|
|
iex> RDF.bnode(:foo)
|
|
%RDF.BlankNode{id: "foo"}
|
|
"""
|
|
def new(id)
|
|
|
|
def new(id) when is_binary(id),
|
|
do: %RDF.BlankNode{id: id}
|
|
|
|
def new(id) when is_reference(id),
|
|
do: id |> :erlang.ref_to_list |> to_string |> String.replace(~r/\<|\>/, "") |> new
|
|
|
|
def new(id) when is_atom(id) or is_integer(id),
|
|
do: id |> to_string |> new
|
|
end
|
|
|
|
defimpl String.Chars, for: RDF.BlankNode do
|
|
def to_string(%RDF.BlankNode{id: id}) do
|
|
"_:#{id}"
|
|
end
|
|
end
|