diff --git a/tree_node.cpp b/tree_node.cpp
index d2ae1e070..678205491 100644
--- a/tree_node.cpp
+++ b/tree_node.cpp
@@ -2,6 +2,35 @@
 #include "tree_pool.h"
 #include "expression_node.h"
 
+TreeNode * TreeNode::parent() const {
+  int cursor = -1;
+  TreeNode * parentsHistory[TreePool::MaxNumberOfNodes];
+  int numberOfChildrenHistory[TreePool::MaxNumberOfNodes];
+  int childrenVisitedCountHistory[TreePool::MaxNumberOfNodes];
+  for (TreeNode * node : TreePool::sharedPool()->allNodes()) {
+    if (node->identifier() == m_identifier) {
+      printf("Parent of %d is %d\n", m_identifier, cursor >= 0 ? parentsHistory[cursor]->identifier() : -1);
+      return cursor >= 0 ? parentsHistory[cursor] : nullptr;
+    }
+    if (cursor >= 0) {
+      childrenVisitedCountHistory[cursor] = childrenVisitedCountHistory[cursor]+1;
+    }
+    int nodeChildrenCount = node->numberOfChildren();
+    if (nodeChildrenCount > 0) {
+      cursor++;
+      parentsHistory[cursor] = node;
+      numberOfChildrenHistory[cursor] = nodeChildrenCount;
+      childrenVisitedCountHistory[cursor] = 0;
+    } else {
+      if (cursor >= 0 && (numberOfChildrenHistory[cursor] == childrenVisitedCountHistory[cursor])) {
+        cursor--;
+      }
+    }
+  }
+  assert(false);
+  return nullptr;
+}
+
 void TreeNode::release() {
   printf("Release %d(%p)\n", m_identifier, this);
   m_referenceCounter--;
diff --git a/tree_node.h b/tree_node.h
index 45b84b6d3..0a0cdfc9d 100644
--- a/tree_node.h
+++ b/tree_node.h
@@ -19,15 +19,13 @@ class TreeNode {
 //  friend class TreeReference<T>;
   friend class TreePool;
 public:
-  virtual ~TreeNode() {
-  }
-
+  virtual ~TreeNode() {}
   int indentifier() const { return m_identifier; }
 
-  // Iterators
+  TreeNode * parent() const;
 
   class Iterator {
-  public:
+    public:
     Iterator(TreeNode * node) : m_node(node) {}
     TreeNode * operator*() { return m_node; }
     bool operator!=(const Iterator& it) const { return (m_node != it.m_node); }
@@ -73,7 +71,6 @@ public:
 
   DepthFirst depthFirstChildren() { return DepthFirst(this); }
 
-
   int identifier() const { return m_identifier; }
 
 #if TREE_LOGGING
diff --git a/tree_pool.h b/tree_pool.h
index cb509aec5..b8b981a27 100644
--- a/tree_pool.h
+++ b/tree_pool.h
@@ -6,6 +6,7 @@
 #include <new>
 
 class TreePool {
+  friend class TreeNode;
 public:
   static TreePool * sharedPool();
 
@@ -88,17 +89,37 @@ public:
   void log();
 #endif
 
-private:
-  TreePool() : m_cursor(m_buffer) { }
-  static inline void insert(char * destination, char * source, size_t length);
+protected:
+  constexpr static int BufferSize = 256;
+  constexpr static int MaxNumberOfNodes = BufferSize/sizeof(TreeNode);
+
+  class AllPool {
+  public:
+    AllPool(TreeNode * node) : m_node(node) {}
+    class Iterator : public TreeNode::Iterator {
+    public:
+      using TreeNode::Iterator::Iterator;
+      Iterator & operator++() {
+        m_node = m_node->next();
+        return *this;
+      }
+    };
+    Iterator begin() const { return Iterator(m_node); }
+    Iterator end() const { return Iterator(TreePool::sharedPool()->last()); }
+  private:
+    TreeNode * m_node;
+  };
+  AllPool allNodes() { return AllPool(*(begin())); }
+
   TreeNode::DepthFirst::Iterator begin() const { return TreeNode::DepthFirst::Iterator(first()); }
   TreeNode::DepthFirst::Iterator end() const { return TreeNode::DepthFirst::Iterator(last()); }
 
-  char * m_cursor;
+private:
+  TreePool() : m_cursor(m_buffer) { }
+  static inline void insert(char * destination, char * source, size_t length);
 
-  constexpr static int BufferSize = 256;
+  char * m_cursor;
   char m_buffer[BufferSize];
-  constexpr static int MaxNumberOfNodes = BufferSize/sizeof(TreeNode);
   TreeNode * m_nodeForIdentifier[MaxNumberOfNodes];
 };