diff options
Diffstat (limited to 'py/sequence.c')
| -rw-r--r-- | py/sequence.c | 38 |
1 files changed, 30 insertions, 8 deletions
diff --git a/py/sequence.c b/py/sequence.c index 8418f1ef67..c940d9f69f 100644 --- a/py/sequence.c +++ b/py/sequence.c @@ -51,15 +51,10 @@ void mp_seq_multiply(const void *items, uint item_sz, uint len, uint times, void } } -bool mp_seq_get_fast_slice_indexes(machine_uint_t len, mp_obj_t slice, machine_uint_t *begin, machine_uint_t *end) { +bool mp_seq_get_fast_slice_indexes(machine_uint_t len, mp_obj_t slice, mp_bound_slice_t *indexes) { mp_obj_t ostart, ostop, ostep; machine_int_t start, stop; mp_obj_slice_get(slice, &ostart, &ostop, &ostep); - if (ostep != mp_const_none && ostep != MP_OBJ_NEW_SMALL_INT(1)) { - nlr_raise(mp_obj_new_exception_msg(&mp_type_NotImplementedError, - "Only slices with step=1 (aka None) are supported")); - return false; - } if (ostart == mp_const_none) { start = 0; @@ -96,11 +91,38 @@ bool mp_seq_get_fast_slice_indexes(machine_uint_t len, mp_obj_t slice, machine_u stop = start; } - *begin = start; - *end = stop; + indexes->start = start; + indexes->stop = stop; + + if (ostep != mp_const_none && ostep != MP_OBJ_NEW_SMALL_INT(1)) { + indexes->step = MP_OBJ_SMALL_INT_VALUE(ostep); + return false; + } + indexes->step = 1; return true; } +mp_obj_t mp_seq_extract_slice(uint len, const mp_obj_t *seq, mp_bound_slice_t *indexes) { + machine_int_t start = indexes->start, stop = indexes->stop; + machine_int_t step = indexes->step; + + mp_obj_t res = mp_obj_new_list(0, NULL); + + if (step < 0) { + stop--; + while (start <= stop) { + mp_obj_list_append(res, seq[stop]); + stop += step; + } + } else { + while (start < stop) { + mp_obj_list_append(res, seq[start]); + start += step; + } + } + return res; +} + // Special-case comparison function for sequences of bytes // Don't pass MP_BINARY_OP_NOT_EQUAL here bool mp_seq_cmp_bytes(int op, const byte *data1, uint len1, const byte *data2, uint len2) { |