diff options
| -rw-r--r-- | include/unicode/string.h | 2 | ||||
| -rw-r--r-- | lib/unicode/string/u8lower.c | 46 |
2 files changed, 48 insertions, 0 deletions
diff --git a/include/unicode/string.h b/include/unicode/string.h index 6197235..0c1786c 100644 --- a/include/unicode/string.h +++ b/include/unicode/string.h @@ -16,6 +16,8 @@ enum [[clang::__flag_enum__]] caseflags { size_t u8glen(const char8_t *, size_t); size_t u8gnext(struct u8view *, const char8_t **, size_t *); +size_t u8lower(char8_t *restrict, size_t, const char8_t *, size_t, + enum caseflags); size_t u8upper(char8_t *restrict, size_t, const char8_t *, size_t, enum caseflags); diff --git a/lib/unicode/string/u8lower.c b/lib/unicode/string/u8lower.c new file mode 100644 index 0000000..052217f --- /dev/null +++ b/lib/unicode/string/u8lower.c @@ -0,0 +1,46 @@ +#include "mbstring.h" +#include "unicode/prop.h" +#include "unicode/string.h" + +constexpr rune COMB_GRAVE = 0x0300; +constexpr rune COMB_ACUTE = 0x0301; +constexpr rune COMB_TILDE = 0x0303; +constexpr rune COMB_DOT_ABOVE = 0x0307; + +size_t +u8lower(char8_t *restrict dst, size_t dstn, const char8_t *src, size_t srcn, + enum caseflags flags) +{ + struct lcctx ctx = { + .az_or_tr = flags & CF_LANG_AZ, + .lt = flags & CF_LANG_LT, + }; + + rune ch; + size_t n = 0; + + while (u8next(&ch, &src, &srcn)) { + /* TODO: Set ‘eow’ once word-segmentation is implemented */ + + rune next = 0; + if (srcn > 0) + u8tor(&next, src); + ctx.before_dot = next == COMB_DOT_ABOVE; + ctx.before_acc = next == COMB_GRAVE + || next == COMB_ACUTE + || next == COMB_TILDE; + + struct rview rv = uprop_get_lc(ch, ctx); + for (size_t i = 0; i < rv.len; i++) { + if (n >= dstn) { + char8_t buf[U8_LEN_MAX]; + n += rtou8(buf, sizeof(buf), rv.p[i]); + } else + n += rtou8(dst + n, dstn - n, rv.p[i]); + } + + ctx.after_I = ch == 'I'; + } + + return n; +} |