根据实测情况来看，iter的方案是可行的，后续再考虑实现细节吧

.vscode/settings.json

@@ -24,6 +24,7 @@
         "unity_internals.h": "c",
         "stdarg.h": "c",
         "graph.h": "c",
-        "unicstl_config.h": "c"
+        "unicstl_config.h": "c",
+        "iter.h": "c"
     }
 }

include/iter.h

@@ -0,0 +1,32 @@
+/**
+ * @file iter.h
+ * @author wenjf (Orig5826@163.com)
+ * @brief
+ * @version 0.1
+ * @date 2025-04-23
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+#ifndef _ITER_H_
+#define _ITER_H_
+
+#include "common.h"
+
+struct _iterator
+{
+    void* obj;
+    void* self;
+    void* parent;
+
+    void* (*begin)(struct _iterator* self);
+    void* (*next)(struct _iterator* self);
+    void* (*end)(struct _iterator* self);
+
+    bool (*hasnext)(struct _iterator* self);
+
+    void* (*data)(struct _iterator* self);
+};
+typedef struct _iterator* iterator_t;
+
+#endif // !_ITER_H_

include/list.h

@@ -12,6 +12,7 @@
 #define _LIST_H_
 
 #include "common.h"
+#include "iter.h"
 
 struct _list
 {
@@ -23,6 +24,9 @@ struct _list
     uint32_t _ratio;
     uint32_t _cur;
 
+    struct _iterator _iter;
+    iterator_t (*iter)(struct _list* self);
+
     // kernel
     bool (*append)(struct _list* self, void* obj);                      // Append object to the end of the list.
     bool (*insert)(struct _list* self, int index, void* obj);           // Insert object before index.

src/list.c

@@ -250,6 +250,57 @@ static bool list_init2(struct _list* list, uint32_t obj_size, uint32_t capacity)
     return true;
 }
 
+iterator_t list_iter(struct _list* self)
+{
+    self->_cur = 0;
+    self->_iter.obj = self->obj;
+    return &self->_iter;
+}
+
+static void* list_iter_begin(struct _iterator* iter)
+{
+    list_t self = (list_t)iter->parent;
+    self->_cur = 0;
+    iter->obj = self->obj;
+    return iter;
+}
+
+static void* list_iter_end(struct _iterator* iter)
+{
+    list_t self = (list_t)iter->parent;
+    iter->obj = (char*)self->obj + self->_size * self->_obj_size;
+    return iter;
+}
+
+static void* list_iter_next(struct _iterator* iter)
+{
+    list_t self = (list_t)iter->parent;
+
+    // if add this, can't go to end
+    // if(self->_cur < self->_size - 1)
+    {
+        self->_cur += 1;
+    }
+    iter->obj = (char*)self->obj + self->_cur * self->_obj_size;
+    return iter;
+}
+
+static bool list_iter_hasnext(struct _iterator* iter)
+{
+    list_t self = (list_t)iter->parent;
+
+    if(self->_cur < self->_size)
+    {
+        return true;
+    }
+    return false;
+}
+
+static void* list_iter_data(struct _iterator* iter)
+{
+    return iter->obj;
+}
+
 list_t list_new2(uint32_t obj_size, uint32_t capacity)
 {
     struct _list* list = NULL;
@@ -259,9 +310,21 @@ list_t list_new2(uint32_t obj_size, uint32_t capacity)
         if(list_init2(list, obj_size, capacity) != true)
         {
             free(list);
-            list = NULL;
+            // list = NULL;
+            return NULL;
         }
     }
+
+    list->_iter.self = &list->iter;
+    list->_iter.parent = list;
+
+    list->_iter.begin = list_iter_begin;
+    list->_iter.next = list_iter_next;
+    list->_iter.end = list_iter_end;
+    list->_iter.data = list_iter_data;
+    list->_iter.hasnext = list_iter_hasnext;
+
+    list->iter = list_iter;
     return list;
 }
 

test/test_list.c

@@ -328,6 +328,47 @@ static void test_list_iter(void)
     list_free(&list);
 }
 
+void list_iter_test(void)
+{
+    int temp = 0;
+    int data[] = { 1,2,3,4,5,6,7,8,9,10 };
+    uint32_t len = sizeof(data) / sizeof(data[0]);
+    uint32_t i = 0;
+
+    list_t list = NULL;
+
+    // ------------------------------
+    list = list_new2(sizeof(int), len);
+    TEST_ASSERT_TRUE(list->empty(list));
+    list->print_obj = print_num;
+
+    for(i = 0; i < len; i++)
+    {
+        TEST_ASSERT_TRUE(list->append(list, &data[i]));
+        TEST_ASSERT_EQUAL_INT(i + 1, list->size(list));
+
+        TEST_ASSERT_TRUE(list->get(list, i, &temp));
+        TEST_ASSERT_EQUAL_INT(data[i], temp);
+
+        TEST_ASSERT_FALSE(list->empty(list));
+    }
+
+    iterator_t it = list->iter(list);
+    printf("iter start\n");
+    list->print(list);
+
+    printf("\n");
+    while(it->hasnext(it))
+    {
+        int dd = *(int*)it->data(it);
+        printf("%d ", dd);
+        it->next(it);
+    }
+    printf("\niter end\n");
+
+    list_free(&list);
+}
+
 void test_list(void)
 {
     UnitySetTestFile(__FILE__);
@@ -341,4 +382,6 @@ void test_list(void)
     RUN_TEST(test_list_struct);
 
     RUN_TEST(test_list_iter);
+
+    RUN_TEST(list_iter_test);
 }