From 69fbdd60b36374e89d20b69c35add0f2fd8e12d6 Mon Sep 17 00:00:00 2001
From: Marcel Otto <marcelotto@gmx.de>
Date: Mon, 28 Sep 2020 11:22:46 +0200
Subject: [PATCH] Add RDF.Graph.base_iri/1 and RDF.Graph.prefixes/1

---
 CHANGELOG.md             | 10 ++++++++--
 lib/rdf/graph.ex         | 12 ++++++++++++
 test/unit/graph_test.exs | 12 ++++++++++++
 3 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e8ad58c..cb6dde3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,8 +9,14 @@ 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`
+- to `RDF.Description`
+    - `RDF.Description.subject/1` 
+    - `RDF.Description.change_subject/2`
+- to `RDF.Graph`
+    - `RDF.Graph.name/1` 
+    - `RDF.Graph.change_name/2`
+    - `RDF.Graph.base_iri/1` 
+    - `RDF.Graph.prefixes/1`
 
 ### Changed
 
diff --git a/lib/rdf/graph.ex b/lib/rdf/graph.ex
index 76a3351..81efef9 100644
--- a/lib/rdf/graph.ex
+++ b/lib/rdf/graph.ex
@@ -901,6 +901,12 @@ defmodule RDF.Graph do
 
   def equal?(_, _), do: false
 
+  @doc """
+  Returns the prefixes of the given `graph` as a `RDF.PrefixMap`.
+  """
+  @spec prefixes(t) :: PrefixMap.t() | nil
+  def prefixes(%__MODULE__{} = graph), do: graph.prefixes
+
   @doc """
   Adds `prefixes` to the given `graph`.
 
@@ -955,6 +961,12 @@ defmodule RDF.Graph do
     %__MODULE__{graph | prefixes: nil}
   end
 
+  @doc """
+  Returns the base IRI of the given `graph`.
+  """
+  @spec base_iri(t) :: IRI.t() | nil
+  def base_iri(%__MODULE__{} = graph), do: graph.base_iri
+
   @doc """
   Sets the base IRI of the given `graph`.
 
diff --git a/test/unit/graph_test.exs b/test/unit/graph_test.exs
index 4eacd93..2e82c41 100644
--- a/test/unit/graph_test.exs
+++ b/test/unit/graph_test.exs
@@ -810,6 +810,11 @@ defmodule RDF.GraphTest do
            |> Graph.equal?(Graph.new({EX.S, EX.p(), EX.O}, name: EX.Graph2))
   end
 
+  test "prefixes/1" do
+    assert Graph.prefixes(graph()) == nil
+    assert %Graph{prefixes: PrefixMap.new()} |> Graph.prefixes() == PrefixMap.new()
+  end
+
   describe "add_prefixes/2" do
     test "when prefixes already exist" do
       graph = Graph.new(prefixes: %{xsd: XSD}) |> Graph.add_prefixes(ex: EX)
@@ -857,6 +862,13 @@ defmodule RDF.GraphTest do
     assert Graph.clear_prefixes(Graph.new(prefixes: %{ex: EX})) == Graph.new()
   end
 
+  test "base_iri/1" do
+    assert Graph.base_iri(graph()) == nil
+
+    assert %Graph{base_iri: ~I<http://example.com/>} |> Graph.base_iri() ==
+             ~I<http://example.com/>
+  end
+
   describe "set_base_iri/1" do
     test "when given an IRI" do
       graph = Graph.new() |> Graph.set_base_iri(~I<http://example.com/>)