diff --git a/py/objlist.c b/py/objlist.c
index ade062e07c663def761e65d7cbdc40fae82aba40..0ff3b1d53d00d815ca60ab355378b0748671b7e1 100644
--- a/py/objlist.c
+++ b/py/objlist.c
@@ -31,6 +31,7 @@
#include "py/objlist.h"
#include "py/runtime0.h"
#include "py/runtime.h"
+#include "py/stackctrl.h"
STATIC mp_obj_t mp_obj_new_list_iterator(mp_obj_list_t *list, mp_uint_t cur);
STATIC mp_obj_list_t *list_new(mp_uint_t n);
@@ -284,16 +285,15 @@ STATIC mp_obj_t list_pop(mp_uint_t n_args, const mp_obj_t *args) {
return ret;
}
-// TODO make this conform to CPython's definition of sort
-STATIC void mp_quicksort(mp_obj_t *head, mp_obj_t *tail, mp_obj_t key_fn, bool reversed) {
- mp_uint_t op = reversed ? MP_BINARY_OP_MORE : MP_BINARY_OP_LESS;
+STATIC void mp_quicksort(mp_obj_t *head, mp_obj_t *tail, mp_obj_t key_fn, mp_obj_t binop_less_result) {
+ MP_STACK_CHECK();
while (head < tail) {
mp_obj_t *h = head - 1;
mp_obj_t *t = tail;
- mp_obj_t v = key_fn == NULL ? tail[0] : mp_call_function_1(key_fn, tail[0]); // get pivot using key_fn
+ mp_obj_t v = key_fn == MP_OBJ_NULL ? tail[0] : mp_call_function_1(key_fn, tail[0]); // get pivot using key_fn
for (;;) {
- do ++h; while (mp_binary_op(op, key_fn == NULL ? h[0] : mp_call_function_1(key_fn, h[0]), v) == mp_const_true);
- do --t; while (h < t && mp_binary_op(op, v, key_fn == NULL ? t[0] : mp_call_function_1(key_fn, t[0])) == mp_const_true);
+ do ++h; while (h < t && mp_binary_op(MP_BINARY_OP_LESS, key_fn == MP_OBJ_NULL ? h[0] : mp_call_function_1(key_fn, h[0]), v) == binop_less_result);
+ do --t; while (h < t && mp_binary_op(MP_BINARY_OP_LESS, v, key_fn == MP_OBJ_NULL ? t[0] : mp_call_function_1(key_fn, t[0])) == binop_less_result);
if (h >= t) break;
mp_obj_t x = h[0];
h[0] = t[0];
@@ -302,27 +302,38 @@ STATIC void mp_quicksort(mp_obj_t *head, mp_obj_t *tail, mp_obj_t key_fn, bool r
mp_obj_t x = h[0];
h[0] = tail[0];
tail[0] = x;
- mp_quicksort(head, t, key_fn, reversed);
- head = h + 1;
+ // do the smaller recursive call first, to keep stack within O(log(N))
+ if (t - head < tail - h - 1) {
+ mp_quicksort(head, t, key_fn, binop_less_result);
+ head = h + 1;
+ } else {
+ mp_quicksort(h + 1, tail, key_fn, binop_less_result);
+ tail = t;
+ }
}
}
-mp_obj_t mp_obj_list_sort(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kwargs) {
- assert(n_args >= 1);
- assert(MP_OBJ_IS_TYPE(args[0], &mp_type_list));
- if (n_args > 1) {
- nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError,
- "list.sort takes no positional arguments"));
- }
- mp_obj_list_t *self = args[0];
+// TODO Python defines sort to be stable but ours is not
+mp_obj_t mp_obj_list_sort(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+ static const mp_arg_t allowed_args[] = {
+ { MP_QSTR_key, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
+ { MP_QSTR_reverse, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} },
+ };
+
+ // parse args
+ mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+ mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+ mp_obj_list_t *self = pos_args[0];
+ assert(MP_OBJ_IS_TYPE(self, &mp_type_list));
+
if (self->len > 1) {
- mp_map_elem_t *keyfun = mp_map_lookup(kwargs, MP_OBJ_NEW_QSTR(MP_QSTR_key), MP_MAP_LOOKUP);
- mp_map_elem_t *reverse = mp_map_lookup(kwargs, MP_OBJ_NEW_QSTR(MP_QSTR_reverse), MP_MAP_LOOKUP);
mp_quicksort(self->items, self->items + self->len - 1,
- keyfun ? keyfun->value : NULL,
- reverse && reverse->value ? mp_obj_is_true(reverse->value) : false);
+ args[0].u_obj == mp_const_none ? MP_OBJ_NULL : args[0].u_obj,
+ args[1].u_bool ? mp_const_false : mp_const_true);
}
- return mp_const_none; // return None, as per CPython
+
+ return mp_const_none;
}
STATIC mp_obj_t list_clear(mp_obj_t self_in) {
@@ -412,7 +423,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_3(list_insert_obj, list_insert);
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(list_pop_obj, 1, 2, list_pop);
STATIC MP_DEFINE_CONST_FUN_OBJ_2(list_remove_obj, list_remove);
STATIC MP_DEFINE_CONST_FUN_OBJ_1(list_reverse_obj, list_reverse);
-STATIC MP_DEFINE_CONST_FUN_OBJ_KW(list_sort_obj, 0, mp_obj_list_sort);
+STATIC MP_DEFINE_CONST_FUN_OBJ_KW(list_sort_obj, 1, mp_obj_list_sort);
STATIC const mp_map_elem_t list_locals_dict_table[] = {
{ MP_OBJ_NEW_QSTR(MP_QSTR_append), (mp_obj_t)&list_append_obj },
diff --git a/tests/basics/list_sort.py b/tests/basics/list_sort.py
index e323ff1c2cc564162f8f76cf35b04d9fccda8929..c185ddcd16817cd60403601332d0fe249d5c1643 100644
--- a/tests/basics/list_sort.py
+++ b/tests/basics/list_sort.py
@@ -26,3 +26,24 @@ l.sort(reverse=False)
print(l)
print(l == sorted(l, reverse=False))
+# test large lists (should not stack overflow)
+l = list(range(2000))
+l.sort()
+print(l[0], l[-1])
+l.sort(reverse=True)
+print(l[0], l[-1])
+
+# test user-defined ordering
+class A:
+ def __init__(self, x):
+ self.x = x
+ def __lt__(self, other):
+ return self.x > other.x
+ def __repr__(self):
+ return str(self.x)
+l = [A(5), A(2), A(1), A(3), A(4)]
+print(l)
+l.sort()
+print(l)
+l.sort(reverse=True)
+print(l)