diff --git a/lib/oga/xpath/evaluator.rb b/lib/oga/xpath/evaluator.rb
index 3079104..a112d04 100644
--- a/lib/oga/xpath/evaluator.rb
+++ b/lib/oga/xpath/evaluator.rb
@@ -307,6 +307,27 @@ module Oga
return nodes
end
+ ##
+ # Evaluates the `parent` axis.
+ #
+ # @param [Oga::XPath::Node] ast_node
+ # @param [Oga::XML::NodeSet] context
+ # @return [Oga::XML::NodeSet]
+ #
+ def on_axis_parent(ast_node, context)
+ nodes = XML::NodeSet.new
+
+ context.each do |context_node|
+ next unless has_parent?(context_node)
+
+ parent = context_node.parent
+
+ nodes << parent if node_matches?(parent, ast_node)
+ end
+
+ return nodes
+ end
+
##
# Returns a node set containing all the child nodes of the given set of
# nodes.
diff --git a/spec/oga/xpath/evaluator/axes/parent_spec.rb b/spec/oga/xpath/evaluator/axes/parent_spec.rb
new file mode 100644
index 0000000..26eb34e
--- /dev/null
+++ b/spec/oga/xpath/evaluator/axes/parent_spec.rb
@@ -0,0 +1,42 @@
+require 'spec_helper'
+
+describe Oga::XPath::Evaluator do
+ context 'parent axis' do
+ before do
+ @document = parse('')
+ @evaluator = described_class.new(@document)
+ end
+
+ context 'matching nodes without parents' do
+ before do
+ @set = @evaluator.evaluate('parent::a')
+ end
+
+ it_behaves_like :empty_node_set
+ end
+
+ context 'matching nodes with parents' do
+ before do
+ @set = @evaluator.evaluate('a/b/parent::a')
+ end
+
+ it_behaves_like :node_set, :length => 1
+
+ example 'return the node' do
+ @set[0].should == @document.children[0]
+ end
+ end
+
+ context 'matching nodes with parents using the short axis form' do
+ before do
+ @set = @evaluator.evaluate('a/b/parent::node()')
+ end
+
+ it_behaves_like :node_set, :length => 1
+
+ example 'return the node' do
+ @set[0].should == @document.children[0]
+ end
+ end
+ end
+end