cosmopolitan/libc/str/wcwidth.c
2023-05-10 04:20:47 -07:00

59 lines
3.1 KiB
C

/*-*- 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 │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/intrin/likely.h"
#include "libc/str/str.h"
#include "libc/str/unicode.h"
extern const uint8_t kEastAsianWidth[];
extern const uint32_t kEastAsianWidthBits;
extern const uint8_t kCombiningChars[];
extern const uint32_t kCombiningCharsBits;
/**
* Returns cell width of monospace character.
*/
int wcwidth(wchar_t c) {
#ifdef __x86_64__
if (LIKELY(32 <= c && c < 127)) {
return 1;
} else if (!c) {
return 0;
} else if ((0 < c && c < 32) || (0x7f <= c && c < 0xA0)) {
return -1;
} else if ((0 <= c && c < kCombiningCharsBits) &&
!!(kCombiningChars[c >> 3] & (1 << (c & 7)))) {
return 0;
} else if (0 <= c && c < kEastAsianWidthBits) {
return 1 + !!(kEastAsianWidth[c >> 3] & (1 << (c & 7)));
} else {
return 1;
}
#else
if (!c) return 0;
if (c < 0 || iswcntrl(c)) return -1;
return 1 +
(c >= 0x1100 &&
(c <= 0x115f || c == 0x2329 || c == 0x232a ||
(c >= 0x2e80 && c <= 0xa4cf && c != 0x303f) ||
(c >= 0xac00 && c <= 0xd7a3) || (c >= 0xf900 && c <= 0xfaff) ||
(c >= 0xfe10 && c <= 0xfe19) || (c >= 0xfe30 && c <= 0xfe6f) ||
(c >= 0xff00 && c <= 0xff60) || (c >= 0xffe0 && c <= 0xffe6) ||
(c >= 0x20000 && c <= 0x2fffd) || (c >= 0x30000 && c <= 0x3fffd)));
#endif
}