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 
29 #include "py/runtime.h"
30 
31 // this is a wrapper object that turns something that has a __getitem__ method into an iterator
32 
33 typedef struct _mp_obj_getitem_iter_t {
34     mp_obj_base_t base;
35     mp_obj_t args[3];
36 } mp_obj_getitem_iter_t;
37 
it_iternext(mp_obj_t self_in)38 STATIC mp_obj_t it_iternext(mp_obj_t self_in) {
39     mp_obj_getitem_iter_t *self = MP_OBJ_TO_PTR(self_in);
40     nlr_buf_t nlr;
41     if (nlr_push(&nlr) == 0) {
42         // try to get next item
43         mp_obj_t value = mp_call_method_n_kw(1, 0, self->args);
44         self->args[2] = MP_OBJ_NEW_SMALL_INT(MP_OBJ_SMALL_INT_VALUE(self->args[2]) + 1);
45         nlr_pop();
46         return value;
47     } else {
48         // an exception was raised
49         mp_obj_type_t *t = (mp_obj_type_t *)((mp_obj_base_t *)nlr.ret_val)->type;
50         if (t == &mp_type_StopIteration || t == &mp_type_IndexError) {
51             return MP_OBJ_STOP_ITERATION;
52         } else {
53             // re-raise exception
54             nlr_jump(nlr.ret_val);
55         }
56     }
57 }
58 
59 STATIC const mp_obj_type_t mp_type_it = {
60     { &mp_type_type },
61     .name = MP_QSTR_iterator,
62     .getiter = mp_identity_getiter,
63     .iternext = it_iternext,
64 };
65 
66 // args are those returned from mp_load_method_maybe (ie either an attribute or a method)
mp_obj_new_getitem_iter(mp_obj_t * args,mp_obj_iter_buf_t * iter_buf)67 mp_obj_t mp_obj_new_getitem_iter(mp_obj_t *args, mp_obj_iter_buf_t *iter_buf) {
68     assert(sizeof(mp_obj_getitem_iter_t) <= sizeof(mp_obj_iter_buf_t));
69     mp_obj_getitem_iter_t *o = (mp_obj_getitem_iter_t *)iter_buf;
70     o->base.type = &mp_type_it;
71     o->args[0] = args[0];
72     o->args[1] = args[1];
73     o->args[2] = MP_OBJ_NEW_SMALL_INT(0);
74     return MP_OBJ_FROM_PTR(o);
75 }
76