Add RDF.Graph.name/1 and RDF.Graph.change_name/2

CHANGELOG.md

@@ -10,6 +10,7 @@ This project adheres to [Semantic Versioning](http://semver.org/) and
 ### Added
 
 - `RDF.Description.subject/1` and `RDF.Description.change_subject/2`
+- `RDF.Graph.name/1` and `RDF.Graph.change_name/2`
 
 ### Changed
 

lib/rdf/description.ex

@@ -79,11 +79,13 @@ defmodule RDF.Description do
   @doc """
   Returns the subject IRI or blank node of a description.
   """
+  @spec subject(t) :: RDF.Statement.subject()
   def subject(%__MODULE__{} = description), do: description.subject
 
   @doc """
   Changes the subject of a description.
   """
+  @spec change_subject(t, RDF.Statement.coercible_subject()) :: t
   def change_subject(%__MODULE__{} = description, new_subject) do
     %__MODULE__{description | subject: coerce_subject(new_subject)}
   end

lib/rdf/graph.ex

@@ -17,6 +17,8 @@ defmodule RDF.Graph do
   import RDF.Utils
   alias RDF.{Description, IRI, PrefixMap, Statement}
 
+  defstruct name: nil, descriptions: %{}, prefixes: nil, base_iri: nil
+
   @type graph_description :: %{Statement.subject() => Description.t()}
 
   @type t :: %__MODULE__{
@@ -45,8 +47,6 @@ defmodule RDF.Graph do
 
   @type get_and_update_description_fun :: (Description.t() -> {Description.t(), input} | :pop)
 
-  defstruct name: nil, descriptions: %{}, prefixes: nil, base_iri: nil
-
   @doc """
   Creates an empty unnamed `RDF.Graph`.
   """
@@ -138,6 +138,20 @@ defmodule RDF.Graph do
     %__MODULE__{graph | descriptions: %{}}
   end
 
+  @doc """
+  Returns the graph name IRI of `graph`.
+  """
+  @spec name(t) :: RDF.Statement.graph_name()
+  def name(%__MODULE__{} = graph), do: graph.name
+
+  @doc """
+  Changes the graph name of `graph`.
+  """
+  @spec change_name(t, RDF.Statement.coercible_graph_name()) :: t
+  def change_name(%__MODULE__{} = graph, new_name) do
+    %__MODULE__{graph | name: coerce_graph_name(new_name)}
+  end
+
   @doc """
   Adds triples to a `RDF.Graph`.
 

lib/rdf/serializations/nquads_encoder.ex

@@ -3,7 +3,7 @@ defmodule RDF.NQuads.Encoder do
 
   use RDF.Serialization.Encoder
 
-  alias RDF.{Dataset, Graph, Quad, Statement, Triple}
+  alias RDF.{Dataset, Graph, Statement}
 
   @impl RDF.Serialization.Encoder
   @callback encode(Graph.t() | Dataset.t(), keyword | map) :: {:ok, String.t()} | {:error, any}
@@ -17,18 +17,17 @@ defmodule RDF.NQuads.Encoder do
     {:ok, if(result == "", do: result, else: "#{result}\n")}
   end
 
-  @spec statement({Statement.subject(), Statement.predicate(), Statement.object(), nil}) ::
-          String.t()
+  @spec statement(Statement.t()) :: String.t()
+  def statement(statement)
+
   def statement({subject, predicate, object, nil}) do
     statement({subject, predicate, object})
   end
 
-  @spec statement(Quad.t()) :: String.t()
   def statement({subject, predicate, object, graph}) do
     "#{term(subject)} #{term(predicate)} #{term(object)} #{term(graph)} ."
   end
 
-  @spec statement(Triple.t()) :: String.t()
   def statement({subject, predicate, object}) do
     "#{term(subject)} #{term(predicate)} #{term(object)} ."
   end

lib/rdf/statement.ex

@@ -11,7 +11,7 @@ defmodule RDF.Statement do
   @type subject :: IRI.t() | BlankNode.t()
   @type predicate :: IRI.t() | BlankNode.t()
   @type object :: IRI.t() | BlankNode.t() | Literal.t()
-  @type graph_name :: IRI.t() | BlankNode.t()
+  @type graph_name :: IRI.t() | BlankNode.t() | nil
 
   @type coercible_subject :: subject | atom | String.t()
   @type coercible_predicate :: predicate | atom | String.t()

test/unit/graph_test.exs

@@ -165,6 +165,15 @@ defmodule RDF.GraphTest do
            |> Graph.clear() == Graph.new(opts)
   end
 
+  test "name/1" do
+    assert Graph.name(graph()) == graph().name
+  end
+
+  test "change_name/2" do
+    assert Graph.change_name(graph(), EX.NewGraph).name == iri(EX.NewGraph)
+    assert Graph.change_name(named_graph(), nil).name == nil
+  end
+
   describe "add/2" do
     test "a proper triple" do
       assert Graph.add(graph(), {iri(EX.Subject), EX.predicate(), iri(EX.Object)})