1 files changed, 36 insertions, 17 deletions

diff --git a/zix/tree.h b/zix/tree.h
index ccaf06e..cdcec10 100644
--- a/zix/tree.h
+++ b/zix/tree.h
@@ -38,14 +38,9 @@ extern "C" {
 typedef struct ZixTreeImpl ZixTree;
 
 /**
-   A node in a @ref ZixTree.
-*/
-typedef struct ZixTreeNodeImpl ZixTreeNode;
-
-/**
    An iterator over a @ref ZixTree.
 */
-typedef ZixTreeNode* ZixTreeIter;
+typedef struct ZixTreeNodeImpl ZixTreeIter;
 
 /**
    Create a new (empty) tree.
@@ -63,50 +58,74 @@ zix_tree_free(ZixTree* t);
    Insert the element @a e into @a t and point @a ti at the new element.
 */
 ZixStatus
-zix_tree_insert(ZixTree* t, const void* e, ZixTreeIter* ti);
+zix_tree_insert(ZixTree* t, void* e, ZixTreeIter** ti);
 
 /**
    Remove the item pointed at by @a ti from @a t.
 */
 ZixStatus
-zix_tree_remove(ZixTree* t, ZixTreeIter ti);
+zix_tree_remove(ZixTree* t, ZixTreeIter* ti);
 
 /**
-   Set @a ti to be the largest element <= @a e in @a t.
+   Set @a ti to an element equal to @a e in @a t.
    If no such item exists, @a ti is set to NULL.
 */
 ZixStatus
-zix_tree_find(const ZixTree* t, const void* e, ZixTreeIter* ti);
+zix_tree_find(const ZixTree* t, const void* e, ZixTreeIter** ti);
 
 /**
    Return the data associated with the given tree item.
 */
-const void*
-zix_tree_get_data(ZixTreeIter ti);
+void*
+zix_tree_get(ZixTreeIter* ti);
 
 /**
    Return an iterator to the first (smallest) element in @a t.
 */
-ZixTreeIter
+ZixTreeIter*
 zix_tree_begin(ZixTree* t);
 
 /**
    Return an iterator the the element one past the last element in @a t.
 */
-ZixTreeIter
+ZixTreeIter*
 zix_tree_end(ZixTree* t);
 
 /**
    Return true iff @a i is an iterator to the end of its tree.
 */
 bool
-zix_tree_iter_is_end(ZixTreeIter i);
+zix_tree_iter_is_end(ZixTreeIter* i);
+
+/**
+   Return an iterator to the last (largest) element in @a t.
+*/
+ZixTreeIter*
+zix_tree_rbegin(ZixTree* t);
+
+/**
+   Return an iterator the the element one before the first element in @a t.
+*/
+ZixTreeIter*
+zix_tree_rend(ZixTree* t);
+
+/**
+   Return true iff @a i is an iterator to the reverse end of its tree.
+*/
+bool
+zix_tree_iter_is_rend(ZixTreeIter* i);
 
 /**
    Return an iterator that points to the element one past @a i.
 */
-ZixTreeIter
-zix_tree_iter_next(ZixTreeIter i);
+ZixTreeIter*
+zix_tree_iter_next(ZixTreeIter* i);
+
+/**
+   Return an iterator that points to the element one before @a i.
+*/
+ZixTreeIter*
+zix_tree_iter_prev(ZixTreeIter* i);
 
 /**
    @}