adding Manipulate::swap

CHANGELOG.rdoc

@@ -1,6 +1,6 @@
 == 0.2.0
 * Optimized traversal functions for better performance.
-* Adding Node::is_root?, Node::is_leaf? and Manipulate::replace functions.
+* Adding Node::is_root?, Node::is_leaf?, Manipulate::replace and Manipulate::swap functions.
 
 == 0.1.5 - 2010.06.27
 * Xpath query parser was not matching leading '//axis::node' correctly. The axis was being parsed as '/axis'.

lib/rind/manipulate.rb

@@ -33,8 +33,35 @@ def remove
 	#  nodes[1].replace('y', 'z') => ['a', 'y', 'z', 'c']
 	def replace(*nodes)
 		children = self.parent.children
+
 		index = children.exact_index(self)
 		children.delete_at(index)
+
 		children.insert(index, *nodes)
 	end
+
+	# Swap <tt>self</tt> from one node set with a <tt>node</tt> from another node set.
+	# === Example
+	#  nodes = ['a', 'b', 'c']
+	#  nodes[1].swap('d') => ['a', 'd', 'c']
+	#
+	#  abc = ['a', 'b', 'c']
+	#  xyz = ['x', 'y', 'z']
+	#  abc[1].swap(xyz[1]) => ['a', 'y', 'c']
+	#  xyz => ['x', 'b', 'z']
+	def swap(node)
+		self_children = self.parent.children
+		node_children = node.parent.children
+
+		self_index = self_children.exact_index(self)
+		node_index = node_children.exact_index(node)
+
+		self_children.delete_at(self_index)
+		node_children.delete_at(node_index)
+
+		self_children.insert(self_index, node)
+		node_children.insert(node_index, self)
+
+		self_children
+	end
 end

test/manipulate_test.rb

@@ -29,4 +29,14 @@ def test_replace
 
 		assert_equal(@a.children[0].replace(c1, c2), [c1, c2, @b2, @b3])
 	end
+
+	def test_swap
+		z = Rind::Html::Z.new()
+		y1 = Rind::Html::Y.new()
+		y2 = Rind::Html::Y.new()
+		z.children.push(y1, y2)
+
+		assert_equal(@a.children[1].swap(y2), [@b1, y2, @b3])
+		assert_equal(z.children, [y1, @b2])
+	end
 end