Move the linkedlist to libmisc

1 files changed, 57 insertions, 0 deletions

diff --git a/libmisc/include/libmisc/linkedlist.h b/libmisc/include/libmisc/linkedlist.h
new file mode 100644
index 0000000..045a468
--- /dev/null
+++ b/libmisc/include/libmisc/linkedlist.h
@@ -0,0 +1,57 @@
+/* libmisc/linkedlist.h - Singly- and doubly- linked lists
+ *
+ * Copyright (C) 2024-2025  Luke T. Shumaker <lukeshu@lukeshu.com>
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+#ifndef _LIBMISC_LINKEDLIST_H_
+#define _LIBMISC_LINKEDLIST_H_
+
+#include <libmisc/assert.h>
+
+/* singly linked list *********************************************************/
+
+typedef struct _lm_sll_node {
+	struct _lm_sll_node *rear;
+} lm_sll_node;
+
+typedef struct {
+	lm_sll_node *front, *rear;
+} lm_sll_root;
+
+#define lm_sll_node_cast(node_typ, node_ptr)                                    \
+	({                                                                      \
+		static_assert(_Generic(node_ptr, lm_sll_node *: 1, default: 0), \
+		              "typeof("#node_ptr") != lm_sll_node *");          \
+		assert(node_ptr);                                               \
+		static_assert(offsetof(node_typ, lm_sll_node) == 0);            \
+		((node_typ*)(node_ptr));                                        \
+	})
+
+void lm_sll_push_to_rear(lm_sll_root *root, lm_sll_node *node);
+void lm_sll_pop_from_front(lm_sll_root *root);
+
+/* doubly linked list *********************************************************/
+
+typedef struct _lm_dll_node {
+	struct _lm_dll_node *front, *rear;
+} lm_dll_node;
+
+typedef struct {
+	lm_dll_node *front, *rear;
+} lm_dll_root;
+
+#define lm_dll_node_cast(node_typ, node_ptr)                                    \
+	({                                                                      \
+		static_assert(_Generic(node_ptr, lm_dll_node *: 1, default: 0), \
+		              "typeof("#node_ptr") != lm_dll_node *");          \
+		assert(node_ptr);                                               \
+		static_assert(offsetof(node_typ, lm_dll_node) == 0);            \
+		((node_typ*)(node_ptr));                                        \
+	})
+
+void lm_dll_push_to_rear(lm_dll_root *root, lm_dll_node *node);
+void lm_dll_remove(lm_dll_root *root, lm_dll_node *node);
+void lm_dll_pop_from_front(lm_dll_root *root);
+
+#endif /* _LIBMISC_LINKEDLIST_H_ */