Method step_do

src/include/pugixml.cpp:7934–7980

		}
		
		template <class T> xpath_node_set_raw step_do(const xpath_context& c, const xpath_stack& stack, T v)
		{
			const axis_t axis = T::axis;
			bool attributes = (axis == axis_ancestor || axis == axis_ancestor_or_self || axis == axis_descendant_or_self || axis == axis_following || axis == axis_parent || axis == axis_preceding || axis == axis_self);

			xpath_node_set_raw ns;
			ns.set_type((axis == axis_ancestor || axis == axis_ancestor_or_self || axis == axis_preceding || axis == axis_preceding_sibling) ? xpath_node_set::type_sorted_reverse : xpath_node_set::type_sorted);

			if (_left)
			{
				xpath_node_set_raw s = _left->eval_node_set(c, stack);

				// self axis preserves the original order
				if (axis == axis_self) ns.set_type(s.type());

				for (const xpath_node* it = s.begin(); it != s.end(); ++it)
				{
					size_t size = ns.size();

					// in general, all axes generate elements in a particular order, but there is no order guarantee if axis is applied to two nodes
					if (axis != axis_self && size != 0) ns.set_type(xpath_node_set::type_unsorted);
					
					if (it->node())
						step_fill(ns, it->node(), stack.result, v);
					else if (attributes)
						step_fill(ns, it->attribute(), it->parent(), stack.result, v);
						
					apply_predicates(ns, size, stack);
				}
			}
			else
			{
				if (c.n.node())
					step_fill(ns, c.n.node(), stack.result, v);
				else if (attributes)
					step_fill(ns, c.n.attribute(), c.n.parent(), stack.result, v);
				
				apply_predicates(ns, 0, stack);
			}

			// child, attribute and self axes always generate unique set of nodes
			// for other axis, if the set stayed sorted, it stayed unique because the traversal algorithms do not visit the same node twice
			if (axis != axis_child && axis != axis_attribute && axis != axis_self && ns.type() == xpath_node_set::type_unsorted)
				ns.remove_duplicates();

			return ns;
		}
		
	public:
		xpath_ast_node(ast_type_t type, xpath_value_type rettype_, const char_t* value):