Indexing of NodeSet instances.

Similar to arrays the NodeSet class now allows one to retrieve nodes for a
given index.

lib/oga/xml/node_set.rb

@@ -103,6 +103,16 @@ module Oga
         return @nodes.pop
       end
 
+      ##
+      # Returns the node for the given index.
+      #
+      # @param [Fixnum] index
+      # @return [Oga::XML::Node]
+      #
+      def [](index)
+        return @nodes[index]
+      end
+
       ##
       # Removes the current nodes from their owning set. The nodes are *not*
       # removed from the current set.

spec/oga/xml/node_set_spec.rb

@@ -128,6 +128,17 @@ describe Oga::XML::NodeSet do
     end
   end
 
+  context '#[]' do
+    before do
+      @n1  = Oga::XML::Element.new(:name => 'a')
+      @set = described_class.new([@n1])
+    end
+
+    example 'return a node from a given index' do
+      @set[0].should == @n1
+    end
+  end
+
   context '#remove' do
     before do
       @n1  = Oga::XML::Element.new(:name => 'a')