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#include <errno.h>
#include <stdckdint.h>
#include "_attrs.h"
#include "alloc.h"
#include "macros.h"
#include "mbstring.h"
#include "unicode/prop.h"
#include "unicode/string.h"
constexpr rune COMB_DOT_ABOVE = 0x0307;
[[unsequenced, _mlib_inline]] static inline bool
uprop_ccc_0_or_230(rune ch)
{
enum uprop_ccc x = uprop_get_ccc(ch);
return x == 0 || x == 230;
}
char8_t *
u8lower(size_t *dstn, u8view_t sv, caseflags_t flags, allocator_t mem)
{
ASSUME(dstn != nullptr);
struct lcctx ctx = {
.az_or_tr = flags & CF_LANG_AZ,
.lt = flags & CF_LANG_LT,
};
rune ch;
size_t n, before_dot_cnt, more_above_cnt;
struct {
bool before;
size_t after;
} final_sigma = {
.before = true,
};
n = before_dot_cnt = more_above_cnt = 0;
size_t bufsz;
/* TODO: Also use U8LOWER_SCALE */
if (ckd_mul(&bufsz, sv.len, (size_t)U8LOWER_SCALE_LT)) {
errno = EOVERFLOW;
return nullptr;
}
char8_t *dst = new(mem, typeof(*dst), bufsz);
while (u8next(&ch, &sv)) {
rune next = 0;
if (sv.len > 0)
u8tor(&next, sv.p);
if (ctx.az_or_tr || ctx.lt) {
if (before_dot_cnt == 0 || more_above_cnt == 0) {
rune ch = 0;
before_dot_cnt = more_above_cnt = 0;
u8view_t cpy = sv;
do {
before_dot_cnt++;
more_above_cnt++;
} while (u8next(&ch, &cpy) && !uprop_ccc_0_or_230(ch));
if (ch != COMB_DOT_ABOVE)
before_dot_cnt = 0;
if (uprop_get_ccc(ch) != 230)
more_above_cnt = 0;
} else {
before_dot_cnt--;
more_above_cnt--;
}
}
if (final_sigma.after == 0) {
rune ch = 0;
u8view_t cpy = sv;
do
final_sigma.after++;
while (u8next(&ch, &cpy) && uprop_is_ci(ch));
if (!uprop_is_cased(ch))
final_sigma.after = 0;
} else
final_sigma.after--;
ctx.before_dot = before_dot_cnt > 0;
ctx.more_above = more_above_cnt > 0;
ctx.final_sigma = final_sigma.before && final_sigma.after == 0;
struct rview rv = uprop_get_lc(ch, ctx);
for (size_t i = 0; i < rv.len; i++)
n += rtou8(dst + n, bufsz - n, rv.p[i]);
ctx.after_I = (ch == 'I') || (ctx.after_I && !uprop_ccc_0_or_230(ch));
if (uprop_is_cased(ch))
final_sigma.before = true;
else if (!uprop_is_ci(ch))
final_sigma.before = false;
}
*dstn = n;
return resz(mem, dst, bufsz, n);
}
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