circuitpython/py/objgetitemiter.c
2014-01-25 00:17:36 +00:00

54 lines
1.6 KiB
C

#include <stdlib.h>
#include <stdint.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 = rt_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_IS_TYPE(nlr.ret_val, &exception_type) && mp_obj_exception_get_type(nlr.ret_val) == MP_QSTR_StopIteration) {
// return mp_const_stop_iteration instead of raising StopIteration
return mp_const_stop_iteration;
} else {
// re-raise exception
nlr_jump(nlr.ret_val);
}
}
}
static const mp_obj_type_t it_type = {
{ &mp_const_type },
"iterator",
.iternext = it_iternext
};
// args are those returned from rt_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;
}