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circuitpython/py/objstr.c

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#include <stdlib.h>
#include <stdint.h>
#include <stdarg.h>
#include <string.h>
#include <assert.h>
#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "runtime0.h"
#include "runtime.h"
typedef struct _mp_obj_str_t {
mp_obj_base_t base;
machine_uint_t hash : 16; // XXX here we assume the hash size is 16 bits (it is at the moment; see qstr.c)
machine_uint_t len : 16; // len == number of bytes used in data, alloc = len + 1 because (at the moment) we also append a null byte
byte data[];
} mp_obj_str_t;
// use this macro to extract the string hash
#define GET_STR_HASH(str_obj_in, str_hash) uint str_hash; if (MP_OBJ_IS_QSTR(str_obj_in)) { str_hash = qstr_hash(MP_OBJ_QSTR_VALUE(str_obj_in)); } else { str_hash = ((mp_obj_str_t*)str_obj_in)->hash; }
// use this macro to extract the string length
#define GET_STR_LEN(str_obj_in, str_len) uint str_len; if (MP_OBJ_IS_QSTR(str_obj_in)) { str_len = qstr_len(MP_OBJ_QSTR_VALUE(str_obj_in)); } else { str_len = ((mp_obj_str_t*)str_obj_in)->len; }
// use this macro to extract the string data and length
#define GET_STR_DATA_LEN(str_obj_in, str_data, str_len) const byte *str_data; uint str_len; if (MP_OBJ_IS_QSTR(str_obj_in)) { str_data = qstr_data(MP_OBJ_QSTR_VALUE(str_obj_in), &str_len); } else { str_len = ((mp_obj_str_t*)str_obj_in)->len; str_data = ((mp_obj_str_t*)str_obj_in)->data; }
static mp_obj_t mp_obj_new_str_iterator(mp_obj_t str, int cur);
/******************************************************************************/
/* str */
void str_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
GET_STR_DATA_LEN(self_in, str_data, str_len);
if (kind == PRINT_STR) {
print(env, "%.*s", str_len, str_data);
} else {
// TODO need to escape chars etc
print(env, "'%.*s'", str_len, str_data);
}
}
// like strstr but with specified length and allows \0 bytes
// TODO replace with something more efficient/standard
static const byte *find_subbytes(const byte *haystack, uint hlen, const byte *needle, uint nlen) {
if (hlen >= nlen) {
for (uint i = 0; i <= hlen - nlen; i++) {
bool found = true;
for (uint j = 0; j < nlen; j++) {
if (haystack[i + j] != needle[j]) {
found = false;
break;
}
}
if (found) {
return haystack + i;
}
}
}
return NULL;
}
mp_obj_t str_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
GET_STR_DATA_LEN(lhs_in, lhs_data, lhs_len);
switch (op) {
case RT_BINARY_OP_SUBSCR:
// TODO: need predicate to check for int-like type (bools are such for example)
// ["no", "yes"][1 == 2] is common idiom
if (MP_OBJ_IS_SMALL_INT(rhs_in)) {
uint index = mp_get_index(mp_obj_get_type(lhs_in), lhs_len, rhs_in);
return mp_obj_new_str(lhs_data + index, 1, true);
#if MICROPY_ENABLE_SLICE
} else if (MP_OBJ_IS_TYPE(rhs_in, &slice_type)) {
machine_int_t start, stop, step;
mp_obj_slice_get(rhs_in, &start, &stop, &step);
assert(step == 1);
if (start < 0) {
start = lhs_len + start;
if (start < 0) {
start = 0;
}
} else if (start > lhs_len) {
start = lhs_len;
}
if (stop <= 0) {
stop = lhs_len + stop;
// CPython returns empty string in such case
if (stop < 0) {
stop = start;
}
} else if (stop > lhs_len) {
stop = lhs_len;
}
return mp_obj_new_str(lhs_data + start, stop - start, false);
#endif
} else {
// Message doesn't match CPython, but we don't have so much bytes as they
// to spend them on verbose wording
nlr_jump(mp_obj_new_exception_msg(MP_QSTR_TypeError, "index must be int"));
}
case RT_BINARY_OP_ADD:
case RT_BINARY_OP_INPLACE_ADD:
if (MP_OBJ_IS_STR(rhs_in)) {
// add 2 strings
GET_STR_DATA_LEN(rhs_in, rhs_data, rhs_len);
int alloc_len = lhs_len + rhs_len;
/* code for making qstr
byte *q_ptr;
byte *val = qstr_build_start(alloc_len, &q_ptr);
memcpy(val, lhs_data, lhs_len);
memcpy(val + lhs_len, rhs_data, rhs_len);
return MP_OBJ_NEW_QSTR(qstr_build_end(q_ptr));
*/
// code for non-qstr
byte *data;
mp_obj_t s = mp_obj_str_builder_start(alloc_len, &data);
memcpy(data, lhs_data, lhs_len);
memcpy(data + lhs_len, rhs_data, rhs_len);
return mp_obj_str_builder_end(s);
}
break;
case RT_COMPARE_OP_IN:
case RT_COMPARE_OP_NOT_IN:
/* NOTE `a in b` is `b.__contains__(a)` */
if (MP_OBJ_IS_STR(rhs_in)) {
GET_STR_DATA_LEN(rhs_in, rhs_data, rhs_len);
return MP_BOOL((op == RT_COMPARE_OP_IN) ^ (find_subbytes(lhs_data, lhs_len, rhs_data, rhs_len) == NULL));
}
break;
case RT_BINARY_OP_MULTIPLY:
{
if (!MP_OBJ_IS_SMALL_INT(rhs_in)) {
return NULL;
}
int n = MP_OBJ_SMALL_INT_VALUE(rhs_in);
byte *data;
mp_obj_t s = mp_obj_str_builder_start(lhs_len * n, &data);
mp_seq_multiply(lhs_data, sizeof(*lhs_data), lhs_len, n, data);
return mp_obj_str_builder_end(s);
}
}
return MP_OBJ_NULL; // op not supported
}
static mp_obj_t str_getiter(mp_obj_t o_in) {
return mp_obj_new_str_iterator(o_in, 0);
}
mp_obj_t str_join(mp_obj_t self_in, mp_obj_t arg) {
assert(MP_OBJ_IS_STR(self_in));
// get separation string
GET_STR_DATA_LEN(self_in, sep_str, sep_len);
// process args
uint seq_len;
mp_obj_t *seq_items;
if (MP_OBJ_IS_TYPE(arg, &tuple_type)) {
mp_obj_tuple_get(arg, &seq_len, &seq_items);
} else if (MP_OBJ_IS_TYPE(arg, &list_type)) {
mp_obj_list_get(arg, &seq_len, &seq_items);
} else {
goto bad_arg;
}
// count required length
int required_len = 0;
for (int i = 0; i < seq_len; i++) {
if (!MP_OBJ_IS_STR(seq_items[i])) {
goto bad_arg;
}
if (i > 0) {
required_len += sep_len;
}
GET_STR_LEN(seq_items[i], l);
required_len += l;
}
// make joined string
byte *data;
mp_obj_t joined_str = mp_obj_str_builder_start(required_len, &data);
for (int i = 0; i < seq_len; i++) {
if (i > 0) {
memcpy(data, sep_str, sep_len);
data += sep_len;
}
GET_STR_DATA_LEN(seq_items[i], s, l);
memcpy(data, s, l);
data += l;
}
// return joined string
return mp_obj_str_builder_end(joined_str);
bad_arg:
nlr_jump(mp_obj_new_exception_msg(MP_QSTR_TypeError, "?str.join expecting a list of str's"));
}
#define is_ws(c) ((c) == ' ' || (c) == '\t')
static mp_obj_t str_split(uint n_args, const mp_obj_t *args) {
int splits = -1;
mp_obj_t sep = mp_const_none;
if (n_args > 1) {
sep = args[1];
if (n_args > 2) {
splits = MP_OBJ_SMALL_INT_VALUE(args[2]);
}
}
assert(sep == mp_const_none);
(void)sep; // unused; to hush compiler warning
mp_obj_t res = mp_obj_new_list(0, NULL);
GET_STR_DATA_LEN(args[0], s, len);
const byte *top = s + len;
const byte *start;
// Initial whitespace is not counted as split, so we pre-do it
while (s < top && is_ws(*s)) s++;
while (s < top && splits != 0) {
start = s;
while (s < top && !is_ws(*s)) s++;
rt_list_append(res, mp_obj_new_str(start, s - start, false));
if (s >= top) {
break;
}
while (s < top && is_ws(*s)) s++;
if (splits > 0) {
splits--;
}
}
if (s < top) {
rt_list_append(res, mp_obj_new_str(s, top - s, false));
}
return res;
}
static mp_obj_t str_find(uint n_args, const mp_obj_t *args) {
assert(2 <= n_args && n_args <= 4);
assert(MP_OBJ_IS_STR(args[0]));
assert(MP_OBJ_IS_STR(args[1]));
GET_STR_DATA_LEN(args[0], haystack, haystack_len);
GET_STR_DATA_LEN(args[1], needle, needle_len);
size_t start = 0;
size_t end = haystack_len;
/* TODO use a non-exception-throwing mp_get_index */
if (n_args >= 3 && args[2] != mp_const_none) {
start = mp_get_index(&str_type, haystack_len, args[2]);
}
if (n_args >= 4 && args[3] != mp_const_none) {
end = mp_get_index(&str_type, haystack_len, args[3]);
}
const byte *p = find_subbytes(haystack + start, haystack_len - start, needle, needle_len);
if (p == NULL) {
// not found
return MP_OBJ_NEW_SMALL_INT(-1);
} else {
// found
machine_int_t pos = p - haystack;
if (pos + needle_len > end) {
pos = -1;
}
return MP_OBJ_NEW_SMALL_INT(pos);
}
}
static bool chr_in_str(const byte* const str, const size_t str_len, int c) {
for (size_t i = 0; i < str_len; i++) {
if (str[i] == c) {
return true;
}
}
return false;
}
mp_obj_t str_strip(uint n_args, const mp_obj_t *args) {
assert(1 <= n_args && n_args <= 2);
assert(MP_OBJ_IS_STR(args[0]));
const byte *chars_to_del;
uint chars_to_del_len;
static const byte whitespace[] = " \t\n\r\v\f";
if (n_args == 1) {
chars_to_del = whitespace;
chars_to_del_len = sizeof(whitespace);
} else {
assert(MP_OBJ_IS_STR(args[1]));
GET_STR_DATA_LEN(args[1], s, l);
chars_to_del = s;
chars_to_del_len = l;
}
GET_STR_DATA_LEN(args[0], orig_str, orig_str_len);
size_t first_good_char_pos = 0;
bool first_good_char_pos_set = false;
size_t last_good_char_pos = 0;
for (size_t i = 0; i < orig_str_len; i++) {
if (!chr_in_str(chars_to_del, chars_to_del_len, orig_str[i])) {
last_good_char_pos = i;
if (!first_good_char_pos_set) {
first_good_char_pos = i;
first_good_char_pos_set = true;
}
}
}
if (first_good_char_pos == 0 && last_good_char_pos == 0) {
// string is all whitespace, return ''
return MP_OBJ_NEW_QSTR(MP_QSTR_);
}
assert(last_good_char_pos >= first_good_char_pos);
//+1 to accomodate the last character
size_t stripped_len = last_good_char_pos - first_good_char_pos + 1;
return mp_obj_new_str(orig_str + first_good_char_pos, stripped_len, false);
}
mp_obj_t str_format(uint n_args, const mp_obj_t *args) {
assert(MP_OBJ_IS_STR(args[0]));
GET_STR_DATA_LEN(args[0], str, len);
int arg_i = 1;
vstr_t *vstr = vstr_new();
for (const byte *top = str + len; str < top; str++) {
if (*str == '{') {
str++;
if (str < top && *str == '{') {
vstr_add_char(vstr, '{');
} else {
while (str < top && *str != '}') str++;
if (arg_i >= n_args) {
nlr_jump(mp_obj_new_exception_msg(MP_QSTR_IndexError, "tuple index out of range"));
}
// TODO: may be PRINT_REPR depending on formatting code
mp_obj_print_helper((void (*)(void*, const char*, ...))vstr_printf, vstr, args[arg_i], PRINT_STR);
arg_i++;
}
} else {
vstr_add_char(vstr, *str);
}
}
mp_obj_t s = mp_obj_new_str((byte*)vstr->buf, vstr->len, false);
vstr_free(vstr);
return s;
}
static MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_find_obj, 2, 4, str_find);
static MP_DEFINE_CONST_FUN_OBJ_2(str_join_obj, str_join);
static MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_split_obj, 1, 3, str_split);
static MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_strip_obj, 1, 2, str_strip);
static MP_DEFINE_CONST_FUN_OBJ_VAR(str_format_obj, 1, str_format);
static const mp_method_t str_type_methods[] = {
{ "find", &str_find_obj },
{ "join", &str_join_obj },
{ "split", &str_split_obj },
{ "strip", &str_strip_obj },
{ "format", &str_format_obj },
{ NULL, NULL }, // end-of-list sentinel
};
const mp_obj_type_t str_type = {
{ &mp_const_type },
"str",
.print = str_print,
.binary_op = str_binary_op,
.getiter = str_getiter,
.methods = str_type_methods,
};
mp_obj_t mp_obj_str_builder_start(uint len, byte **data) {
mp_obj_str_t *o = m_new_obj_var(mp_obj_str_t, byte, len + 1);
o->base.type = &str_type;
o->len = len;
*data = o->data;
return o;
}
mp_obj_t mp_obj_str_builder_end(mp_obj_t o_in) {
assert(MP_OBJ_IS_STR(o_in));
mp_obj_str_t *o = o_in;
o->hash = qstr_compute_hash(o->data, o->len);
o->data[o->len] = '\0'; // for now we add null for compatibility with C ASCIIZ strings
return o;
}
mp_obj_t mp_obj_new_str(const byte* data, uint len, bool make_qstr_if_not_already) {
qstr q = qstr_find_strn(data, len);
if (q != MP_QSTR_NULL) {
// qstr with this data already exists
return MP_OBJ_NEW_QSTR(q);
} else if (make_qstr_if_not_already) {
// no existing qstr, make a new one
return MP_OBJ_NEW_QSTR(qstr_from_strn((const char*)data, len));
} else {
// no existing qstr, don't make one
mp_obj_str_t *o = m_new_obj_var(mp_obj_str_t, byte, len + 1);
o->base.type = &str_type;
o->hash = qstr_compute_hash(data, len);
o->len = len;
memcpy(o->data, data, len * sizeof(byte));
o->data[len] = '\0'; // for now we add null for compatibility with C ASCIIZ strings
return o;
}
}
bool mp_obj_str_equal(mp_obj_t s1, mp_obj_t s2) {
if (MP_OBJ_IS_QSTR(s1) && MP_OBJ_IS_QSTR(s2)) {
return s1 == s2;
} else {
GET_STR_HASH(s1, h1);
GET_STR_HASH(s2, h2);
if (h1 != h2) {
return false;
}
GET_STR_DATA_LEN(s1, d1, l1);
GET_STR_DATA_LEN(s2, d2, l2);
if (l1 != l2) {
return false;
}
return strncmp((const char*)d1, (const char*)d2, l1) == 0;
}
}
uint mp_obj_str_get_hash(mp_obj_t self_in) {
if (MP_OBJ_IS_STR(self_in)) {
GET_STR_HASH(self_in, h);
return h;
} else {
nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_TypeError, "Can't convert '%s' object to str implicitly",
mp_obj_get_type_str(self_in)));
}
}
uint mp_obj_str_get_len(mp_obj_t self_in) {
if (MP_OBJ_IS_STR(self_in)) {
GET_STR_LEN(self_in, l);
return l;
} else {
nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_TypeError, "Can't convert '%s' object to str implicitly",
mp_obj_get_type_str(self_in)));
}
}
// only use this function if you need the str data to be zero terminated
// at the moment all strings are zero terminated to help with C ASCIIZ compatibility
const char *mp_obj_str_get_str(mp_obj_t self_in) {
if (MP_OBJ_IS_STR(self_in)) {
GET_STR_DATA_LEN(self_in, s, l);
(void)l; // len unused
return (const char*)s;
} else {
nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_TypeError, "Can't convert '%s' object to str implicitly",
mp_obj_get_type_str(self_in)));
}
}
const byte *mp_obj_str_get_data(mp_obj_t self_in, uint *len) {
if (MP_OBJ_IS_STR(self_in)) {
GET_STR_DATA_LEN(self_in, s, l);
*len = l;
return s;
} else {
nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_TypeError, "Can't convert '%s' object to str implicitly",
mp_obj_get_type_str(self_in)));
}
}
/******************************************************************************/
/* str iterator */
typedef struct _mp_obj_str_it_t {
mp_obj_base_t base;
mp_obj_t str;
machine_uint_t cur;
} mp_obj_str_it_t;
mp_obj_t str_it_iternext(mp_obj_t self_in) {
mp_obj_str_it_t *self = self_in;
GET_STR_DATA_LEN(self->str, str, len);
if (self->cur < len) {
mp_obj_t o_out = mp_obj_new_str(str + self->cur, 1, true);
self->cur += 1;
return o_out;
} else {
return mp_const_stop_iteration;
}
}
static const mp_obj_type_t str_it_type = {
{ &mp_const_type },
"str_iterator",
.iternext = str_it_iternext,
};
mp_obj_t mp_obj_new_str_iterator(mp_obj_t str, int cur) {
mp_obj_str_it_t *o = m_new_obj(mp_obj_str_it_t);
o->base.type = &str_it_type;
o->str = str;
o->cur = cur;
return o;
}
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