core: add __uris__ to vocabulary namespaces which returns all URIs of the vocabulary

lib/rdf/vocabulary_namespace.ex

@@ -78,7 +78,19 @@ defmodule RDF.Vocabulary.Namespace do
         def __strict__, do: @strict
 
         @terms unquote(Macro.escape(terms))
-        def __terms__, do: @terms  |> Map.keys
+        def __terms__, do: @terms |> Map.keys
+
+        @doc """
+        Returns all known URIs of the vocabulary.
+        """
+        def __uris__ do
+          @terms
+          |> Enum.map(fn
+               {term, true}   -> term_to_uri(@base_uri, term)
+               {_alias, term} -> term_to_uri(@base_uri, term)
+             end)
+          |> Enum.uniq
+        end
 
         define_vocab_terms unquote(lowercased_terms), unquote(base_uri)
 

test/unit/vocabulary_namespace_test.exs

@@ -217,6 +217,20 @@ defmodule RDF.Vocabulary.NamespaceTest do
     end
   end
 
+  test "__uris__ returns all URIs of the vocabulary" do
+    alias TestNS.{Example1, Example5}
+    assert length(Example1.__uris__) == 2
+    assert RDF.uri(Example1.foo) in Example1.__uris__
+    assert RDF.uri(Example1.Bar) in Example1.__uris__
+
+    assert length(Example5.__uris__) == 4
+    assert RDF.uri(Example5.Term1) in Example5.__uris__
+    assert RDF.uri(Example5.term2) in Example5.__uris__
+    assert RDF.uri(Example5.Term3) in Example5.__uris__
+    assert RDF.uri(Example5.term4) in Example5.__uris__
+  end
+
+
   describe "invalid character handling" do
     test "when a term contains unallowed characters and no alias defined, it fails when invalid_characters = :fail" do
       assert_raise RDF.Namespace.InvalidTermError, ~r/Foo-bar.*foo-bar/s,