/contrib/groff/src/libs/libgroff/unicode.cpp
https://bitbucket.org/freebsd/freebsd-head/ · C++ · 67 lines · 41 code · 3 blank · 23 comment · 25 complexity · 80c56ac3c9af4dfedf8e49f528d31529 MD5 · raw file
- // -*- C++ -*-
- /* Copyright (C) 2002
- Free Software Foundation, Inc.
- Written by Werner Lemberg <wl@gnu.org>
- This file is part of groff.
- groff 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; either version 2, or (at your option) any later
- version.
- groff 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 groff; see the file COPYING. If not, write to the Free Software
- Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA. */
- #include "lib.h"
- #include "cset.h"
- #include "stringclass.h"
- #include "unicode.h"
- const char *check_unicode_name(const char *u)
- {
- if (*u != 'u')
- return 0;
- const char *p = ++u;
- for (;;) {
- int val = 0;
- const char *start = p;
- for (;;) {
- // only uppercase hex digits allowed
- if (!csxdigit(*p))
- return 0;
- if (csdigit(*p))
- val = val*0x10 + (*p-'0');
- else if (csupper(*p))
- val = val*0x10 + (*p-'A'+10);
- else
- return 0;
- // biggest Unicode value is U+10FFFF
- if (val > 0x10FFFF)
- return 0;
- p++;
- if (*p == '\0' || *p == '_')
- break;
- }
- // surrogates not allowed
- if ((val >= 0xD800 && val <= 0xDBFF) || (val >= 0xDC00 && val <= 0xDFFF))
- return 0;
- if (val > 0xFFFF) {
- if (*start == '0') // no leading zeros allowed if > 0xFFFF
- return 0;
- }
- else if (p - start != 4) // otherwise, check for exactly 4 hex digits
- return 0;
- if (*p == '\0')
- break;
- p++;
- }
- return u;
- }