circuitpython/py/objslice.c

256 lines
7.8 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
*
* 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 <stdlib.h>
#include <assert.h>
#include "py/obj.h"
#include "py/runtime.h"
#include "py/runtime0.h"
#include "supervisor/shared/translate.h"
/******************************************************************************/
/* slice object */
#if MICROPY_PY_BUILTINS_SLICE
// TODO: This implements only variant of slice with 2 integer args only.
// CPython supports 3rd arg (step), plus args can be arbitrary Python objects.
typedef struct _mp_obj_slice_t {
mp_obj_base_t base;
mp_obj_t start;
mp_obj_t stop;
mp_obj_t step;
} mp_obj_slice_t;
STATIC void slice_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t kind) {
(void)kind;
mp_obj_slice_t *o = MP_OBJ_TO_PTR(o_in);
mp_print_str(print, "slice(");
mp_obj_print_helper(print, o->start, PRINT_REPR);
mp_print_str(print, ", ");
mp_obj_print_helper(print, o->stop, PRINT_REPR);
mp_print_str(print, ", ");
mp_obj_print_helper(print, o->step, PRINT_REPR);
mp_print_str(print, ")");
}
#if MICROPY_PY_BUILTINS_SLICE_ATTRS
STATIC mp_obj_t slice_indices(mp_obj_t self_in, mp_obj_t length_obj) {
mp_obj_slice_t *self = MP_OBJ_TO_PTR(self_in);
if (!MP_OBJ_IS_SMALL_INT(length_obj)) {
mp_raise_TypeError(translate("Length must be an int"));
}
int length = MP_OBJ_SMALL_INT_VALUE(length_obj);
if (length < 0) {
mp_raise_ValueError(translate("Length must be non-negative"));
}
mp_obj_t indices[3] = {MP_OBJ_NEW_SMALL_INT(0), length_obj, MP_OBJ_NEW_SMALL_INT(1)};
mp_obj_t slice[2] = {self->start, self->stop};
int step = 1;
if (self->step != mp_const_none) {
indices[2] = self->step;
step = MP_OBJ_SMALL_INT_VALUE(self->step);
if (step < 0) {
indices[0] = MP_OBJ_NEW_SMALL_INT(length - 1);
indices[1] = MP_OBJ_NEW_SMALL_INT(-1);
}
if (step == 0) {
mp_raise_ValueError(translate("slice step cannot be zero"));
}
}
for (int i = 0; i < 2; i++) {
if (slice[i] == mp_const_none) {
continue;
}
int value = MP_OBJ_SMALL_INT_VALUE(slice[i]);
if (value < 0) {
value += length;
}
if (value < 0) {
if (step > 0) {
value = 0;
} else if (step < 0) {
value = -1;
}
} else if (value > length) {
value = length;
}
indices[i] = MP_OBJ_NEW_SMALL_INT(value);
}
mp_obj_t tuple = mp_obj_new_tuple(3, indices);
return tuple;
}
MP_DEFINE_CONST_FUN_OBJ_2(slice_indices_obj, slice_indices);
STATIC void slice_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
if (dest[0] != MP_OBJ_NULL) {
// not load attribute
return;
}
mp_obj_slice_t *self = MP_OBJ_TO_PTR(self_in);
if (attr == MP_QSTR_start) {
dest[0] = self->start;
} else if (attr == MP_QSTR_stop) {
dest[0] = self->stop;
} else if (attr == MP_QSTR_step) {
dest[0] = self->step;
} else if (attr == MP_QSTR_indices) {
mp_convert_member_lookup(self_in, self->base.type, (mp_obj_t) &slice_indices_obj, dest);
}
}
STATIC mp_obj_t slice_make_new(const mp_obj_type_t *type,
size_t n_args, const mp_obj_t *args, mp_map_t *kw_args);
#endif
const mp_obj_type_t mp_type_slice = {
{ &mp_type_type },
.name = MP_QSTR_slice,
.print = slice_print,
#if MICROPY_PY_BUILTINS_SLICE_ATTRS
.make_new = slice_make_new,
.attr = slice_attr,
#endif
};
mp_obj_t mp_obj_new_slice(mp_obj_t ostart, mp_obj_t ostop, mp_obj_t ostep) {
mp_obj_slice_t *o = m_new_obj(mp_obj_slice_t);
o->base.type = &mp_type_slice;
o->start = ostart;
o->stop = ostop;
o->step = ostep;
return MP_OBJ_FROM_PTR(o);
}
// Return the real index and step values for a slice when applied to a sequence of
// the given length, resolving missing components, negative values and values off
// the end of the sequence.
void mp_obj_slice_indices(mp_obj_t self_in, mp_int_t length, mp_bound_slice_t *result) {
mp_obj_slice_t *self = MP_OBJ_TO_PTR(self_in);
mp_int_t start, stop, step;
if (self->step == mp_const_none) {
step = 1;
} else {
step = mp_obj_get_int(self->step);
if (step == 0) {
mp_raise_ValueError(translate("slice step cannot be zero"));
}
}
if (step > 0) {
// Positive step
if (self->start == mp_const_none) {
start = 0;
} else {
start = mp_obj_get_int(self->start);
if (start < 0) {
start += length;
}
start = MIN(length, MAX(start, 0));
}
if (self->stop == mp_const_none) {
stop = length;
} else {
stop = mp_obj_get_int(self->stop);
if (stop < 0) {
stop += length;
}
stop = MIN(length, MAX(stop, 0));
}
} else {
// Negative step
if (self->start == mp_const_none) {
start = length - 1;
} else {
start = mp_obj_get_int(self->start);
if (start < 0) {
start += length;
}
start = MIN(length - 1, MAX(start, -1));
}
if (self->stop == mp_const_none) {
stop = -1;
} else {
stop = mp_obj_get_int(self->stop);
if (stop < 0) {
stop += length;
}
stop = MIN(length - 1, MAX(stop, -1));
}
}
result->start = start;
result->stop = stop;
result->step = step;
}
#if MICROPY_PY_BUILTINS_SLICE_ATTRS
STATIC mp_obj_t slice_make_new(const mp_obj_type_t *type,
size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
if (type != &mp_type_slice) {
mp_raise_NotImplementedError(translate("Cannot subclass slice"));
}
// check number of arguments
mp_arg_check_num(n_args, kw_args, 1, 3, false);
// 1st argument is the pin
mp_obj_t start = mp_const_none;
mp_obj_t stop = mp_const_none;
mp_obj_t step = mp_const_none;
if (n_args == 1) {
stop = args[0];
} else {
start = args[0];
stop = args[1];
if (n_args == 3) {
step = args[2];
}
}
return mp_obj_new_slice(start, stop, step);
}
#endif
void mp_obj_slice_get(mp_obj_t self_in, mp_obj_t *start, mp_obj_t *stop, mp_obj_t *step) {
assert(MP_OBJ_IS_TYPE(self_in, &mp_type_slice));
mp_obj_slice_t *self = MP_OBJ_TO_PTR(self_in);
*start = self->start;
*stop = self->stop;
*step = self->step;
}
#endif