cosmopolitan/libc/str/wcwidth.c

/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8   -*-│
│ vi: set noet ft=c ts=8 sw=8 fenc=utf-8                                   :vi │
╚──────────────────────────────────────────────────────────────────────────────╝
│                                                                              │
│  Musl Libc                                                                   │
│  Copyright © 2005-2014 Rich Felker, et al.                                   │
│                                                                              │
│  Permission is hereby granted, free of charge, to any person obtaining       │
│  a copy of this software and associated documentation files (the             │
│  "Software"), to deal in the Software without restriction, including         │
│  without limitation the rights to use, copy, modify, merge, publish,         │
│  distribute, sublicense, and/or sell copies of the Software, and to          │
│  permit persons to whom the Software is furnished to do so, subject to       │
│  the following conditions:                                                   │
│                                                                              │
│  The above copyright notice and this permission notice shall be              │
│  included in all copies or substantial portions of the Software.             │
│                                                                              │
│  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,             │
│  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF          │
│  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.      │
│  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY        │
│  CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,        │
│  TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE           │
│  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                      │
│                                                                              │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/str/unicode.h"
__static_yoink("musl_libc_notice");
// clang-format off

static const unsigned char table[] = {
#include "nonspacing.inc"
};

static const unsigned char wtable[] = {
#include "wide.inc"
};

int wcwidth(wchar_t wc)
{
	if ((int)wc < 0xff) {
		if ((int)wc >= 0)
			return ((wc+1) & 0x7f) >= 0x21 ? 1 : wc ? -1 : 0;
		return -1;
	}
	if ((wc & 0xfffeffffU) < 0xfffe) {
		if ((table[table[wc>>8]*32+((wc&255)>>3)]>>(wc&7))&1)
			return 0;
		if ((wtable[wtable[wc>>8]*32+((wc&255)>>3)]>>(wc&7))&1)
			return 2;
		return 1;
	}
	if ((wc & 0xfffe) == 0xfffe)
		return -1;
	if (wc-0x20000U < 0x20000)
		return 2;
	if (wc == 0xe0001 || wc-0xe0020U < 0x5f || wc-0xe0100U < 0xef)
		return 0;
	return 1;
}