1 /*
2 * This file is part of the MicroPython project, http://micropython.org/
3 *
4 * The MIT License (MIT)
5 *
6 * Copyright (c) 2013, 2014 Damien P. George
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 * THE SOFTWARE.
25 */
26
27 #include <stdlib.h>
28 #include <assert.h>
29
30 #include "py/runtime.h"
31
32 /******************************************************************************/
33 /* slice object */
34
35 #if MICROPY_PY_BUILTINS_SLICE
36
slice_print(const mp_print_t * print,mp_obj_t o_in,mp_print_kind_t kind)37 STATIC void slice_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t kind) {
38 (void)kind;
39 mp_obj_slice_t *o = MP_OBJ_TO_PTR(o_in);
40 mp_print_str(print, "slice(");
41 mp_obj_print_helper(print, o->start, PRINT_REPR);
42 mp_print_str(print, ", ");
43 mp_obj_print_helper(print, o->stop, PRINT_REPR);
44 mp_print_str(print, ", ");
45 mp_obj_print_helper(print, o->step, PRINT_REPR);
46 mp_print_str(print, ")");
47 }
48
49 #if MICROPY_PY_BUILTINS_SLICE_INDICES
slice_indices(mp_obj_t self_in,mp_obj_t length_obj)50 STATIC mp_obj_t slice_indices(mp_obj_t self_in, mp_obj_t length_obj) {
51 mp_int_t length = mp_obj_int_get_checked(length_obj);
52 mp_bound_slice_t bound_indices;
53 mp_obj_slice_indices(self_in, length, &bound_indices);
54
55 mp_obj_t results[3] = {
56 MP_OBJ_NEW_SMALL_INT(bound_indices.start),
57 MP_OBJ_NEW_SMALL_INT(bound_indices.stop),
58 MP_OBJ_NEW_SMALL_INT(bound_indices.step),
59 };
60 return mp_obj_new_tuple(3, results);
61 }
62 STATIC MP_DEFINE_CONST_FUN_OBJ_2(slice_indices_obj, slice_indices);
63 #endif
64
65 #if MICROPY_PY_BUILTINS_SLICE_ATTRS
slice_attr(mp_obj_t self_in,qstr attr,mp_obj_t * dest)66 STATIC void slice_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
67 if (dest[0] != MP_OBJ_NULL) {
68 // not load attribute
69 return;
70 }
71 mp_obj_slice_t *self = MP_OBJ_TO_PTR(self_in);
72
73 if (attr == MP_QSTR_start) {
74 dest[0] = self->start;
75 } else if (attr == MP_QSTR_stop) {
76 dest[0] = self->stop;
77 } else if (attr == MP_QSTR_step) {
78 dest[0] = self->step;
79 #if MICROPY_PY_BUILTINS_SLICE_INDICES
80 } else if (attr == MP_QSTR_indices) {
81 dest[0] = MP_OBJ_FROM_PTR(&slice_indices_obj);
82 dest[1] = self_in;
83 #endif
84 }
85 }
86 #endif
87
88 #if MICROPY_PY_BUILTINS_SLICE_INDICES && !MICROPY_PY_BUILTINS_SLICE_ATTRS
89 STATIC const mp_rom_map_elem_t slice_locals_dict_table[] = {
90 { MP_ROM_QSTR(MP_QSTR_indices), MP_ROM_PTR(&slice_indices_obj) },
91 };
92 STATIC MP_DEFINE_CONST_DICT(slice_locals_dict, slice_locals_dict_table);
93 #endif
94
95 const mp_obj_type_t mp_type_slice = {
96 { &mp_type_type },
97 .name = MP_QSTR_slice,
98 .print = slice_print,
99 #if MICROPY_PY_BUILTINS_SLICE_ATTRS
100 .attr = slice_attr,
101 #elif MICROPY_PY_BUILTINS_SLICE_INDICES
102 .locals_dict = (mp_obj_dict_t *)&slice_locals_dict,
103 #endif
104 };
105
mp_obj_new_slice(mp_obj_t ostart,mp_obj_t ostop,mp_obj_t ostep)106 mp_obj_t mp_obj_new_slice(mp_obj_t ostart, mp_obj_t ostop, mp_obj_t ostep) {
107 mp_obj_slice_t *o = m_new_obj(mp_obj_slice_t);
108 o->base.type = &mp_type_slice;
109 o->start = ostart;
110 o->stop = ostop;
111 o->step = ostep;
112 return MP_OBJ_FROM_PTR(o);
113 }
114
115 // Return the real index and step values for a slice when applied to a sequence of
116 // the given length, resolving missing components, negative values and values off
117 // the end of the sequence.
mp_obj_slice_indices(mp_obj_t self_in,mp_int_t length,mp_bound_slice_t * result)118 void mp_obj_slice_indices(mp_obj_t self_in, mp_int_t length, mp_bound_slice_t *result) {
119 mp_obj_slice_t *self = MP_OBJ_TO_PTR(self_in);
120 mp_int_t start, stop, step;
121
122 if (self->step == mp_const_none) {
123 step = 1;
124 } else {
125 step = mp_obj_get_int(self->step);
126 if (step == 0) {
127 mp_raise_ValueError(MP_ERROR_TEXT("slice step can't be zero"));
128 }
129 }
130
131 if (step > 0) {
132 // Positive step
133 if (self->start == mp_const_none) {
134 start = 0;
135 } else {
136 start = mp_obj_get_int(self->start);
137 if (start < 0) {
138 start += length;
139 }
140 start = MIN(length, MAX(start, 0));
141 }
142
143 if (self->stop == mp_const_none) {
144 stop = length;
145 } else {
146 stop = mp_obj_get_int(self->stop);
147 if (stop < 0) {
148 stop += length;
149 }
150 stop = MIN(length, MAX(stop, 0));
151 }
152 } else {
153 // Negative step
154 if (self->start == mp_const_none) {
155 start = length - 1;
156 } else {
157 start = mp_obj_get_int(self->start);
158 if (start < 0) {
159 start += length;
160 }
161 start = MIN(length - 1, MAX(start, -1));
162 }
163
164 if (self->stop == mp_const_none) {
165 stop = -1;
166 } else {
167 stop = mp_obj_get_int(self->stop);
168 if (stop < 0) {
169 stop += length;
170 }
171 stop = MIN(length - 1, MAX(stop, -1));
172 }
173 }
174
175 result->start = start;
176 result->stop = stop;
177 result->step = step;
178 }
179
180 #endif
181