-void List_Create(llist_t *list);
-void List_Add(llist_t *node, llist_t *start);
-void List_Add_Tail(llist_t *node, llist_t *start);
-void List_Delete(llist_t *node);
-void List_Delete_Init(llist_t *node);
-void List_Replace(llist_t *old, llist_t *_new);
-void List_Replace_Init(llist_t *old, llist_t *_new);
-void List_Swap(llist_t *node1, llist_t *node2);
-void List_Move(llist_t *list, llist_t *start);
-void List_Move_Tail(llist_t *list, llist_t *start);
-void List_Bulk_Move_Tail(llist_t *start, llist_t *first, llist_t *last);
-void List_Rotate_Left(llist_t *head);
-void List_Rotate_To_Front(llist_t *list, llist_t *head);
-void List_Splice(const llist_t *list, llist_t *head);
-void List_Splice_Tail(const llist_t *list, llist_t *head);
-qbool List_Is_First(llist_t *list, llist_t *start);
-qbool List_Is_Last(llist_t *list, llist_t *start);
-qbool List_Is_Empty(const llist_t *list);
+static inline qbool List_Is_Empty(const llist_t *list)
+{
+ return list->next == list;
+}
+
+/*
+ * Creates a new linked list. Initializes the head to point to itself.
+ * If it's a list header, the result is an empty list.
+ */
+static inline void List_Create(llist_t *list)
+{
+ list->next = list->prev = list;
+}
+
+/*
+ * Insert a node between two known nodes.
+ *
+ * Only use when prev and next are known.
+ */
+static inline void __List_Add(llist_t *node, llist_t *prev, llist_t *next)
+{
+ next->prev = node;
+ node->next = next;
+ node->prev = prev;
+ prev->next = node;
+}
+
+/*
+ * Insert a node immediately after head.
+ */
+static inline void List_Add(llist_t *node, llist_t *head)
+{
+ __List_Add(node, head, head->next);
+}
+
+/*
+ * Insert a node immediately before head.
+ */
+static inline void List_Add_Tail(llist_t *node, llist_t *head)
+{
+ __List_Add(node, head->prev, head);
+}
+
+/*
+ * Bridge prev and next together, when removing the parent of them.
+ */
+static inline void __List_Delete(llist_t *prev, llist_t *next)
+{
+ next->prev = prev;
+ prev->next = next;
+}
+
+/*
+ * Redundant?
+ */
+static inline void __List_Delete_Node(llist_t *node)
+{
+ __List_Delete(node->prev, node->next);
+}
+
+/*
+ * Removes a node from its list. Sets its pointers to NULL.
+ */
+static inline void List_Delete(llist_t *node)
+{
+ __List_Delete_Node(node);
+ node->next = node->prev = NULL;
+}
+
+/*
+ * Removes a node from its list. Reinitialize it.
+ */
+static inline void List_Delete_Init(llist_t *node)
+{
+ __List_Delete_Node(node);
+ node->next = node->prev = node;
+}
+
+/*
+ * Replace old with new. Old is overwritten if empty.
+ */
+static inline void List_Replace(llist_t *old, llist_t *_new)
+{
+ _new->next = old->next;
+ _new->next->prev = _new;
+ _new->prev = old->prev;
+ _new->prev->next = _new;
+ old->next = old->prev = old;
+}
+
+/*
+ * Replace old with new. Initialize old.
+ * Old is overwritten if empty.
+ */
+static inline void List_Replace_Init(llist_t *old, llist_t *_new)
+{
+ List_Replace(old, _new);
+ List_Create(old);
+}
+
+/*
+ * Swap node1 with node2 in place.
+ */
+static inline void List_Swap(llist_t *node1, llist_t *node2)
+{
+ llist_t *pos = node2->prev;
+ List_Delete_Init(node2);
+ List_Replace(node1, node2);
+ if(pos == node1)
+ pos = node2;
+ List_Add(node1, pos);
+}
+
+/*
+ * Delete list from its... list, then insert after head.
+ */
+static inline void List_Move(llist_t *list, llist_t *head)
+{
+ __List_Delete_Node(list);
+ List_Add(list, head);
+}
+
+/*
+ * Delete list from its... list, then insert before head.
+ */
+static inline void List_Move_Tail(llist_t *list, llist_t *head)
+{
+ __List_Delete_Node(list);
+ List_Add_Tail(list, head);
+}
+
+/*
+ * Move the first node of a range of nodes immediately after head.
+ * All three parameters must belong to the same list.
+ */
+
+static inline void List_Bulk_Move_Tail(llist_t *head, llist_t *first, llist_t *last)
+{
+ first->prev->next = last->next;
+ last->next->prev = first->prev;
+
+ head->prev->next = first;
+ first->prev = head->prev;
+
+ last->next = head;
+ head->prev = last;
+}
+
+/*
+ * Shift the head to the right (like rotating a wheel counterclockwise).
+ * The node immediately to the right becomes the new head.
+ */
+static inline void List_Rotate_Left(llist_t *head)
+{
+ llist_t *first;
+
+ if (!List_Is_Empty(head))
+ {
+ first = head->next;
+ List_Move_Tail(first, head);
+ }
+}
+
+/*
+ * Make list the new head.
+ */
+static inline void List_Rotate_To_Front(llist_t *list, llist_t *head)
+{
+ List_Move_Tail(head, list);
+}
+
+/*
+ * Concatenate two lists. The head of list will be discarded.
+ */
+static inline void __List_Splice(const llist_t *list, llist_t *prev, llist_t *next)
+{
+ llist_t *first = list->next;
+ llist_t *last = list->prev;
+
+ first->prev = prev;
+ prev->next = first;
+
+ last->next = next;
+ next->prev = last;
+}
+
+/*
+ * Concatenate two lists. The first node of list will be inserted after head.
+ */
+static inline void List_Splice(const llist_t *list, llist_t *head)
+{
+ if(!List_Is_Empty(list))
+ __List_Splice(list, head, head->next);
+}
+
+/*
+ * Concatenate two lists. The tail of list will be inserted before head.
+ */
+static inline void List_Splice_Tail(const llist_t *list, llist_t *head)
+{
+ if (!List_Is_Empty(list))
+ __List_Splice(list, head->prev, head);
+}
+
+static inline qbool List_Is_First(llist_t *list, llist_t *start)
+{
+ return list->prev == start;
+}
+
+static inline qbool List_Is_Last(llist_t *list, llist_t *start)
+{
+ return list->next == start;
+}