circuitpython/py/sequence.c
2014-02-02 08:58:16 +02:00

94 lines
2.5 KiB
C

#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <assert.h>
#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "map.h"
#include "runtime0.h"
#include "runtime.h"
// Helpers for sequence types
#define SWAP(type, var1, var2) { type t = var2; var2 = var1; var1 = t; }
// Implements backend of sequence * integer operation. Assumes elements are
// memory-adjacent in sequence.
void mp_seq_multiply(const void *items, uint item_sz, uint len, uint times, void *dest) {
for (int i = 0; i < times; i++) {
uint copy_sz = item_sz * len;
memcpy(dest, items, copy_sz);
dest = (char*)dest + copy_sz;
}
}
bool m_seq_get_fast_slice_indexes(machine_uint_t len, mp_obj_t slice, machine_uint_t *begin, machine_uint_t *end) {
machine_int_t start, stop, step;
mp_obj_slice_get(slice, &start, &stop, &step);
if (step != 1) {
return false;
}
// Unlike subscription, out-of-bounds slice indexes are never error
if (start < 0) {
start = len + start;
if (start < 0) {
start = 0;
}
} else if (start > len) {
start = len;
}
if (stop <= 0) {
stop = len + stop;
// CPython returns empty sequence in such case
if (stop < 0) {
stop = start;
}
} else if (stop > len) {
stop = len;
}
*begin = start;
*end = stop;
return true;
}
// Special-case comparison function for sequences of bytes
// Don't pass RT_BINARY_OP_NOT_EQUAL here
bool mp_seq_cmp_bytes(int op, const byte *data1, uint len1, const byte *data2, uint len2) {
// Let's deal only with > & >=
if (op == RT_BINARY_OP_LESS || op == RT_BINARY_OP_LESS_EQUAL) {
SWAP(const byte*, data1, data2);
SWAP(uint, len1, len2);
if (op == RT_BINARY_OP_LESS) {
op = RT_BINARY_OP_MORE;
} else {
op = RT_BINARY_OP_MORE_EQUAL;
}
}
uint min_len = len1 < len2 ? len1 : len2;
int res = memcmp(data1, data2, min_len);
if (res < 0) {
return false;
}
if (res > 0) {
return true;
}
// If we had tie in the last element...
// ... and we have lists of different lengths...
if (len1 != len2) {
if (len1 < len2) {
// ... then longer list length wins (we deal only with >)
return false;
}
} else if (op == RT_BINARY_OP_MORE) {
// Otherwise, if we have strict relation, equality means failure
return false;
}
return true;
}