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 "obj.h"
#include "runtime0.h"
#include "runtime.h"
typedef struct _mp_obj_str_t {
mp_obj_base_t base;
qstr qstr;
} mp_obj_str_t;
void str_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in) {
mp_obj_str_t *self = self_in;
// TODO need to escape chars etc
print(env, "'%s'", qstr_str(self->qstr));
}
mp_obj_t str_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
mp_obj_str_t *lhs = lhs_in;
const char *lhs_str = qstr_str(lhs->qstr);
switch (op) {
case RT_BINARY_OP_SUBSCR:
// string access
// XXX a massive hack!
// 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)) {
// TODO: This implements byte string access for single index so far
return mp_obj_new_int(lhs_str[mp_obj_get_int(rhs_in)]);
} else if (MP_OBJ_IS_TYPE(rhs_in, &slice_type)) {
int start, stop, step;
mp_obj_slice_get(rhs_in, &start, &stop, &step);
assert(step == 1);
int len = strlen(lhs_str);
if (start < 0) {
start = len + start;
}
if (stop <= 0) {
stop = len + stop;
}
return mp_obj_new_str(qstr_from_strn_copy(lhs_str + start, stop - start));
} else {
// Throw TypeError here
assert(0);
}
case RT_BINARY_OP_ADD:
case RT_BINARY_OP_INPLACE_ADD:
if (MP_OBJ_IS_TYPE(rhs_in, &str_type)) {
// add 2 strings
const char *rhs_str = qstr_str(((mp_obj_str_t*)rhs_in)->qstr);
size_t lhs_len = strlen(lhs_str);
size_t rhs_len = strlen(rhs_str);
int alloc_len = lhs_len + rhs_len + 1;
char *val = m_new(char, alloc_len);
memcpy(val, lhs_str, lhs_len);
memcpy(val + lhs_len, rhs_str, rhs_len);
val[lhs_len + rhs_len] = '\0';
return mp_obj_new_str(qstr_from_str_take(val, alloc_len));
}
break;
}
return MP_OBJ_NULL; // op not supported
}
mp_obj_t str_join(mp_obj_t self_in, mp_obj_t arg) {
assert(MP_OBJ_IS_TYPE(self_in, &str_type));
mp_obj_str_t *self = self_in;
// get separation string
const char *sep_str = qstr_str(self->qstr);
size_t sep_len = strlen(sep_str);
// 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_TYPE(seq_items[i], &str_type)) {
goto bad_arg;
}
if (i > 0) {
required_len += sep_len;
}
required_len += strlen(qstr_str(mp_obj_str_get(seq_items[i])));
}
// make joined string
char *joined_str = m_new(char, required_len + 1);
char *s_dest = joined_str;
for (int i = 0; i < seq_len; i++) {
if (i > 0) {
memcpy(s_dest, sep_str, sep_len);
s_dest += sep_len;
}
const char *s2 = qstr_str(mp_obj_str_get(seq_items[i]));
size_t s2_len = strlen(s2);
memcpy(s_dest, s2, s2_len);
s_dest += s2_len;
}
*s_dest = '\0';
// return joined string
return mp_obj_new_str(qstr_from_str_take(joined_str, required_len + 1));
bad_arg:
nlr_jump(mp_obj_new_exception_msg(rt_q_TypeError, "?str.join expecting a list of str's"));
}
void vstr_printf_wrapper(void *env, const char *fmt, ...) {
va_list args;
va_start(args, fmt);
vstr_vprintf(env, fmt, args);
va_end(args);
}
mp_obj_t str_format(int n_args, const mp_obj_t *args) {
assert(MP_OBJ_IS_TYPE(args[0], &str_type));
mp_obj_str_t *self = args[0];
const char *str = qstr_str(self->qstr);
int arg_i = 1;
vstr_t *vstr = vstr_new();
for (; *str; str++) {
if (*str == '{') {
str++;
if (*str == '{') {
vstr_add_char(vstr, '{');
} else if (*str == '}') {
if (arg_i >= n_args) {
nlr_jump(mp_obj_new_exception_msg(rt_q_IndexError, "tuple index out of range"));
}
mp_obj_print_helper(vstr_printf_wrapper, vstr, args[arg_i]);
arg_i++;
}
} else {
vstr_add_char(vstr, *str);
}
}
return mp_obj_new_str(qstr_from_str_take(vstr->buf, vstr->alloc));
}
static MP_DEFINE_CONST_FUN_OBJ_2(str_join_obj, str_join);
static MP_DEFINE_CONST_FUN_OBJ_VAR(str_format_obj, 1, str_format);
const mp_obj_type_t str_type = {
{ &mp_const_type },
"str",
str_print, // print
NULL, // call_n
NULL, // unary_op
str_binary_op, // binary_op
NULL, // getiter
NULL, // iternext
{ // method list
{ "join", &str_join_obj },
{ "format", &str_format_obj },
{ NULL, NULL }, // end-of-list sentinel
},
};
mp_obj_t mp_obj_new_str(qstr qstr) {
mp_obj_str_t *o = m_new_obj(mp_obj_str_t);
o->base.type = &str_type;
o->qstr = qstr;
return o;
}
qstr mp_obj_str_get(mp_obj_t self_in) {
assert(MP_OBJ_IS_TYPE(self_in, &str_type));
mp_obj_str_t *self = self_in;
return self->qstr;
}