118 lines
3.4 KiB
C
118 lines
3.4 KiB
C
/* $Id$
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Part of SWI-Prolog
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Author: Jan Wielemaker and Anjo Anjewierden
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E-mail: jan@swi.psy.uva.nl
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WWW: http://www.swi-prolog.org
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Copyright (C): 1985-2002, University of Amsterdam
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <string.h> /* get size_t */
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#include "pl-utf8.h"
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/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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UTF-8 Decoding, based on http://www.cl.cam.ac.uk/~mgk25/unicode.html
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- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
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#define CONT(i) ISUTF8_CB(in[i])
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#define VAL(i, s) ((in[i]&0x3f) << s)
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char *
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_PL__utf8_get_char(const char *in, int *chr)
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{ /* 2-byte, 0x80-0x7ff */
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if ( (in[0]&0xe0) == 0xc0 && CONT(1) )
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{ *chr = ((in[0]&0x1f) << 6)|VAL(1,0);
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return (char *)in+2;
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}
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/* 3-byte, 0x800-0xffff */
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if ( (in[0]&0xf0) == 0xe0 && CONT(1) && CONT(2) )
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{ *chr = ((in[0]&0xf) << 12)|VAL(1,6)|VAL(2,0);
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return (char *)in+3;
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}
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/* 4-byte, 0x10000-0x1FFFFF */
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if ( (in[0]&0xf8) == 0xf0 && CONT(1) && CONT(2) && CONT(3) )
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{ *chr = ((in[0]&0x7) << 18)|VAL(1,12)|VAL(2,6)|VAL(3,0);
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return (char *)in+4;
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}
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/* 5-byte, 0x200000-0x3FFFFFF */
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if ( (in[0]&0xfc) == 0xf8 && CONT(1) && CONT(2) && CONT(3) && CONT(4) )
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{ *chr = ((in[0]&0x3) << 24)|VAL(1,18)|VAL(2,12)|VAL(3,6)|VAL(4,0);
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return (char *)in+5;
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}
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/* 6-byte, 0x400000-0x7FFFFFF */
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if ( (in[0]&0xfe) == 0xfc && CONT(1) && CONT(2) && CONT(3) && CONT(4) && CONT(5) )
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{ *chr = ((in[0]&0x1) << 30)|VAL(1,24)|VAL(2,18)|VAL(3,12)|VAL(4,6)|VAL(5,0);
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return (char *)in+4;
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}
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*chr = *in;
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return (char *)in+1;
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}
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char *
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_PL__utf8_put_char(char *out, int chr)
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{ if ( chr < 0x80 )
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{ *out++ = chr;
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} else if ( chr < 0x800 )
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{ *out++ = 0xc0|((chr>>6)&0x1f);
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*out++ = 0x80|(chr&0x3f);
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} else if ( chr < 0x10000 )
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{ *out++ = 0xe0|((chr>>12)&0x0f);
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*out++ = 0x80|((chr>>6)&0x3f);
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*out++ = 0x80|(chr&0x3f);
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} else if ( chr < 0x200000 )
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{ *out++ = 0xf0|((chr>>18)&0x07);
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*out++ = 0x80|((chr>>12)&0x3f);
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*out++ = 0x80|((chr>>6)&0x3f);
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*out++ = 0x80|(chr&0x3f);
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} else if ( chr < 0x4000000 )
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{ *out++ = 0xf8|((chr>>24)&0x03);
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*out++ = 0x80|((chr>>18)&0x3f);
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*out++ = 0x80|((chr>>12)&0x3f);
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*out++ = 0x80|((chr>>6)&0x3f);
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*out++ = 0x80|(chr&0x3f);
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} else if ( (unsigned)chr < 0x80000000 )
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{ *out++ = 0xfc|((chr>>30)&0x01);
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*out++ = 0x80|((chr>>24)&0x3f);
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*out++ = 0x80|((chr>>18)&0x3f);
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*out++ = 0x80|((chr>>12)&0x3f);
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*out++ = 0x80|((chr>>6)&0x3f);
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*out++ = 0x80|(chr&0x3f);
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}
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return out;
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}
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size_t
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utf8_strlen(const char *s, size_t len)
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{ const char *e = &s[len];
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unsigned int l = 0;
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while(s<e)
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{ int chr;
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s = utf8_get_char(s, &chr);
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l++;
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}
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return l;
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}
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