circuitpython/py/sequence.c
2021-05-03 14:01:18 -07:00

292 lines
8.8 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* SPDX-FileCopyrightText: Copyright (c) 2013, 2014 Damien P. George
* Copyright (c) 2014 Paul Sokolovsky
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <string.h>
#include "py/runtime.h"
#include "supervisor/shared/translate.h"
// Helpers for sequence types
#define SWAP(type, var1, var2) { type t = var2; var2 = var1; var1 = t; }
#if __GNUC__ < 5
// n.b. does not actually detect overflow!
#define __builtin_mul_overflow(a, b, x) (*(x) = (a) * (b), false)
#endif
// Detect when a multiply causes an overflow.
size_t mp_seq_multiply_len(size_t item_sz, size_t len) {
size_t new_len;
if (__builtin_mul_overflow(item_sz, len, &new_len)) {
mp_raise_msg(&mp_type_OverflowError, translate("small int overflow"));
}
return new_len;
}
// Implements backend of sequence * integer operation. Assumes elements are
// memory-adjacent in sequence.
void mp_seq_multiply(const void *items, size_t item_sz, size_t len, size_t times, void *dest) {
for (size_t i = 0; i < times; i++) {
size_t copy_sz = item_sz * len;
memcpy(dest, items, copy_sz);
dest = (char *)dest + copy_sz;
}
}
#if MICROPY_PY_BUILTINS_SLICE
bool mp_seq_get_fast_slice_indexes(mp_uint_t len, mp_obj_t slice, mp_bound_slice_t *indexes) {
mp_obj_t ostart, ostop, ostep;
mp_int_t start, stop;
mp_obj_slice_get(slice, &ostart, &ostop, &ostep);
if (ostep != mp_const_none && ostep != MP_OBJ_NEW_SMALL_INT(1)) {
indexes->step = mp_obj_get_int(ostep);
if (indexes->step == 0) {
mp_raise_ValueError(translate("slice step cannot be zero"));
}
} else {
indexes->step = 1;
}
if (ostart == mp_const_none) {
if (indexes->step > 0) {
start = 0;
} else {
start = len - 1;
}
} else {
start = mp_obj_get_int(ostart);
}
if (ostop == mp_const_none) {
if (indexes->step > 0) {
stop = len;
} else {
stop = 0;
}
} else {
stop = mp_obj_get_int(ostop);
if (stop >= 0 && indexes->step < 0) {
stop += 1;
}
}
// Unlike subscription, out-of-bounds slice indexes are never error
if (start < 0) {
start = len + start;
if (start < 0) {
if (indexes->step < 0) {
start = -1;
} else {
start = 0;
}
}
} else if (indexes->step > 0 && (mp_uint_t)start > len) {
start = len;
} else if (indexes->step < 0 && (mp_uint_t)start >= len) {
start = len - 1;
}
if (stop < 0) {
stop = len + stop;
if (stop < 0) {
stop = -1;
}
if (indexes->step < 0) {
stop += 1;
}
} else if ((mp_uint_t)stop > len) {
stop = len;
}
// CPython returns empty sequence in such case, or point for assignment is at start
if (indexes->step > 0 && start > stop) {
stop = start;
} else if (indexes->step < 0 && start < stop) {
stop = start + 1;
}
indexes->start = start;
indexes->stop = stop;
return indexes->step == 1;
}
#endif
mp_obj_t mp_seq_extract_slice(size_t len, const mp_obj_t *seq, mp_bound_slice_t *indexes) {
(void)len; // TODO can we remove len from the arg list?
mp_int_t start = indexes->start, stop = indexes->stop;
mp_int_t step = indexes->step;
mp_obj_t res = mp_obj_new_list(0, NULL);
if (step < 0) {
while (start >= stop) {
mp_obj_list_append(res, seq[start]);
start += step;
}
} else {
while (start < stop) {
mp_obj_list_append(res, seq[start]);
start += step;
}
}
return res;
}
// Special-case comparison function for sequences of bytes
// Don't pass MP_BINARY_OP_NOT_EQUAL here
bool mp_seq_cmp_bytes(mp_uint_t op, const byte *data1, size_t len1, const byte *data2, size_t len2) {
if (op == MP_BINARY_OP_EQUAL && len1 != len2) {
return false;
}
// Let's deal only with > & >=
if (op == MP_BINARY_OP_LESS || op == MP_BINARY_OP_LESS_EQUAL) {
SWAP(const byte *, data1, data2);
SWAP(size_t, len1, len2);
if (op == MP_BINARY_OP_LESS) {
op = MP_BINARY_OP_MORE;
} else {
op = MP_BINARY_OP_MORE_EQUAL;
}
}
size_t min_len = len1 < len2 ? len1 : len2;
int res = memcmp(data1, data2, min_len);
if (op == MP_BINARY_OP_EQUAL) {
// If we are checking for equality, here's the answer
return res == 0;
}
if (res < 0) {
return false;
}
if (res > 0) {
return true;
}
// If we had tie in the last element...
// ... and we have lists of different lengths...
if (len1 != len2) {
if (len1 < len2) {
// ... then longer list length wins (we deal only with >)
return false;
}
} else if (op == MP_BINARY_OP_MORE) {
// Otherwise, if we have strict relation, equality means failure
return false;
}
return true;
}
// Special-case comparison function for sequences of mp_obj_t
// Don't pass MP_BINARY_OP_NOT_EQUAL here
bool mp_seq_cmp_objs(mp_uint_t op, const mp_obj_t *items1, size_t len1, const mp_obj_t *items2, size_t len2) {
if (op == MP_BINARY_OP_EQUAL && len1 != len2) {
return false;
}
// Let's deal only with > & >=
if (op == MP_BINARY_OP_LESS || op == MP_BINARY_OP_LESS_EQUAL) {
SWAP(const mp_obj_t *, items1, items2);
SWAP(size_t, len1, len2);
if (op == MP_BINARY_OP_LESS) {
op = MP_BINARY_OP_MORE;
} else {
op = MP_BINARY_OP_MORE_EQUAL;
}
}
size_t len = len1 < len2 ? len1 : len2;
for (size_t i = 0; i < len; i++) {
// If current elements equal, can't decide anything - go on
if (mp_obj_equal(items1[i], items2[i])) {
continue;
}
// Othewise, if they are not equal, we can have final decision based on them
if (op == MP_BINARY_OP_EQUAL) {
// In particular, if we are checking for equality, here're the answer
return false;
}
// Otherwise, application of relation op gives the answer
return mp_binary_op(op, items1[i], items2[i]) == mp_const_true;
}
// If we had tie in the last element...
// ... and we have lists of different lengths...
if (len1 != len2) {
if (len1 < len2) {
// ... then longer list length wins (we deal only with >)
return false;
}
} else if (op == MP_BINARY_OP_MORE) {
// Otherwise, if we have strict relation, sequence equality means failure
return false;
}
return true;
}
// Special-case of index() which searches for mp_obj_t
mp_obj_t mp_seq_index_obj(const mp_obj_t *items, size_t len, size_t n_args, const mp_obj_t *args) {
mp_obj_type_t *type = mp_obj_get_type(args[0]);
mp_obj_t value = args[1];
size_t start = 0;
size_t stop = len;
if (n_args >= 3) {
start = mp_get_index(type, len, args[2], true);
if (n_args >= 4) {
stop = mp_get_index(type, len, args[3], true);
}
}
for (size_t i = start; i < stop; i++) {
if (mp_obj_equal(items[i], value)) {
// Common sense says this cannot overflow small int
return MP_OBJ_NEW_SMALL_INT(i);
}
}
mp_raise_ValueError(translate("object not in sequence"));
}
mp_obj_t mp_seq_count_obj(const mp_obj_t *items, size_t len, mp_obj_t value) {
size_t count = 0;
for (size_t i = 0; i < len; i++) {
if (mp_obj_equal(items[i], value)) {
count++;
}
}
// Common sense says this cannot overflow small int
return MP_OBJ_NEW_SMALL_INT(count);
}