tree: new make_similar_tree unction.

* tree.c (make_similar_tree): New function.
(tree_init): Register make-similar-tree intrinsic

* tree.h (make_similar_tree): Declared.

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

* txr.1: Documented.

1 files changed, 13 insertions, 0 deletions

diff --git a/tree.c b/tree.c
index 9a7044f0..47bbe8d6 100644
--- a/tree.c
+++ b/tree.c
@@ -711,6 +711,18 @@ val copy_search_tree(val tree)
   return ntree;
 }
 
+val make_similar_tree(val tree)
+{
+  val self = lit("make-similar-tree");
+  struct tree *ntr = coerce(struct tree *, malloc(sizeof *ntr));
+  struct tree *otr = coerce(struct tree *, cobj_handle(self, tree, tree_s));
+  val ntree = cobj(coerce(mem_t *, ntr), tree_s, &tree_ops);
+  *ntr = *otr;
+  ntr->root = nil;
+  ntr->size = ntr->max_size = 0;
+  return ntree;
+}
+
 val treep(val obj)
 {
   return tnil(type(obj) == COBJ && obj->co.cls == tree_s);
@@ -834,6 +846,7 @@ void tree_init(void)
   reg_fun(tree_s, func_n4o(tree, 0));
   reg_fun(tree_construct_s, func_n2(tree_construct));
   reg_fun(intern(lit("copy-search-tree"), user_package), func_n1(copy_search_tree));
+  reg_fun(intern(lit("make-similar-tree"), user_package), func_n1(make_similar_tree));
   reg_fun(intern(lit("treep"), user_package), func_n1(treep));
   reg_fun(intern(lit("tree-insert-node"), user_package), func_n2(tree_insert_node));
   reg_fun(intern(lit("tree-insert"), user_package), func_n2(tree_insert));