Move the linkedlist to libmisc

1 files changed, 62 insertions, 0 deletions

diff --git a/libmisc/linkedlist.c b/libmisc/linkedlist.c
new file mode 100644
index 0000000..5fe0977
--- /dev/null
+++ b/libmisc/linkedlist.c
@@ -0,0 +1,62 @@
+/* libmisc/linkedlist.c - Singly- and doubly- linked lists
+ *
+ * Copyright (C) 2024-2025  Luke T. Shumaker <lukeshu@lukeshu.com>
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+#include <stddef.h> /* for NULL */
+
+#include <libmisc/linkedlist.h>
+
+/* singly linked list *********************************************************/
+
+void lm_sll_push_to_rear(lm_sll_root *root, lm_sll_node *node) {
+	assert(root);
+	node->rear = NULL;
+	if (root->rear)
+		root->rear->rear = node;
+	else
+		root->front = node;
+	root->rear = node;
+}
+
+void lm_sll_pop_from_front(lm_sll_root *root) {
+	assert(root);
+	assert(root->front);
+	root->front = root->front->rear;
+	if (!root->front)
+		root->rear = NULL;
+}
+
+/* doubly linked list *********************************************************/
+
+void lm_dll_push_to_rear(lm_dll_root *root, lm_dll_node *node) {
+	assert(root);
+	assert(node);
+	node->front = root->rear;
+	node->rear = NULL;
+	if (root->rear)
+		root->rear->rear = node;
+	else
+		root->front = node;
+	root->rear = node;
+}
+
+void lm_dll_remove(lm_dll_root *root, lm_dll_node *node) {
+	assert(root);
+	assert(node);
+	if (node->front)
+		node->front->rear = node->rear;
+	else
+		root->front = node->rear;
+	if (node->rear)
+		node->rear->front = node->front;
+	else
+		root->rear = node->front;
+}
+
+void lm_dll_pop_from_front(lm_dll_root *root) {
+	assert(root);
+	assert(root->front);
+	lm_dll_remove(root, root->front);
+}