libBLOC

diff --git a/include/BLOC/iterator.h b/include/BLOC/iterator.h
new file mode 100644
index 0000000..62bdd6b
--- /dev/null
+++ b/include/BLOC/iterator.h
@@ -0,0 +1,51 @@
+/*
+ * 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/>.
+ */
+
+#ifndef _BLOC_ITERATOR_H
+#define _BLOC_ITERATOR_H
+
+typedef struct Iterator Iterator;
+
+/* Structure for an Iterable object header */
+struct Iterable {
+	unsigned int magic;
+	struct IterableEntry *start, *end;
+	unsigned int entries;
+};
+
+/* Structure for an Iterable object entry header */
+struct IterableEntry {
+	struct IterableEntry *prev, *next;
+	void *obj;
+};
+
+void iterable_init(struct Iterable *header);
+
+Iterator *iterator_create(void *iterable);
+void *iterator_first(Iterator *iter);
+void *iterator_last(Iterator *iter);
+void *iterator_next(Iterator *iter);
+void *iterator_prev(Iterator *iter);
+
+#define foreach(l,i) for (Iterator *(__l_##i) = iterator_create((void *) (l)); \
+                          (__l_##i); obj_put(__l_##i), (__l_##i) = NULL) \
+                     for ((i) = iterator_first(__l_##i); (i); \
+                          (i) = iterator_next(__l_##i))
+
+#endif