tree: new functions for priority queue operation.

* tree.c (tree_min_node, tree_min, tree_del_min_node,
tree_del_min): New functions.
(tree_init): tree-min-node, tree-min, tree-del-min-node,
tree-del-min: New intrinsics registered.

* tree.h (tree_min_node, tree_min, tree_del_min_node,
tree_del_min): Declared.

* txr.1: Documented.

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

* stdlib/doc-syms.tl: Updated.

1 files changed, 30 insertions, 0 deletions

diff --git a/tests/010/tree.tl b/tests/010/tree.tl
index 79bab793..56d04fa9 100644
--- a/tests/010/tree.tl
+++ b/tests/010/tree.tl
@@ -226,3 +226,33 @@
   (test (tree-count tr) 2)
   (tree-insert tr 1 t)
   (test (tree-count tr) 3))
+
+(mtest
+  (tree-min-node (tree)) nil
+  (tree-min-node (tree '(1))) #N(1 nil nil)
+  (tree-min-node (tree '(1 2 3))) #N(1 nil nil))
+
+(mtest
+  (tree-min (tree)) nil
+  (tree-min (tree '(1))) 1
+  (tree-min (tree '(1 2 3))) 1)
+
+(let ((tr (tree '(1 2 3 4 5 6 7 8 9 10))))
+  (mtest
+    (tree-count tr) 10
+    (tree-del-min tr) 1
+    (tree-del-min tr) 2
+    (tree-del-min tr) 3
+    (tree-count tr) 7
+    (tree-del-min tr) 4
+    (tree-count tr) 6
+    (tree-del-min tr) 5
+    (tree-del-min tr) 6
+    (tree-del-min tr) 7
+    (tree-del-min tr) 8
+    (tree-count tr) 2
+    (tree-del-min tr) 9
+    (tree-count tr) 1
+    (tree-del-min tr) 10
+    (tree-count tr) 0
+    (tree-del-min tr) nil))