We should unify various forms of tree traversal in DOM

Source/core/dom/NodeTraversal.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef NodeTraversal_h
 #define NodeTraversal_h
 
 #include "core/dom/Node.h"
+#include "wtf/TreeNode.h"
 
 namespace WebCore {
 
 namespace NodeTraversal {
 
 // Does a pre-order traversal of the tree to find the next node after this one.
 // This uses the same order that tags appear in the source file. If the stayWithin
 // argument is non-null, the traversal will stop once the specified node is reached.
 // This can be used to restrict traversal to a particular sub-tree.
 Node* next(const Node&);
@@ skipping 21 matching lines @@
 Node* previousSkippingChildrenPostOrder(const Node&, const Node* stayWithin = 0);
 
 // Pre-order traversal including the pseudo-elements.
 Node* previousIncludingPseudo(const Node&, const Node* stayWithin = 0);
 Node* nextIncludingPseudo(const Node&, const Node* stayWithin = 0);
 Node* nextIncludingPseudoSkippingChildren(const Node&, const Node* stayWithin = 0);
 
 Node* nextAncestorSibling(const Node&);
 Node* nextAncestorSibling(const Node&, const Node* stayWithin);
 
-template <class NodeType>
-inline Node* traverseNextTemplate(NodeType& current)
-{
-    if (current.firstChild())
-        return current.firstChild();
-    if (current.nextSibling())
-        return current.nextSibling();
-    return nextAncestorSibling(current);
-}
-inline Node* next(const Node& current) { return traverseNextTemplate(current); }
-inline Node* next(const ContainerNode& current) { return traverseNextTemplate(current); }
+inline Node* next(const Node& current) { return traverseNext(current); }
+inline Node* next(const ContainerNode& current) { return traverseNext<Node>(current); }
 
-template <class NodeType>
-inline Node* traverseNextTemplate(NodeType& current, const Node* stayWithin)
-{
-    if (current.firstChild())
-        return current.firstChild();
-    if (current == stayWithin)
-        return 0;
-    if (current.nextSibling())
-        return current.nextSibling();
-    return nextAncestorSibling(current, stayWithin);
-}
-inline Node* next(const Node& current, const Node* stayWithin) { return traverseNextTemplate(current, stayWithin); }
-inline Node* next(const ContainerNode& current, const Node* stayWithin) { return traverseNextTemplate(current, stayWithin); }
+inline Node* next(const Node& current, const Node* stayWithin) { return traverseNext(current, stayWithin); }
+inline Node* next(const ContainerNode& current, const Node* stayWithin) { return traverseNext<Node>(current, stayWithin); }
 
-template <class NodeType>
-inline Node* traverseNextSkippingChildrenTemplate(NodeType& current)
-{
-    if (current.nextSibling())
-        return current.nextSibling();
-    return nextAncestorSibling(current);
-}
-inline Node* nextSkippingChildren(const Node& current) { return traverseNextSkippingChildrenTemplate(current); }
-inline Node* nextSkippingChildren(const ContainerNode& current) { return traverseNextSkippingChildrenTemplate(current); }
+inline Node* nextSkippingChildren(const Node& current) { return traverseNextSkippingChildren(current); }
+inline Node* nextSkippingChildren(const ContainerNode& current) { return traverseNextSkippingChildren<Node>(current); }
 
-template <class NodeType>
-inline Node* traverseNextSkippingChildrenTemplate(NodeType& current, const Node* stayWithin)
-{
-    if (current == stayWithin)
-        return 0;
-    if (current.nextSibling())
-        return current.nextSibling();
-    return nextAncestorSibling(current, stayWithin);
-}
-inline Node* nextSkippingChildren(const Node& current, const Node* stayWithin) { return traverseNextSkippingChildrenTemplate(current, stayWithin); }
-inline Node* nextSkippingChildren(const ContainerNode& current, const Node* stayWithin) { return traverseNextSkippingChildrenTemplate(current, stayWithin); }
+inline Node* nextSkippingChildren(const Node& current, const Node* stayWithin) { return traverseNextSkippingChildren(current, stayWithin); }
+inline Node* nextSkippingChildren(const ContainerNode& current, const Node* stayWithin) { return traverseNextSkippingChildren<Node>(current, stayWithin); }
 
 }
 
 }
 
 #endif