tree: new functions for reseting iterator.

* tree.c (tree_reset, tree_reset_at): New functions.
(tree_init): tree-reset and tree-reset-at intrinsics
registered.

* tree.h (tree_reset, tree_reset_at): Declared.

* tests/010/tree.tl: New tests.

* txr.1: Documented.

* share/txr/stdlib/doc-syms.tl: Updated.

1 files changed, 15 insertions, 0 deletions

diff --git a/tests/010/tree.tl b/tests/010/tree.tl
index 83b3172c..fde11300 100644
--- a/tests/010/tree.tl
+++ b/tests/010/tree.tl
@@ -40,6 +40,14 @@
                 (add (key n))))
        (range 0 19))
 
+(vtest (build (for* ((j (tree-begin tr))
+                     (i (progn (tree-next j) (tree-next j) (tree-reset j tr)))
+                     (n (tree-next i)))
+                    (n)
+                    ((set n (tree-next i)))
+                (add (key n))))
+       (range 0 19))
+
 (defvarl trc (copy-search-tree tr))
 
 (vtest trc tr)
@@ -71,6 +79,13 @@
                 (add (key n))))
        (range 8 19))
 
+(vtest (build (for* ((i (tree-reset-at (tree-begin #T(())) tr 8))
+                     (n (tree-next i)))
+                    (n)
+                    ((set n (tree-next i)))
+                (add (key n))))
+       (range 8 19))
+
 (test (tree-next (tree-begin-at tr 20)) nil)
 
 (test (tree-next (tree-begin-at #T(()) 0)) nil)