Mercurial > hg > ucx / file diff

--- a/src/cx/linked_list.h	Fri Oct 10 12:26:43 2025 +0200
+++ b/src/cx/linked_list.h	Fri Oct 10 17:24:19 2025 +0200
@@ -387,7 +387,7 @@
 
 /**
  * Inserts a chain of nodes into a sorted linked list.
- * The chain must not be part of any list already.
+ * The chain must not be part of any list yet.
  *
  * If either the list starting with the node pointed to by @p begin or the list
  * starting with @p insert_begin is not sorted, the behavior is undefined.
@@ -416,6 +416,64 @@
 );
 
 /**
+ * Inserts a node into a sorted linked list if no other node with the same value already exists.
+ * The new node must not be part of any list yet.
+ *
+ * If the list starting with the node pointed to by @p begin is not sorted
+ * already, the behavior is undefined.
+ *
+ * @param begin a pointer to the beginning node pointer (required)
+ * @param end a pointer to the end node pointer (if your list has one)
+ * @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
+ * @param loc_next the location of a @c next pointer within your node struct (required)
+ * @param new_node a pointer to the node that shall be inserted
+ * @param cmp_func a compare function that will receive the node pointers
+ * @retval zero when the node was inserted
+ * @retval non-zero when a node with the same value already exists
+ */
+cx_attr_nonnull_arg(1, 5, 6)
+cx_attr_export
+int cx_linked_list_insert_unique(
+        void **begin,
+        void **end,
+        ptrdiff_t loc_prev,
+        ptrdiff_t loc_next,
+        void *new_node,
+        cx_compare_func cmp_func
+);
+
+/**
+ * Inserts a chain of nodes into a sorted linked list, avoiding duplicates.
+ * The chain must not be part of any list yet.
+ *
+ * If either the list starting with the node pointed to by @p begin or the list
+ * starting with @p insert_begin is not sorted, the behavior is undefined.
+ * Also, the chain to be inserted must not contain duplicates within itself.
+ *
+ * @attention In contrast to cx_linked_list_insert_sorted(), not all nodes of the
+ * chain might be added. This function returns a new chain consisting of all the duplicates.
+ *
+ * @param begin a pointer to the beginning node pointer (required)
+ * @param end a pointer to the end node pointer (if your list has one)
+ * @param loc_prev the location of a @c prev pointer within your node struct (negative if your struct does not have one)
+ * @param loc_next the location of a @c next pointer within your node struct (required)
+ * @param insert_begin a pointer to the first node of the chain that shall be inserted
+ * @param cmp_func a compare function that will receive the node pointers
+ * @return a pointer to a new chain with all duplicates which were not inserted (or @c NULL when there were no duplicates)
+ */
+cx_attr_nonnull_arg(1, 5, 6)
+cx_attr_nodiscard
+cx_attr_export
+void *cx_linked_list_insert_unique_chain(
+        void **begin,
+        void **end,
+        ptrdiff_t loc_prev,
+        ptrdiff_t loc_next,
+        void *insert_begin,
+        cx_compare_func cmp_func
+);
+
+/**
  * Removes a chain of nodes from the linked list.
  *
  * If one of the nodes to remove is the beginning (resp. end) node of the list and if @p begin (resp. @p end)