libBLOC

diff --git a/tree/tree.c b/tree/tree.c
new file mode 100644
index 0000000..1bffd72
--- /dev/null
+++ b/tree/tree.c
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2023 Barry
+ *
+ * This file is part of Barry's Little Objects in C Library (libBLOC).
+ *
+ * libBLOC is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libBLOC is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTIBILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * libBLOC.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/*
+ * This file implements object Trees.  Object Trees work similarly to lists
+ * except trees store ordered data and are organised such that inserting,
+ * removing, and searching are more efficient.  Trees can also be created with
+ * a specific Object Type, and will only accept objects of that type.  If no
+ * type is specified, the tree can accept any object.
+ */
+
+#include <BLOC/object.h>
+#include <BLOC/tree.h>
+#include "../assert.h"
+#include "../object.h"
+#include "tree.h"
+
+static void _tree_new(void *);
+static void _tree_delete(void *);
+
+/* Tree object type */
+struct ObjectType treeType = {
+	.name = "Tree",
+	.size = sizeof(Tree),
+	.new = _tree_new,
+	.delete = _tree_delete,
+};
+
+/* Create a Tree object */
+static void
+_tree_new(void *obj)
+{
+	Tree *tree = obj;
+	iterable_init(&tree->header);
+}
+
+/* Destroy a Tree object */
+static void
+_tree_delete(void *obj)
+{
+	Tree *tree = obj;
+	struct TreeNode *node, *next;
+	for (node = (void *) tree->header.start; node; node = next) {
+		next = (struct TreeNode *) node->header.next;
+		obj_put(node->header.obj);
+		free(node);
+	}
+}
+
+/* Count the number of nodes in a (sub-)tree recursively */
+unsigned int
+_tree_count(struct TreeNode *root)
+{
+	if (!root)
+		return 0;
+	unsigned int n = 0;
+	n += _tree_count(root->left);
+	n += _tree_count(root->right);
+	return n + 1;
+}
+
+/* Rotate an entire tree left */
+struct TreeNode *
+_tree_rotate_left(struct TreeNode *root)
+{
+	struct TreeNode *tmp = root->right;
+	root->right = tmp->left;
+	tmp->left = root;
+	return tmp;
+}
+
+/* Rotate an entire tree right */
+struct TreeNode *
+_tree_rotate_right(struct TreeNode *root)
+{
+	struct TreeNode *tmp = root->left;
+	root->left = tmp->right;
+	tmp->right = root;
+	return tmp;
+}
+
+/* Create an object tree */
+Tree *
+tree_create(struct ObjectType *type, int (*compare)(void *, void *))
+{
+	if (!compare)
+		return NULL;
+	Tree *tree = obj_new(&treeType);
+	tree->type = type;
+	tree->compare = compare;
+	return tree;
+}
+
+/* Count the nodes in a tree */
+unsigned int
+tree_count(Tree *tree)
+{
+	return tree->header.entries;
+}