diff --git a/v3/CMakeLists.txt b/v3/CMakeLists.txt
index 865f2c0..85e561c 100644
--- a/v3/CMakeLists.txt
+++ b/v3/CMakeLists.txt
@@ -13,4 +13,5 @@ add_test(NAME q2insort_ut COMMAND q2insort_ut)
 add_test(NAME binsearch_ut COMMAND binsearch_ut)
 add_test(NAME hmap_demo_ut COMMAND hmap_demo_ut)
 add_test(NAME ivec_sort_ut COMMAND ivec_sort_ut)
-add_test(NAME ivec_put_rem_demo_ut COMMAND ivec_put_rem_demo_ut)
\ No newline at end of file
+add_test(NAME ivec_put_rem_demo_ut COMMAND ivec_put_rem_demo_ut)
+add_test(NAME slist_demo_ut COMMAND slist_demo_ut)
\ No newline at end of file
diff --git a/v3/algo.h b/v3/algo.h
index 06db0f4..7390235 100644
--- a/v3/algo.h
+++ b/v3/algo.h
@@ -146,7 +146,7 @@ static void heapsort(void *a, int n, int sz,
   }
 }
 
-#define VHEAPSORT(v, order) heapsort(v->elems, v->sz, sizeof(v->elems[0]), order)
-#define VQ2INSORT(v, order) q2insort(v->elems, v->sz, sizeof(v->elems[0]), order)
+#define VHEAPSORT(v, order) heapsort(v->elems, v->size, sizeof(v->elems[0]), order)
+#define VQ2INSORT(v, order) q2insort(v->elems, v->size, sizeof(v->elems[0]), order)
 
 #endif  // ALGO_H_
\ No newline at end of file
diff --git a/v3/hmap.h b/v3/hmap.h
index 71ff4e0..619ae67 100644
--- a/v3/hmap.h
+++ b/v3/hmap.h
@@ -75,7 +75,7 @@ struct pre##hmap { \
   struct pre##hmap_node *end; \
   int mod; \
   unsigned mask; \
-  int sz; \
+  int size; \
   int cap; \
   int used; \
   unsigned (*ha)(key_t); \
@@ -145,7 +145,7 @@ static void relocate_map(struct pre##hmap *hm, unsigned ocap, \
 } \
 static void pre##hmap_realloc(struct pre##hmap *hm) { \
   int ocap = hm->cap; \
-  pre##hmap_set_shift_from_cap(hm, hm->sz * 1.333); \
+  pre##hmap_set_shift_from_cap(hm, hm->size * 1.333); \
   if (hm->cap > ocap) { \
     pre##hmap_realloc_arrays(hm); \
     memset(hm->nodes + ocap, 0, (hm->cap - ocap) * sizeof(struct pre##hmap_node)); \
@@ -156,11 +156,11 @@ static void pre##hmap_realloc(struct pre##hmap *hm) { \
   if (hm->cap < ocap) { \
     pre##hmap_realloc_arrays(hm); \
   } \
-  hm->used = hm->sz; \
+  hm->used = hm->size; \
 } \
 static inline int pre##hmap_maybe_realloc(struct pre##hmap *hm) { \
   unsigned used = hm->used, cap = hm->cap; \
-  if ((cap > hm->sz * 4 && cap > 1 << HASH_MIN_SHIFT) || \
+  if ((cap > hm->size * 4 && cap > 1 << HASH_MIN_SHIFT) || \
       (cap <= used + (used/16))) { \
     pre##hmap_realloc(hm); \
     return 1; \
@@ -170,7 +170,7 @@ static inline int pre##hmap_maybe_realloc(struct pre##hmap *hm) { \
 static struct pre##hmap_node *pre##hmap_rem_node(struct pre##hmap *hm, int idx) { \
   struct pre##hmap_node *n = hm->nodes + idx; \
   n->state = DELETED; \
-  hm->sz--; \
+  hm->size--; \
   return n; \
 } \
 static inline int pre##hmap_lookup(struct pre##hmap *hm, key_t key, \
@@ -203,7 +203,7 @@ static inline int pre##hmap_lookup(struct pre##hmap *hm, key_t key, \
 } \
 struct pre##hmap *pre##hmap(int shift, unsigned (*ha)(), int (*eq)()) { \
   struct pre##hmap *hm = malloc(sizeof(struct pre##hmap)); \
-  hm->sz = 0; \
+  hm->size = 0; \
   hm->used = 0; \
   hm->ha = ha; \
   hm->eq = eq; \
@@ -220,7 +220,7 @@ struct pre##hmap_node *pre##hmap_put(struct pre##hmap *hm, key_t k, value_t v) {
   n->hash = key_hash; \
   n->key = k; \
   n->value = v; \
-  ++hm->sz; \
+  ++hm->size; \
   int new_usage = n->state == UNUSED; \
   n->state = USING; \
   if (new_usage) { \
diff --git a/v3/slist.h b/v3/slist.h
new file mode 100644
index 0000000..69ce111
--- /dev/null
+++ b/v3/slist.h
@@ -0,0 +1,119 @@
+#ifndef SLIST_H_
+#define SLIST_H_
+
+#include <stdlib.h>
+
+#define SDECL(sname, elem_t) \
+struct sname##_node; \
+struct sname; \
+struct sname##_node *sname##_node(elem_t value); \
+struct sname *sname(); \
+void sname##_del(struct sname *list); \
+struct sname *sname##_append(struct sname *list, elem_t value); \
+struct sname *sname##_prepend(struct sname *list, elem_t value); \
+struct sname *sname##_dfirst(struct sname *list); \
+struct sname *sname##_push(struct sname *list, elem_t elem); \
+elem_t *sname##_top(struct sname *list); \
+struct sname *sname##_pop(struct sname *list); \
+struct sname *sname##_enque(struct sname *list, elem_t elem); \
+elem_t *sname##_peek(struct sname *list); \
+struct sname *sname##_deque(struct sname *list); \
+int sname##_empty(struct sname *list);
+
+#define SIMPL(sname, elem_t) \
+struct sname##_node { \
+  elem_t value; \
+  struct sname##_node *next; \
+}; \
+struct sname { \
+  struct sname##_node *first; \
+  struct sname##_node *last; \
+  int size; \
+}; \
+\
+struct sname##_node *sname##_node(elem_t value) { \
+  struct sname##_node *tmp = malloc(sizeof(struct sname##_node)); \
+  tmp->value = value; \
+  tmp->next = NULL; \
+  return tmp; \
+} \
+struct sname *sname() { \
+  struct sname *tmp = malloc(sizeof(struct sname)); \
+  tmp->first = tmp->last = NULL; \
+  tmp->size = 0; \
+  return tmp; \
+} \
+void sname##_del(struct sname *list) { \
+  while (!sname##_empty(list)) { \
+    sname##_dfirst(list); \
+  } \
+  free(list); \
+} \
+struct sname *sname##_append(struct sname *list, elem_t value) {\
+  struct sname##_node *node = sname##_node(value); \
+  if (!node) { \
+    return NULL; \
+  } \
+  if (list->first == NULL) { \
+    list->first = list->last = node; \
+  } else { \
+    list->last->next = node; \
+    list->last = node; \
+  } \
+  ++list->size; \
+  return list; \
+} \
+struct sname *sname##_prepend(struct sname *list, elem_t value) {\
+  struct sname##_node *node = sname##_node(value); \
+  if (!node) { \
+    return NULL; \
+  } \
+  if (list->first == NULL) { \
+    list->first = list->last = node; \
+  } else { \
+    node->next = list->first; \
+    list->first = node; \
+  } \
+  ++list->size; \
+  return list; \
+} \
+struct sname *sname##_dfirst(struct sname *list) {\
+  if (!list || sname##_empty(list)) { \
+    return NULL; \
+  } \
+  if (list->first == list->last) { \
+    list->last = NULL; \
+  } \
+  struct sname##_node *tmp = list->first; \
+  list->first = tmp->next; \
+  free(tmp); \
+  --list->size; \
+  return list; \
+} \
+struct sname *sname##_push(struct sname *list, elem_t elem) { \
+  return sname##_prepend(list, elem); \
+} \
+elem_t *sname##_top(struct sname *list) { \
+  return &list->first->value; \
+} \
+struct sname *sname##_pop(struct sname *list) {\
+  return sname##_dfirst(list); \
+} \
+struct sname *sname##_enque(struct sname *list, elem_t elem) { \
+  return sname##_append(list, elem); \
+} \
+elem_t *sname##_peek(struct sname *list) {\
+  return &list->first->value; \
+} \
+struct sname *sname##_deque(struct sname *list) { \
+  return sname##_dfirst(list); \
+} \
+int sname##_empty(struct sname *list) { \
+  return list->first == NULL || list->last == NULL; \
+}
+
+#define SDECL_IMPL(sname, elem_t) \
+SDECL(sname, elem_t) \
+SIMPL(sname, elem_t)
+
+#endif  // SLIST_H_
\ No newline at end of file
diff --git a/v3/tests/CMakeLists.txt b/v3/tests/CMakeLists.txt
index ad379ae..2a8409b 100644
--- a/v3/tests/CMakeLists.txt
+++ b/v3/tests/CMakeLists.txt
@@ -4,4 +4,5 @@ add_executable(q2insort_ut q2insort_ut.c)
 add_executable(binsearch_ut binsearch_ut.c)
 add_executable(hmap_demo_ut hmap_demo_ut.c)
 add_executable(ivec_sort_ut ivec_sort_ut.c)
-add_executable(ivec_put_rem_demo_ut ivec_put_rem_demo_ut.c)
\ No newline at end of file
+add_executable(ivec_put_rem_demo_ut ivec_put_rem_demo_ut.c)
+add_executable(slist_demo_ut slist_demo_ut.c)
\ No newline at end of file
diff --git a/v3/tests/ivec_put_rem_demo_ut.c b/v3/tests/ivec_put_rem_demo_ut.c
index 5971921..8f704b4 100644
--- a/v3/tests/ivec_put_rem_demo_ut.c
+++ b/v3/tests/ivec_put_rem_demo_ut.c
@@ -7,8 +7,8 @@
 VEC_DECL_IMPL(i, int)
 
 void ivec_print(struct ivector *v) {
-  printf("sz: %d\ncap: %d\n", v->sz, v->cap);
-  for (int i = 0; i < v->sz; ++i) {
+  printf("sz: %d\ncap: %d\n", v->size, v->cap);
+  for (int i = 0; i < v->size; ++i) {
     printf("%d\n", v->elems[i]);
   }
 }
diff --git a/v3/tests/ivec_sort_ut.c b/v3/tests/ivec_sort_ut.c
index b7d03fe..e0f7fe6 100644
--- a/v3/tests/ivec_sort_ut.c
+++ b/v3/tests/ivec_sort_ut.c
@@ -18,13 +18,13 @@ int main() {
     ivec_append(v, rand());
   }
   VQ2INSORT(v, lte);
-  for (int i = 0; i < v->sz; ++i) {
+  for (int i = 0; i < v->size; ++i) {
     if (i > 0 && !lte(v->elems + i - 1, v->elems + i)) {
       return 1;
     }
   }
-  printf("sz: %d\ncap: %d\n", v->sz, v->cap);
-  for (int i = 0; i < v->sz; ++i) {
+  printf("sz: %d\ncap: %d\n", v->size, v->cap);
+  for (int i = 0; i < v->size; ++i) {
     printf("%d\n", v->elems[i]);
   }
   ivec_del(v);
diff --git a/v3/tests/ivec_ut.c b/v3/tests/ivec_ut.c
index 9674ac5..31db164 100644
--- a/v3/tests/ivec_ut.c
+++ b/v3/tests/ivec_ut.c
@@ -9,7 +9,7 @@ int main() {
   for (int i = 0; i < 5; ++i) {
     ivec_append(v, i);
   }
-  printf("sz = %d\ncap = %d\n", v->sz, v->cap);
+  printf("sz = %d\ncap = %d\n", v->size, v->cap);
   for (int i = 0; i < 5; ++i) {
     printf("%d ", v->elems[i]);
   }
diff --git a/v3/tests/slist_demo_ut.c b/v3/tests/slist_demo_ut.c
new file mode 100644
index 0000000..39b240d
--- /dev/null
+++ b/v3/tests/slist_demo_ut.c
@@ -0,0 +1,27 @@
+#include "slist.h"
+
+#include <stdio.h>
+
+SDECL_IMPL(slist, int)
+
+void print_lst(struct slist *lst) {
+  printf("size = %d\n", lst->size);
+  for (struct slist_node *n = lst->first; n; n = n->next) {
+    printf("%d ", n->value);
+  }
+  printf("\n");
+}
+
+int main() {
+  struct slist *lst = slist();
+  slist_append(lst, 1);
+  slist_append(lst, 3);
+  slist_append(lst, 5);
+  slist_prepend(lst, 2);
+  slist_prepend(lst, 6);
+  print_lst(lst);
+  slist_dfirst(lst);
+  slist_dfirst(lst);
+  print_lst(lst);
+  slist_del(lst);
+}
\ No newline at end of file
diff --git a/v3/vec.h b/v3/vec.h
index 11e8ff9..5778f85 100644
--- a/v3/vec.h
+++ b/v3/vec.h
@@ -18,37 +18,37 @@ void pre##vec_del(struct pre##vector *v);
 
 #define VEC_IMPL(pre, elem_t) \
 struct pre##vector { \
-  int sz; \
+  int size; \
   int cap; \
   elem_t *elems; \
 }; \
 struct pre##vector *pre##vector(int n) {  \
   struct pre##vector *v = malloc(sizeof(struct pre##vector)); \
-  v->sz = n; \
-  v->cap = v->sz > 0? v->sz: 8; \
+  v->size = n; \
+  v->cap = v->size > 0? v->size: 8; \
   v->elems = calloc(v->cap, sizeof(elem_t)); \
   return v; \
 } \
 elem_t pre##vec_rem(struct pre##vector *v, int idx) { \
   elem_t tmp = v->elems[idx]; \
-  for (int i = idx; i < v->sz - 1; ++i) { \
+  for (int i = idx; i < v->size - 1; ++i) { \
     v->elems[i] = v->elems[i + 1]; \
   } \
-  --v->sz; \
-  if (v->sz > 8 && v->cap > v->sz * 2) { \
-    pre##vec_reserve(v, v->sz * 1.33); \
+  --v->size; \
+  if (v->size > 8 && v->cap > v->size * 2) { \
+    pre##vec_reserve(v, v->size * 1.33); \
   } \
   return tmp; \
 } \
 void pre##vec_put(struct pre##vector *v, elem_t elem, int idx) { \
   pre##vec_append(v, elem); \
-  for (int i = v->sz; i > idx; --i) { \
+  for (int i = v->size; i > idx; --i) { \
     v->elems[i] = v->elems[i - 1]; \
   } \
   v->elems[idx] = elem; \
 } \
 int pre##vec_reserve(struct pre##vector *v, int newcap) { \
-  if (newcap <= v->sz) { \
+  if (newcap <= v->size) { \
     return 1; \
   } \
   v->elems = realloc(v->elems, newcap * sizeof(elem_t)); \
@@ -61,17 +61,17 @@ int pre##vec_reserve(struct pre##vector *v, int newcap) { \
 void pre##vec_append(struct pre##vector *v, elem_t value) { \
   if (v->cap == 0) { \
     pre##vec_reserve(v, 16); \
-  } else if (v->sz == v->cap) { \
+  } else if (v->size == v->cap) { \
     pre##vec_reserve(v, 2 * v->cap); \
   } \
-  v->elems[v->sz] = value; \
-  ++v->sz; \
+  v->elems[v->size] = value; \
+  ++v->size; \
 } \
 void pre##vec_resize(struct pre##vector *v, int newsize) { \
   if (newsize > v->cap) { \
     pre##vec_reserve(v, newsize); \
   } \
-  v->sz = newsize; \
+  v->size = newsize; \
 } \
 void pre##vec_del(struct pre##vector *v) { \
   if (!v) { \