cosmopolitan/libc/str/tprecode8to16.c

49 lines
2.5 KiB
C
Raw Normal View History

2020-06-15 14:18:57 +00:00
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi
Copyright 2020 Justine Alexandra Roberts Tunney
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
#include "libc/conv/conv.h"
#include "libc/str/str.h"
#include "libc/str/tpdecode.h"
2020-06-15 14:18:57 +00:00
/**
* Transcodes UTF-8 to UTF-16.
*
* @param dst is output buffer
* @param dstsize is shorts in dst
* @param src is NUL-terminated UTF-8 input string
* @return number of shorts written excluding NUL
*/
size_t tprecode8to16(char16_t *dst, size_t dstsize, const char *src) {
size_t i = 0;
if (dstsize) {
for (;;) {
wint_t wc;
src += abs(tpdecode(src, &wc));
if (!wc || dstsize == 1) {
dst[i] = u'\0';
break;
}
size_t got = abs(pututf16(&dst[i], dstsize, wc, false));
dstsize -= got;
i += got;
}
}
return i;
}