diff --git a/lib/xy.h b/lib/xy.h
index 40fbeb8..a5a55a8 100644
--- a/lib/xy.h
+++ b/lib/xy.h
@@ -1356,14 +1356,14 @@ xy_seq_pop (XySeq_t *seq)
  * @flavor Ruby: Array#each
  */
 void
-xy_seq_each (XySeq_t *seq, void (*func)(void *))
+xy_seq_each (XySeq_t *seq, void (*func) (void *, void *), void *user_data)
 {
   xy_cant_be_null (seq);
   xy_cant_be_null (func);
 
   for (XySeqItem_t *it = seq->first_item; it; it = it->next)
     {
-      func (it->data);
+      func (it->data, user_data);
     }
 }
 
@@ -1371,14 +1371,14 @@ xy_seq_each (XySeq_t *seq, void (*func)(void *))
  * @flavor Ruby: Enumerable#find
  */
 void *
-xy_seq_find (XySeq_t *seq, bool (*func)(void *))
+xy_seq_find (XySeq_t *seq, bool (*func) (void *, void *), void *user_data)
 {
   xy_cant_be_null (seq);
   xy_cant_be_null (func);
 
   for (XySeqItem_t *it = seq->first_item; it; it = it->next)
     {
-      if (func (it->data))
+      if (func (it->data, user_data))
         {
           return it->data;
         }
@@ -1503,7 +1503,10 @@ xy_map_get (XyMap_t *map, const char *key)
  * @flavor Ruby: Hash#each
  */
 void
-xy_map_each (XyMap_t *map, void (*func)(const char *key, void *value))
+xy_map_each (
+  XyMap_t *map,
+  void (*func) (const char *key, void *value, void *user_data),
+  void *user_data)
 {
   xy_cant_be_null (map);
   xy_cant_be_null (func);
@@ -1513,7 +1516,7 @@ xy_map_each (XyMap_t *map, void (*func)(const char *key, void *value))
       struct _XyHashBucket_t *bucket = map->buckets[i];
       while (bucket)
         {
-          func (bucket->key, bucket->value);
+          func (bucket->key, bucket->value, user_data);
           bucket = bucket->next;
         }
     }
diff --git a/test/xy.c b/test/xy.c
index 26f0826..315a70c 100644
--- a/test/xy.c
+++ b/test/xy.c
@@ -5,7 +5,7 @@
  * Test Authors  : 曾奥然 <ccmywish@qq.com>
  * Contributors  : Mikachu2333  <mikachu.23333@zohomail.com>
  * Created On    : <2023-08-30>
- * Last Modified : <2025-08-21>
+ * Last Modified : <2025-08-22>
  *
  * Test xy.h
  * ------------------------------------------------------------*/
@@ -13,13 +13,13 @@
 #include "xy.h"
 
 void
-print_str_for_seq (void *str)
+print_str_for_seq (void *str, void *NOUSE)
 {
   print ((char *) str);
 }
 
 void
-print_str_for_map (const char *key, void *value)
+print_str_for_map (const char *key, void *value, void *NOUSE)
 {
   println (xy_strcat (4, "  ", key, " => ", (char *) value));
 }
@@ -150,7 +150,7 @@ main (int argc, char const *argv[])
   xy_seq_push (seq, "World");
   assert_str ("Hello", xy_seq_at (seq, 1));
   assert_str ("World", xy_seq_at (seq, 2));
-  xy_seq_each (seq, print_str_for_seq); br();
+  xy_seq_each (seq, print_str_for_seq, NULL); br();
   xy_seq_pop (seq);
   assert (1 == xy_seq_len (seq));
 
@@ -164,7 +164,7 @@ main (int argc, char const *argv[])
   assert_str ("chsrc", xy_map_get (map, "Hello"));
   assert (2 == xy_map_len (map));
   echo ("{");
-    xy_map_each (map, print_str_for_map);
+    xy_map_each (map, print_str_for_map, NULL);
   echo ("}");
 
   xy_succ ("测试完成", "xy.h 测试全部通过");