Commit 4c03b3a8 authored by Damien George's avatar Damien George
Browse files

py: Implement builtin reversed() function.

reversed function now implemented, and works for tuple, list, str, bytes
and user objects with __len__ and __getitem__.

Renamed mp_builtin_len to mp_obj_len to make it publically available (eg
for reversed).
parent 69c5fe1d
......@@ -284,17 +284,6 @@ STATIC mp_obj_t mp_builtin_iter(mp_obj_t o_in) {
MP_DEFINE_CONST_FUN_OBJ_1(mp_builtin_iter_obj, mp_builtin_iter);
STATIC mp_obj_t mp_builtin_len(mp_obj_t o_in) {
mp_obj_t len = mp_obj_len_maybe(o_in);
if (len == MP_OBJ_NULL) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "object of type '%s' has no len()", mp_obj_get_type_str(o_in)));
} else {
return len;
}
}
MP_DEFINE_CONST_FUN_OBJ_1(mp_builtin_len_obj, mp_builtin_len);
STATIC mp_obj_t mp_builtin_max(uint n_args, const mp_obj_t *args) {
if (n_args == 1) {
// given an iterable
......@@ -569,6 +558,7 @@ STATIC mp_obj_t mp_builtin_hasattr(mp_obj_t object_in, mp_obj_t attr_in) {
MP_DEFINE_CONST_FUN_OBJ_2(mp_builtin_hasattr_obj, mp_builtin_hasattr);
// These two are defined in terms of MicroPython API functions right away
// These are defined in terms of MicroPython API functions right away
MP_DEFINE_CONST_FUN_OBJ_1(mp_builtin_len_obj, mp_obj_len);
MP_DEFINE_CONST_FUN_OBJ_0(mp_builtin_globals_obj, mp_globals_get);
MP_DEFINE_CONST_FUN_OBJ_0(mp_builtin_locals_obj, mp_locals_get);
......@@ -26,6 +26,7 @@
mp_obj_t mp_builtin___import__(uint n_args, mp_obj_t *args);
mp_obj_t mp_builtin_open(uint n_args, const mp_obj_t *args);
mp_obj_t mp_builtin_len(mp_obj_t o);
MP_DECLARE_CONST_FUN_OBJ(mp_builtin___build_class___obj);
MP_DECLARE_CONST_FUN_OBJ(mp_builtin___import___obj);
......
......@@ -66,6 +66,7 @@ STATIC const mp_map_elem_t mp_builtin_object_table[] = {
{ MP_OBJ_NEW_QSTR(MP_QSTR_property), (mp_obj_t)&mp_type_property },
#endif
{ MP_OBJ_NEW_QSTR(MP_QSTR_range), (mp_obj_t)&mp_type_range },
{ MP_OBJ_NEW_QSTR(MP_QSTR_reversed), (mp_obj_t)&mp_type_reversed },
#if MICROPY_PY_BUILTINS_SET
{ MP_OBJ_NEW_QSTR(MP_QSTR_set), (mp_obj_t)&mp_type_set },
#endif
......
......@@ -360,6 +360,16 @@ uint mp_get_index(const mp_obj_type_t *type, mp_uint_t len, mp_obj_t index, bool
return i;
}
// will raise a TypeError if object has no length
mp_obj_t mp_obj_len(mp_obj_t o_in) {
mp_obj_t len = mp_obj_len_maybe(o_in);
if (len == MP_OBJ_NULL) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "object of type '%s' has no len()", mp_obj_get_type_str(o_in)));
} else {
return len;
}
}
// may return MP_OBJ_NULL
mp_obj_t mp_obj_len_maybe(mp_obj_t o_in) {
if (
......
......@@ -312,6 +312,7 @@ extern const mp_obj_type_t mp_type_classmethod;
extern const mp_obj_type_t mp_type_property;
extern const mp_obj_type_t mp_type_stringio;
extern const mp_obj_type_t mp_type_bytesio;
extern const mp_obj_type_t mp_type_reversed;
// Exceptions
extern const mp_obj_type_t mp_type_BaseException;
......@@ -424,6 +425,7 @@ void mp_obj_get_complex(mp_obj_t self_in, mp_float_t *real, mp_float_t *imag);
void mp_obj_get_array(mp_obj_t o, uint *len, mp_obj_t **items);
void mp_obj_get_array_fixed_n(mp_obj_t o, uint len, mp_obj_t **items);
uint mp_get_index(const mp_obj_type_t *type, mp_uint_t len, mp_obj_t index, bool is_slice);
mp_obj_t mp_obj_len(mp_obj_t o_in);
mp_obj_t mp_obj_len_maybe(mp_obj_t o_in); /* may return MP_OBJ_NULL */
mp_obj_t mp_obj_subscr(mp_obj_t base, mp_obj_t index, mp_obj_t val);
......
/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 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 "mpconfig.h"
#include "nlr.h"
#include "misc.h"
#include "qstr.h"
#include "obj.h"
#include "runtime.h"
typedef struct _mp_obj_reversed_t {
mp_obj_base_t base;
mp_obj_t seq; // sequence object that we are reversing
mp_uint_t cur_index; // current index, plus 1; 0=no more, 1=last one (index 0)
} mp_obj_reversed_t;
STATIC mp_obj_t reversed_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
mp_arg_check_num(n_args, n_kw, 1, 1, false);
mp_obj_reversed_t *o = m_new_obj(mp_obj_reversed_t);
o->base.type = &mp_type_reversed;
o->seq = args[0];
o->cur_index = mp_obj_get_int(mp_obj_len(args[0])); // start at the end of the sequence
return o;
}
STATIC mp_obj_t reversed_iternext(mp_obj_t self_in) {
assert(MP_OBJ_IS_TYPE(self_in, &mp_type_reversed));
mp_obj_reversed_t *self = self_in;
// "raise" stop iteration if we are at the end (the start) of the sequence
if (self->cur_index == 0) {
return MP_OBJ_STOP_ITERATION;
}
// pre-decrement and index sequence
self->cur_index -= 1;
return mp_obj_subscr(self->seq, MP_OBJ_NEW_SMALL_INT(self->cur_index), MP_OBJ_SENTINEL);
}
const mp_obj_type_t mp_type_reversed = {
{ &mp_type_type },
.name = MP_QSTR_reversed,
.make_new = reversed_make_new,
.getiter = mp_identity,
.iternext = reversed_iternext,
};
......@@ -72,6 +72,7 @@ PY_O_BASENAME = \
objnone.o \
objnamedtuple.o \
objrange.o \
objreversed.o \
objset.o \
objslice.o \
objstr.o \
......
......@@ -175,6 +175,7 @@ Q(print)
Q(range)
Q(read)
Q(repr)
Q(reversed)
Q(set)
Q(sorted)
Q(staticmethod)
......
# test the builtin reverse() function
# list
print(list(reversed([])))
print(list(reversed([1])))
print(list(reversed([1, 2, 3])))
# tuple
print(list(reversed(())))
print(list(reversed((1, 2, 3))))
# string
for c in reversed('ab'):
print(c)
# bytes
for b in reversed(b'1234'):
print(b)
# range
#for i in reversed(range(3)):
# print(i)
# user object
class A:
def __init__(self):
pass
def __len__(self):
return 3
def __getitem__(self, pos):
return pos + 1
for a in reversed(A()):
print(a)
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