circuitpython/py/objgetitemiter.c

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#include <stdlib.h>
#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "runtime.h"
// this is a wrapper object that is turns something that has a __getitem__ method into an iterator
typedef struct _mp_obj_getitem_iter_t {
mp_obj_base_t base;
mp_obj_t args[3];
} mp_obj_getitem_iter_t;
STATIC mp_obj_t it_iternext(mp_obj_t self_in) {
mp_obj_getitem_iter_t *self = self_in;
nlr_buf_t nlr;
if (nlr_push(&nlr) == 0) {
// try to get next item
mp_obj_t value = mp_call_method_n_kw(1, 0, self->args);
self->args[2] = MP_OBJ_NEW_SMALL_INT(MP_OBJ_SMALL_INT_VALUE(self->args[2]) + 1);
nlr_pop();
return value;
} else {
// an exception was raised
if (mp_obj_get_type(nlr.ret_val) == &mp_type_StopIteration) {
// return MP_OBJ_STOP_ITERATION instead of raising StopIteration
return MP_OBJ_STOP_ITERATION;
} else {
// re-raise exception
nlr_raise(nlr.ret_val);
}
}
}
STATIC const mp_obj_type_t it_type = {
{ &mp_type_type },
.name = MP_QSTR_iterator,
.getiter = mp_identity,
.iternext = it_iternext
};
// args are those returned from mp_load_method_maybe (ie either an attribute or a method)
mp_obj_t mp_obj_new_getitem_iter(mp_obj_t *args) {
mp_obj_getitem_iter_t *o = m_new_obj(mp_obj_getitem_iter_t);
o->base.type = &it_type;
o->args[0] = args[0];
o->args[1] = args[1];
o->args[2] = MP_OBJ_NEW_SMALL_INT(0);
return o;
}