Change xml_named_node_iterator to be bidirectional and to match xml_node_iterator in terms of internals

git-svn-id: http://pugixml.googlecode.com/svn/trunk@960 99668b35-9821-0410-8761-19e4c4f06640

3 files changed, 81 insertions, 38 deletions

diff --git a/src/pugixml.cpp b/src/pugixml.cpp
index 848b4cb..149b5d9 100644
--- a/src/pugixml.cpp
+++ b/src/pugixml.cpp
@@ -4038,7 +4038,7 @@ namespace pugi
 
 	PUGI__FN xml_object_range<xml_named_node_iterator> xml_node::children(const char_t* name_) const
 	{
-		return xml_object_range<xml_named_node_iterator>(xml_named_node_iterator(child(name_), name_), xml_named_node_iterator());
+		return xml_object_range<xml_named_node_iterator>(xml_named_node_iterator(child(name_)._root, _root, name_), xml_named_node_iterator(0, _root, name_));
 	}
 
 	PUGI__FN xml_object_range<xml_attribute_iterator> xml_node::attributes() const
@@ -5133,36 +5133,40 @@ namespace pugi
 	{
 	}
 
-	PUGI__FN xml_named_node_iterator::xml_named_node_iterator(const xml_node& node, const char_t* name): _node(node), _name(name)
+	PUGI__FN xml_named_node_iterator::xml_named_node_iterator(const xml_node& node, const char_t* name): _wrap(node), _parent(node.parent()), _name(name)
+	{
+	}
+
+	PUGI__FN xml_named_node_iterator::xml_named_node_iterator(xml_node_struct* ref, xml_node_struct* parent, const char_t* name): _wrap(ref), _parent(parent), _name(name)
 	{
 	}
 
 	PUGI__FN bool xml_named_node_iterator::operator==(const xml_named_node_iterator& rhs) const
 	{
-		return _node == rhs._node;
+		return _wrap._root == rhs._wrap._root && _parent._root == rhs._parent._root;
 	}
 
 	PUGI__FN bool xml_named_node_iterator::operator!=(const xml_named_node_iterator& rhs) const
 	{
-		return _node != rhs._node;
+		return _wrap._root != rhs._wrap._root || _parent._root != rhs._parent._root;
 	}
 
 	PUGI__FN xml_node& xml_named_node_iterator::operator*() const
 	{
-		assert(_node._root);
-		return _node;
+		assert(_wrap._root);
+		return _wrap;
 	}
 
 	PUGI__FN xml_node* xml_named_node_iterator::operator->() const
 	{
-		assert(_node._root);
-		return const_cast<xml_node*>(&_node); // BCC32 workaround
+		assert(_wrap._root);
+		return const_cast<xml_node*>(&_wrap); // BCC32 workaround
 	}
 
 	PUGI__FN const xml_named_node_iterator& xml_named_node_iterator::operator++()
 	{
-		assert(_node._root);
-		_node = _node.next_sibling(_name);
+		assert(_wrap._root);
+		_wrap = _wrap.next_sibling(_name);
 		return *this;
 	}
 
@@ -5173,6 +5177,28 @@ namespace pugi
 		return temp;
 	}
 
+	PUGI__FN const xml_named_node_iterator& xml_named_node_iterator::operator--()
+	{
+		if (_wrap._root)
+			_wrap = _wrap.previous_sibling(_name);
+		else
+		{
+			_wrap = _parent.last_child();
+
+			if (!impl::strequal(_wrap.name(), _name))
+				_wrap = _wrap.previous_sibling(_name);
+		}
+
+		return *this;
+	}
+
+	PUGI__FN xml_named_node_iterator xml_named_node_iterator::operator--(int)
+	{
+		xml_named_node_iterator temp = *this;
+		--*this;
+		return temp;
+	}
+
 	PUGI__FN xml_parse_result::xml_parse_result(): status(status_internal_error), offset(0), encoding(encoding_auto)
 	{
 	}
@@ -5481,9 +5507,9 @@ namespace std
 		return std::bidirectional_iterator_tag();
 	}
 
-	PUGI__FN std::forward_iterator_tag _Iter_cat(const pugi::xml_named_node_iterator&)
+	PUGI__FN std::bidirectional_iterator_tag _Iter_cat(const pugi::xml_named_node_iterator&)
 	{
-		return std::forward_iterator_tag();
+		return std::bidirectional_iterator_tag();
 	}
 }
 #endif
@@ -5502,9 +5528,9 @@ namespace std
 		return std::bidirectional_iterator_tag();
 	}
 
-	PUGI__FN std::forward_iterator_tag __iterator_category(const pugi::xml_named_node_iterator&)
+	PUGI__FN std::bidirectional_iterator_tag __iterator_category(const pugi::xml_named_node_iterator&)
 	{
-		return std::forward_iterator_tag();
+		return std::bidirectional_iterator_tag();
 	}
 }
 #endif
diff --git a/src/pugixml.hpp b/src/pugixml.hpp
index f14c710..db1507a 100644
--- a/src/pugixml.hpp
+++ b/src/pugixml.hpp
@@ -753,6 +753,8 @@ namespace pugi
 	// Named node range helper
 	class PUGIXML_CLASS xml_named_node_iterator
 	{
+		friend class xml_node;
+
 	public:
 		// Iterator traits
 		typedef ptrdiff_t difference_type;
@@ -761,7 +763,7 @@ namespace pugi
 		typedef xml_node& reference;
 
 	#ifndef PUGIXML_NO_STL
-		typedef std::forward_iterator_tag iterator_category;
+		typedef std::bidirectional_iterator_tag iterator_category;
 	#endif
 
 		// Default constructor
@@ -780,9 +782,15 @@ namespace pugi
 		const xml_named_node_iterator& operator++();
 		xml_named_node_iterator operator++(int);
 
+		const xml_named_node_iterator& operator--();
+		xml_named_node_iterator operator--(int);
+
 	private:
-		mutable xml_node _node;
+		mutable xml_node _wrap;
+		xml_node _parent;
 		const char_t* _name;
+
+		xml_named_node_iterator(xml_node_struct* ref, xml_node_struct* parent, const char_t* name);
 	};
 
 	// Abstract tree walker class (see xml_node::traverse)
@@ -1234,7 +1242,7 @@ namespace std
 	// Workarounds for (non-standard) iterator category detection for older versions (MSVC7/IC8 and earlier)
 	std::bidirectional_iterator_tag PUGIXML_FUNCTION _Iter_cat(const pugi::xml_node_iterator&);
 	std::bidirectional_iterator_tag PUGIXML_FUNCTION _Iter_cat(const pugi::xml_attribute_iterator&);
-	std::forward_iterator_tag PUGIXML_FUNCTION _Iter_cat(const pugi::xml_named_node_iterator&);
+	std::bidirectional_iterator_tag PUGIXML_FUNCTION _Iter_cat(const pugi::xml_named_node_iterator&);
 }
 #endif
 
@@ -1244,7 +1252,7 @@ namespace std
 	// Workarounds for (non-standard) iterator category detection
 	std::bidirectional_iterator_tag PUGIXML_FUNCTION __iterator_category(const pugi::xml_node_iterator&);
 	std::bidirectional_iterator_tag PUGIXML_FUNCTION __iterator_category(const pugi::xml_attribute_iterator&);
-	std::forward_iterator_tag PUGIXML_FUNCTION __iterator_category(const pugi::xml_named_node_iterator&);
+	std::bidirectional_iterator_tag PUGIXML_FUNCTION __iterator_category(const pugi::xml_named_node_iterator&);
 }
 #endif
 
diff --git a/tests/test_dom_traverse.cpp b/tests/test_dom_traverse.cpp
index 1668174..9c7c9ec 100644
--- a/tests/test_dom_traverse.cpp
+++ b/tests/test_dom_traverse.cpp
@@ -22,12 +22,6 @@ template <typename I> static I move_iter(I base, int n)
 	else while (n++) --base;
 	return base;
 }
-
-static xml_named_node_iterator move_iter(xml_named_node_iterator base, int n)
-{
-	while (n--) ++base;
-	return base;
-}
 #else
 template <typename I> static I move_iter(I base, int n)
 {
@@ -919,36 +913,51 @@ TEST_XML(dom_hash_value, "<node attr='value'>value</node>")
     CHECK(attr_copy.hash_value() == attr.hash_value());
 }
 
-TEST_XML(dom_node_named_iterator, "<node><node1><child/></node1><node2><child/><child/></node2><node3/></node>")
+TEST_XML(dom_node_named_iterator, "<node><node1><child/></node1><node2><child/><child/></node2><node3/><node4><child/><x/></node4></node>")
 {
 	xml_node node1 = doc.child(STR("node")).child(STR("node1"));
 	xml_node node2 = doc.child(STR("node")).child(STR("node2"));
 	xml_node node3 = doc.child(STR("node")).child(STR("node3"));
+	xml_node node4 = doc.child(STR("node")).child(STR("node4"));
 
 	CHECK(xml_named_node_iterator(xml_node(), STR("child")) == xml_named_node_iterator());
 
-    xml_named_node_iterator it1(node1.child(STR("child")), STR("child"));
-	CHECK(move_iter(it1, 1) == xml_named_node_iterator());
-	CHECK(*it1 == node1.child(STR("child")));
-	CHECK_STRING(it1->name(), STR("child"));
+	xml_object_range<xml_named_node_iterator> r1 = node1.children(STR("child"));
+	xml_object_range<xml_named_node_iterator> r2 = node2.children(STR("child"));
+	xml_object_range<xml_named_node_iterator> r3 = node3.children(STR("child"));
+	xml_object_range<xml_named_node_iterator> r4 = node4.children(STR("child"));
 
-    xml_named_node_iterator it2(node2.child(STR("child")), STR("child"));
-	CHECK(move_iter(it2, 1) != xml_named_node_iterator());
-	CHECK(move_iter(it2, 2) == xml_named_node_iterator());
-    CHECK(*it2 == node2.first_child());
-    CHECK(*move_iter(it2, 1) == node2.last_child());
+	CHECK(r1.begin() != r1.end());
+	CHECK(*r1.begin() == node1.first_child());
+	CHECK(r1.begin() == move_iter(r1.end(), -1));
+	CHECK(move_iter(r1.begin(), 1) == r1.end());
 
-    xml_named_node_iterator it3(node3.child(STR("child")), STR("child"));
-	CHECK(it3 == xml_named_node_iterator());
+	CHECK(r2.begin() != r2.end());
+	CHECK(*r2.begin() == node2.first_child());
+	CHECK(*move_iter(r2.begin(), 1) == node2.last_child());
+	CHECK(r2.begin() == move_iter(r2.end(), -2));
+	CHECK(move_iter(r2.begin(), 1) == move_iter(r2.end(), -1));
+	CHECK(move_iter(r2.begin(), 2) == r2.end());
 
-	xml_named_node_iterator it = xml_named_node_iterator(node1.child(STR("child")), STR("child"));
+	CHECK(r3.begin() == r3.end());
+	CHECK(!(r3.begin() != r3.end()));
+
+	CHECK(r4.begin() != r4.end());
+	CHECK(*r4.begin() == node4.first_child());
+	CHECK(r4.begin() == move_iter(r4.end(), -1));
+	CHECK(move_iter(r4.begin(), 1) == r4.end());
+
+	xml_named_node_iterator it = r1.begin();
 	xml_named_node_iterator itt = it;
 
 	CHECK(itt == it);
 
 	CHECK(itt++ == it);
-	CHECK(itt == xml_named_node_iterator());
+	CHECK(itt == r1.end());
 
 	CHECK(itt != it);
 	CHECK(itt == ++it);
+
+	CHECK(itt-- == r1.end());
+	CHECK(itt == r1.begin());
 }