micropython/py/objslice.c

181 wiersze
5.7 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/runtime.h"
/******************************************************************************/
/* slice object */
#if MICROPY_PY_BUILTINS_SLICE
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_INDICES
STATIC mp_obj_t slice_indices(mp_obj_t self_in, mp_obj_t length_obj) {
mp_int_t length = mp_obj_int_get_checked(length_obj);
mp_bound_slice_t bound_indices;
mp_obj_slice_indices(self_in, length, &bound_indices);
mp_obj_t results[3] = {
MP_OBJ_NEW_SMALL_INT(bound_indices.start),
MP_OBJ_NEW_SMALL_INT(bound_indices.stop),
MP_OBJ_NEW_SMALL_INT(bound_indices.step),
};
return mp_obj_new_tuple(3, results);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(slice_indices_obj, slice_indices);
#endif
#if MICROPY_PY_BUILTINS_SLICE_ATTRS
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;
#if MICROPY_PY_BUILTINS_SLICE_INDICES
} else if (attr == MP_QSTR_indices) {
dest[0] = MP_OBJ_FROM_PTR(&slice_indices_obj);
dest[1] = self_in;
#endif
}
}
#endif
#if MICROPY_PY_BUILTINS_SLICE_INDICES && !MICROPY_PY_BUILTINS_SLICE_ATTRS
STATIC const mp_rom_map_elem_t slice_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_indices), MP_ROM_PTR(&slice_indices_obj) },
};
STATIC MP_DEFINE_CONST_DICT(slice_locals_dict, slice_locals_dict_table);
#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
.attr = slice_attr,
#elif MICROPY_PY_BUILTINS_SLICE_INDICES
.locals_dict = (mp_obj_dict_t *)&slice_locals_dict,
#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(MP_ERROR_TEXT("slice step can't 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;
}
#endif