Import quark sources

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 58 insertions, 0 deletions

diff --git a/include/list.h b/include/list.h
new file mode 100644
index 0000000..0364f7c
--- /dev/null
+++ b/include/list.h
@@ -0,0 +1,58 @@
+/*
+ * Tiny doubly-linked list implementation.
+ * Copyright (c) 2023-2024, Quinn Stephens and the OSMORA team.
+ * Provided under the BSD 3-Clause license.
+ */
+
+#ifndef _LIST_H
+#define _LIST_H
+
+#include <stddef.h>
+
+struct list_entry {
+    struct list_entry *prev;
+    struct list_entry *next;
+};
+
+struct list {
+    struct list_entry *tail;
+    struct list_entry *head;
+    size_t length;
+};
+
+static inline void
+list_remove(struct list_entry *entry)
+{
+    entry->prev->next = entry->next;
+    entry->next->prev = entry->prev;
+}
+
+static inline void
+list_append(struct list *list, struct list_entry *entry)
+{
+    entry->prev = list->tail;
+    entry->next = (struct list_entry*)list;
+    entry->prev->next = entry;
+    list->tail = entry;
+    list->length++;
+}
+
+static inline void
+list_prepend(struct list *list, struct list_entry *entry)
+{
+    entry->next = list->head;
+    entry->prev = (struct list_entry*)list;
+    entry->next->prev = entry;
+    list->head = entry;
+    list->length++;
+}
+
+static inline void
+list_init(struct list *list)
+{
+    list->tail = (struct list_entry*)list;
+    list->head = (struct list_entry*)list;
+    list->length = 0;
+}
+
+#endif /* !_LIST_H */