Add a value to the list

src/ordinary.c

@@ -17,3 +17,42 @@ void ordinary_list_del(struct ordinary_list *list) {
     at = next;
   }
 }
+
+static void ordinary_list_insert(struct ordinary_list *list, struct ordinary_node *node) {
+  if(!list->head) {
+    list->head = node;
+    list->tail = node;
+  } else if(list->head == list->tail) {
+    list->tail = node;
+    list->head->next = list->tail;
+    list->tail->prev = list->head;
+  } else {
+    list->tail->next = node;
+    node->prev = list->tail;
+    list->tail = node;
+  }
+
+  if(list->limit) {
+    list->count += 1;
+  }
+}
+
+struct ordinary_node *ordinary_list_add(struct ordinary_list *list, void *val) {
+  if(list->limit && list->count == list->limit) {
+    return NULL;
+  }
+
+  struct ordinary_node *node = malloc(sizeof(struct ordinary_node));
+
+  if(!node) {
+    return NULL;
+  }
+
+  node->prev = NULL;
+  node->next = NULL;
+  node->val = val;
+
+  ordinary_list_insert(list, node);
+
+  return node;
+}