tree: copy-tree-iter function.

* lib.c (copy): Handle tree_iter_s via copy_tree_iter.

* tree.c (copy_tree_iter): New function.
(tree_init): copy-tree-iter intrinsic registered.

* tree.h (copy_tree_iter): Declared.

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

* txr.1: Documented.

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

1 files changed, 2 insertions, 1 deletions

diff --git a/tree.h b/tree.h
index 690cd91b..72ee43db 100644
--- a/tree.h
+++ b/tree.h
@@ -25,7 +25,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-extern val tree_s, tree_fun_whitelist_s;
+extern val tree_s, tree_iter_s, tree_fun_whitelist_s;
 
 #define tree_fun_whitelist (deref(lookup_var_l(nil, tree_fun_whitelist_s)))
 
@@ -50,6 +50,7 @@ val tree_delete_node(val tree, val key);
 val tree_delete(val tree, val key);
 val tree_begin(val tree);
 val tree_begin_at(val tree, val lowkey);
+val copy_tree_iter(val iter);
 val tree_reset(val iter, val tree);
 val tree_reset_at(val iter, val tree, val lowkey);
 val tree_next(val iter);