Commit 7310fd46 authored by Damien George's avatar Damien George
Browse files

py: Consolidate min/max functions into one, and add key= argument.

Addresses issue #811.
parent 1d8a0640
......@@ -284,63 +284,50 @@ STATIC mp_obj_t mp_builtin_iter(mp_obj_t o_in) {
MP_DEFINE_CONST_FUN_OBJ_1(mp_builtin_iter_obj, mp_builtin_iter);
STATIC mp_obj_t mp_builtin_max(uint n_args, const mp_obj_t *args) {
STATIC mp_obj_t mp_builtin_min_max(uint n_args, const mp_obj_t *args, mp_map_t *kwargs, int op) {
mp_map_elem_t *key_elem = mp_map_lookup(kwargs, MP_OBJ_NEW_QSTR(MP_QSTR_key), MP_MAP_LOOKUP);
mp_obj_t key_fn = key_elem == NULL ? MP_OBJ_NULL : key_elem->value;
if (n_args == 1) {
// given an iterable
mp_obj_t iterable = mp_getiter(args[0]);
mp_obj_t max_obj = NULL;
mp_obj_t best_key = MP_OBJ_NULL;
mp_obj_t best_obj = MP_OBJ_NULL;
mp_obj_t item;
while ((item = mp_iternext(iterable)) != MP_OBJ_STOP_ITERATION) {
if (max_obj == NULL || (mp_binary_op(MP_BINARY_OP_LESS, max_obj, item) == mp_const_true)) {
max_obj = item;
mp_obj_t key = key_fn == MP_OBJ_NULL ? item : mp_call_function_1(key_fn, item);
if (best_obj == MP_OBJ_NULL || (mp_binary_op(op, key, best_key) == mp_const_true)) {
best_key = key;
best_obj = item;
}
}
if (max_obj == NULL) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "max() arg is an empty sequence"));
if (best_obj == MP_OBJ_NULL) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "arg is an empty sequence"));
}
return max_obj;
return best_obj;
} else {
// given many args
mp_obj_t max_obj = args[0];
for (int i = 1; i < n_args; i++) {
if (mp_binary_op(MP_BINARY_OP_LESS, max_obj, args[i]) == mp_const_true) {
max_obj = args[i];
mp_obj_t best_key = MP_OBJ_NULL;
mp_obj_t best_obj = MP_OBJ_NULL;
for (mp_uint_t i = 0; i < n_args; i++) {
mp_obj_t key = key_fn == MP_OBJ_NULL ? args[i] : mp_call_function_1(key_fn, args[i]);
if (best_obj == MP_OBJ_NULL || (mp_binary_op(op, key, best_key) == mp_const_true)) {
best_key = key;
best_obj = args[i];
}
}
return max_obj;
return best_obj;
}
}
MP_DEFINE_CONST_FUN_OBJ_VAR(mp_builtin_max_obj, 1, mp_builtin_max);
STATIC mp_obj_t mp_builtin_min(uint n_args, const mp_obj_t *args) {
if (n_args == 1) {
// given an iterable
mp_obj_t iterable = mp_getiter(args[0]);
mp_obj_t min_obj = NULL;
mp_obj_t item;
while ((item = mp_iternext(iterable)) != MP_OBJ_STOP_ITERATION) {
if (min_obj == NULL || (mp_binary_op(MP_BINARY_OP_LESS, item, min_obj) == mp_const_true)) {
min_obj = item;
}
}
if (min_obj == NULL) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "min() arg is an empty sequence"));
}
return min_obj;
} else {
// given many args
mp_obj_t min_obj = args[0];
for (int i = 1; i < n_args; i++) {
if (mp_binary_op(MP_BINARY_OP_LESS, args[i], min_obj) == mp_const_true) {
min_obj = args[i];
}
}
return min_obj;
}
STATIC mp_obj_t mp_builtin_max(uint n_args, const mp_obj_t *args, mp_map_t *kwargs) {
return mp_builtin_min_max(n_args, args, kwargs, MP_BINARY_OP_MORE);
}
MP_DEFINE_CONST_FUN_OBJ_KW(mp_builtin_max_obj, 1, mp_builtin_max);
MP_DEFINE_CONST_FUN_OBJ_VAR(mp_builtin_min_obj, 1, mp_builtin_min);
STATIC mp_obj_t mp_builtin_min(uint n_args, const mp_obj_t *args, mp_map_t *kwargs) {
return mp_builtin_min_max(n_args, args, kwargs, MP_BINARY_OP_LESS);
}
MP_DEFINE_CONST_FUN_OBJ_KW(mp_builtin_min_obj, 1, mp_builtin_min);
STATIC mp_obj_t mp_builtin_next(mp_obj_t o) {
mp_obj_t ret = mp_iternext_allow_raise(o);
......
......@@ -13,3 +13,13 @@ print(max(-1,0))
print(min([1,2,4,0,-1,2]))
print(max([1,2,4,0,-1,2]))
# test with key function
lst = [2, 1, 3, 4]
print(min(lst, key=lambda x:x))
print(min(lst, key=lambda x:-x))
print(min(1, 2, 3, 4, key=lambda x:-x))
print(min(4, 3, 2, 1, key=lambda x:-x))
print(max(lst, key=lambda x:x))
print(max(lst, key=lambda x:-x))
print(max(1, 2, 3, 4, key=lambda x:-x))
print(max(4, 3, 2, 1, key=lambda x:-x))
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