Add Axiom::Types::Relation type

lib/axiom.rb

@@ -170,6 +170,7 @@ class ManyTuplesError < SetSizeError; end
 require 'axiom/relation/operation/insertion'
 
 require 'axiom-types'
+require 'axiom/types/relation'
 
 require 'axiom/attribute/comparable'
 

lib/axiom/types/relation.rb

@@ -0,0 +1,13 @@
+# encoding: utf-8
+
+module Axiom
+  module Types
+
+    # Represents a relation type
+    class Relation < Object
+
+      primitive Axiom::Relation
+
+    end # class Relation
+  end # module Types
+end # module Axiom

spec/unit/axiom/types/relation/class_methods/primitive_spec.rb

@@ -0,0 +1,13 @@
+# encoding: utf-8
+
+require 'spec_helper'
+
+describe Types::Relation, '.primitive' do
+  subject { object.primitive }
+
+  let(:object) { described_class }
+
+  it_should_behave_like 'an idempotent method'
+
+  it { should be(Relation) }
+end