From 5f2b09982312c98863eb9a8dfe2c608b81f58259 Mon Sep 17 00:00:00 2001 From: "Manuel A. Fernandez Montecelo" Date: Thu, 26 May 2016 16:48:15 +0100 Subject: Imported Upstream version 0.9.6 --- lib/unigbrk/ulc-grapheme-breaks.c | 130 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 130 insertions(+) create mode 100644 lib/unigbrk/ulc-grapheme-breaks.c (limited to 'lib/unigbrk/ulc-grapheme-breaks.c') diff --git a/lib/unigbrk/ulc-grapheme-breaks.c b/lib/unigbrk/ulc-grapheme-breaks.c new file mode 100644 index 0000000..d8bf924 --- /dev/null +++ b/lib/unigbrk/ulc-grapheme-breaks.c @@ -0,0 +1,130 @@ +/* Grapheme cluster breaks function. + Copyright (C) 2001-2003, 2006-2015 Free Software Foundation, Inc. + Written by Ben Pfaff , 2010, + based on code written by Bruno Haible , 2009. + + This program is free software: you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published + by the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see . */ + +#include + +/* Specification. */ +#include "unigbrk.h" + +#include +#include + +#include "c-ctype.h" +#include "c-strcaseeq.h" +#include "localcharset.h" +#include "uniconv.h" + +static int +is_utf8_encoding (const char *encoding) +{ + if (STRCASEEQ (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0, 0)) + return 1; + return 0; +} + +#if C_CTYPE_ASCII +/* Assume that every ASCII character starts a new grapheme, which is often + true, except that CR-LF is a single grapheme. */ +static void +ascii_grapheme_breaks (const char *s, size_t n, char *p) +{ + size_t i; + + p[0] = 1; + for (i = 1; i < n; i++) + { + bool is_ascii = c_isprint (s[i]) || c_isspace (s[i]); + p[i] = is_ascii && (s[i] != '\n' || s[i - 1] != '\r'); + } +} +#endif + +/* Grapheme boundaries in a string in an arbitrary encoding. + + We convert the input string to Unicode. + + The standardized Unicode encodings are UTF-8, UCS-2, UCS-4, UTF-16, + UTF-16BE, UTF-16LE, UTF-7. UCS-2 supports only characters up to + \U0000FFFF. UTF-16 and variants support only characters up to + \U0010FFFF. UTF-7 is way too complex and not supported by glibc-2.1. + UCS-4 specification leaves doubts about endianness and byte order mark. + glibc currently interprets it as big endian without byte order mark, + but this is not backed by an RFC. So we use UTF-8. It supports + characters up to \U7FFFFFFF and is unambiguously defined. */ + +void +ulc_grapheme_breaks (const char *s, size_t n, char *p) +{ + if (n > 0) + { + const char *encoding = locale_charset (); + + if (is_utf8_encoding (encoding)) + u8_grapheme_breaks ((const uint8_t *) s, n, p); + else + { + /* Convert the string to UTF-8 and build a translation table + from offsets into s to offsets into the translated string. */ + size_t *offsets = (size_t *) malloc (n * sizeof (size_t)); + + if (offsets != NULL) + { + uint8_t *t; + size_t m; + + t = u8_conv_from_encoding (encoding, iconveh_question_mark, + s, n, offsets, NULL, &m); + if (t != NULL) + { + char *q = (char *) (m > 0 ? malloc (m) : NULL); + + if (m == 0 || q != NULL) + { + size_t i; + + /* Determine the grapheme breaks of the UTF-8 string. */ + u8_grapheme_breaks (t, m, q); + + /* Translate the result back to the original string. */ + memset (p, 0, n); + for (i = 0; i < n; i++) + if (offsets[i] != (size_t)(-1)) + p[i] = q[offsets[i]]; + + free (q); + free (t); + free (offsets); + return; + } + free (t); + } + free (offsets); + } + + /* Impossible to convert. */ +#if C_CTYPE_ASCII + /* Fall back to ASCII as best we can. */ + ascii_grapheme_breaks (s, n, p); +#else + /* We cannot make any assumptions. */ + p[0] = 1; + memset (p + 1, 0, n - 1); +#endif + } + } +} -- cgit v1.2.3