1 91c13e54 2004-02-29 devnull /*
  2 91c13e54 2004-02-29 devnull  * The authors of this software are Rob Pike and Ken Thompson.
  3 91c13e54 2004-02-29 devnull  *              Copyright (c) 2002 by Lucent Technologies.
  4 91c13e54 2004-02-29 devnull  * Permission to use, copy, modify, and distribute this software for any
  5 91c13e54 2004-02-29 devnull  * purpose without fee is hereby granted, provided that this entire notice
  6 91c13e54 2004-02-29 devnull  * is included in all copies of any software which is or includes a copy
  7 91c13e54 2004-02-29 devnull  * or modification of this software and in all copies of the supporting
  8 91c13e54 2004-02-29 devnull  * documentation for such software.
  9 91c13e54 2004-02-29 devnull  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
 10 37488654 2004-12-29 devnull  * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE
 11 37488654 2004-12-29 devnull  * ANY REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
 12 91c13e54 2004-02-29 devnull  * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
 13 91c13e54 2004-02-29 devnull  */
 14 91c13e54 2004-02-29 devnull #include <stdarg.h>
 15 91c13e54 2004-02-29 devnull #include <string.h>
 16 e5aa96ac 2004-12-26 devnull #include "plan9.h"
 17 91c13e54 2004-02-29 devnull #include "utf.h"
 18 91c13e54 2004-02-29 devnull 
 19 91c13e54 2004-02-29 devnull enum
 20 91c13e54 2004-02-29 devnull {
 21 91c13e54 2004-02-29 devnull 	Bit1	= 7,
 22 91c13e54 2004-02-29 devnull 	Bitx	= 6,
 23 91c13e54 2004-02-29 devnull 	Bit2	= 5,
 24 91c13e54 2004-02-29 devnull 	Bit3	= 4,
 25 91c13e54 2004-02-29 devnull 	Bit4	= 3,
 26 0cadb430 2009-09-11 russcox 	Bit5	= 2,
 27 91c13e54 2004-02-29 devnull 
 28 91c13e54 2004-02-29 devnull 	T1	= ((1<<(Bit1+1))-1) ^ 0xFF,	/* 0000 0000 */
 29 91c13e54 2004-02-29 devnull 	Tx	= ((1<<(Bitx+1))-1) ^ 0xFF,	/* 1000 0000 */
 30 91c13e54 2004-02-29 devnull 	T2	= ((1<<(Bit2+1))-1) ^ 0xFF,	/* 1100 0000 */
 31 91c13e54 2004-02-29 devnull 	T3	= ((1<<(Bit3+1))-1) ^ 0xFF,	/* 1110 0000 */
 32 91c13e54 2004-02-29 devnull 	T4	= ((1<<(Bit4+1))-1) ^ 0xFF,	/* 1111 0000 */
 33 0cadb430 2009-09-11 russcox 	T5	= ((1<<(Bit5+1))-1) ^ 0xFF,	/* 1111 1000 */
 34 91c13e54 2004-02-29 devnull 
 35 0cadb430 2009-09-11 russcox 	Rune1	= (1<<(Bit1+0*Bitx))-1,		/* 0000 0000 0000 0000 0111 1111 */
 36 0cadb430 2009-09-11 russcox 	Rune2	= (1<<(Bit2+1*Bitx))-1,		/* 0000 0000 0000 0111 1111 1111 */
 37 0cadb430 2009-09-11 russcox 	Rune3	= (1<<(Bit3+2*Bitx))-1,		/* 0000 0000 1111 1111 1111 1111 */
 38 0cadb430 2009-09-11 russcox 	Rune4	= (1<<(Bit4+3*Bitx))-1,		/* 0011 1111 1111 1111 1111 1111 */
 39 91c13e54 2004-02-29 devnull 
 40 91c13e54 2004-02-29 devnull 	Maskx	= (1<<Bitx)-1,			/* 0011 1111 */
 41 91c13e54 2004-02-29 devnull 	Testx	= Maskx ^ 0xFF,			/* 1100 0000 */
 42 91c13e54 2004-02-29 devnull 
 43 cbeb0b26 2006-04-01 devnull 	Bad	= Runeerror
 44 91c13e54 2004-02-29 devnull };
 45 91c13e54 2004-02-29 devnull 
 46 91c13e54 2004-02-29 devnull int
 47 91c13e54 2004-02-29 devnull chartorune(Rune *rune, char *str)
 48 91c13e54 2004-02-29 devnull {
 49 0cadb430 2009-09-11 russcox 	int c, c1, c2, c3;
 50 91c13e54 2004-02-29 devnull 	long l;
 51 91c13e54 2004-02-29 devnull 
 52 91c13e54 2004-02-29 devnull 	/*
 53 91c13e54 2004-02-29 devnull 	 * one character sequence
 54 91c13e54 2004-02-29 devnull 	 *	00000-0007F => T1
 55 91c13e54 2004-02-29 devnull 	 */
 56 91c13e54 2004-02-29 devnull 	c = *(uchar*)str;
 57 91c13e54 2004-02-29 devnull 	if(c < Tx) {
 58 91c13e54 2004-02-29 devnull 		*rune = c;
 59 91c13e54 2004-02-29 devnull 		return 1;
 60 91c13e54 2004-02-29 devnull 	}
 61 91c13e54 2004-02-29 devnull 
 62 91c13e54 2004-02-29 devnull 	/*
 63 91c13e54 2004-02-29 devnull 	 * two character sequence
 64 91c13e54 2004-02-29 devnull 	 *	0080-07FF => T2 Tx
 65 91c13e54 2004-02-29 devnull 	 */
 66 91c13e54 2004-02-29 devnull 	c1 = *(uchar*)(str+1) ^ Tx;
 67 91c13e54 2004-02-29 devnull 	if(c1 & Testx)
 68 91c13e54 2004-02-29 devnull 		goto bad;
 69 91c13e54 2004-02-29 devnull 	if(c < T3) {
 70 91c13e54 2004-02-29 devnull 		if(c < T2)
 71 91c13e54 2004-02-29 devnull 			goto bad;
 72 91c13e54 2004-02-29 devnull 		l = ((c << Bitx) | c1) & Rune2;
 73 91c13e54 2004-02-29 devnull 		if(l <= Rune1)
 74 91c13e54 2004-02-29 devnull 			goto bad;
 75 91c13e54 2004-02-29 devnull 		*rune = l;
 76 91c13e54 2004-02-29 devnull 		return 2;
 77 91c13e54 2004-02-29 devnull 	}
 78 91c13e54 2004-02-29 devnull 
 79 91c13e54 2004-02-29 devnull 	/*
 80 91c13e54 2004-02-29 devnull 	 * three character sequence
 81 91c13e54 2004-02-29 devnull 	 *	0800-FFFF => T3 Tx Tx
 82 91c13e54 2004-02-29 devnull 	 */
 83 91c13e54 2004-02-29 devnull 	c2 = *(uchar*)(str+2) ^ Tx;
 84 91c13e54 2004-02-29 devnull 	if(c2 & Testx)
 85 91c13e54 2004-02-29 devnull 		goto bad;
 86 91c13e54 2004-02-29 devnull 	if(c < T4) {
 87 91c13e54 2004-02-29 devnull 		l = ((((c << Bitx) | c1) << Bitx) | c2) & Rune3;
 88 91c13e54 2004-02-29 devnull 		if(l <= Rune2)
 89 91c13e54 2004-02-29 devnull 			goto bad;
 90 91c13e54 2004-02-29 devnull 		*rune = l;
 91 91c13e54 2004-02-29 devnull 		return 3;
 92 91c13e54 2004-02-29 devnull 	}
 93 91c13e54 2004-02-29 devnull 
 94 91c13e54 2004-02-29 devnull 	/*
 95 0cadb430 2009-09-11 russcox 	 * four character sequence
 96 0cadb430 2009-09-11 russcox 	 *	10000-10FFFF => T4 Tx Tx Tx
 97 0cadb430 2009-09-11 russcox 	 */
 98 0cadb430 2009-09-11 russcox 	if(UTFmax >= 4) {
 99 0cadb430 2009-09-11 russcox 		c3 = *(uchar*)(str+3) ^ Tx;
100 0cadb430 2009-09-11 russcox 		if(c3 & Testx)
101 0cadb430 2009-09-11 russcox 			goto bad;
102 0cadb430 2009-09-11 russcox 		if(c < T5) {
103 0cadb430 2009-09-11 russcox 			l = ((((((c << Bitx) | c1) << Bitx) | c2) << Bitx) | c3) & Rune4;
104 0cadb430 2009-09-11 russcox 			if(l <= Rune3)
105 0cadb430 2009-09-11 russcox 				goto bad;
106 0cadb430 2009-09-11 russcox 			if(l > Runemax)
107 0cadb430 2009-09-11 russcox 				goto bad;
108 0cadb430 2009-09-11 russcox 			*rune = l;
109 0cadb430 2009-09-11 russcox 			return 4;
110 0cadb430 2009-09-11 russcox 		}
111 0cadb430 2009-09-11 russcox 	}
112 0cadb430 2009-09-11 russcox 
113 0cadb430 2009-09-11 russcox 	/*
114 91c13e54 2004-02-29 devnull 	 * bad decoding
115 91c13e54 2004-02-29 devnull 	 */
116 91c13e54 2004-02-29 devnull bad:
117 91c13e54 2004-02-29 devnull 	*rune = Bad;
118 91c13e54 2004-02-29 devnull 	return 1;
119 91c13e54 2004-02-29 devnull }
120 91c13e54 2004-02-29 devnull 
121 91c13e54 2004-02-29 devnull int
122 91c13e54 2004-02-29 devnull runetochar(char *str, Rune *rune)
123 91c13e54 2004-02-29 devnull {
124 91c13e54 2004-02-29 devnull 	long c;
125 91c13e54 2004-02-29 devnull 
126 91c13e54 2004-02-29 devnull 	/*
127 91c13e54 2004-02-29 devnull 	 * one character sequence
128 91c13e54 2004-02-29 devnull 	 *	00000-0007F => 00-7F
129 91c13e54 2004-02-29 devnull 	 */
130 91c13e54 2004-02-29 devnull 	c = *rune;
131 91c13e54 2004-02-29 devnull 	if(c <= Rune1) {
132 91c13e54 2004-02-29 devnull 		str[0] = c;
133 91c13e54 2004-02-29 devnull 		return 1;
134 91c13e54 2004-02-29 devnull 	}
135 91c13e54 2004-02-29 devnull 
136 91c13e54 2004-02-29 devnull 	/*
137 91c13e54 2004-02-29 devnull 	 * two character sequence
138 0cadb430 2009-09-11 russcox 	 *	00080-007FF => T2 Tx
139 91c13e54 2004-02-29 devnull 	 */
140 91c13e54 2004-02-29 devnull 	if(c <= Rune2) {
141 91c13e54 2004-02-29 devnull 		str[0] = T2 | (c >> 1*Bitx);
142 91c13e54 2004-02-29 devnull 		str[1] = Tx | (c & Maskx);
143 91c13e54 2004-02-29 devnull 		return 2;
144 91c13e54 2004-02-29 devnull 	}
145 91c13e54 2004-02-29 devnull 
146 91c13e54 2004-02-29 devnull 	/*
147 91c13e54 2004-02-29 devnull 	 * three character sequence
148 0cadb430 2009-09-11 russcox 	 *	00800-0FFFF => T3 Tx Tx
149 91c13e54 2004-02-29 devnull 	 */
150 0cadb430 2009-09-11 russcox 	if(c > Runemax)
151 0cadb430 2009-09-11 russcox 		c = Runeerror;
152 0cadb430 2009-09-11 russcox 	if(c <= Rune3) {
153 0cadb430 2009-09-11 russcox 		str[0] = T3 |  (c >> 2*Bitx);
154 0cadb430 2009-09-11 russcox 		str[1] = Tx | ((c >> 1*Bitx) & Maskx);
155 0cadb430 2009-09-11 russcox 		str[2] = Tx |  (c & Maskx);
156 0cadb430 2009-09-11 russcox 		return 3;
157 0cadb430 2009-09-11 russcox 	}
158 0cadb430 2009-09-11 russcox 	
159 0cadb430 2009-09-11 russcox 	/*
160 0cadb430 2009-09-11 russcox 	 * four character sequence
161 0cadb430 2009-09-11 russcox 	 *	010000-1FFFFF => T4 Tx Tx Tx
162 0cadb430 2009-09-11 russcox 	 */
163 0cadb430 2009-09-11 russcox 	str[0] = T4 |  (c >> 3*Bitx);
164 0cadb430 2009-09-11 russcox 	str[1] = Tx | ((c >> 2*Bitx) & Maskx);
165 0cadb430 2009-09-11 russcox 	str[2] = Tx | ((c >> 1*Bitx) & Maskx);
166 0cadb430 2009-09-11 russcox 	str[3] = Tx |  (c & Maskx);
167 0cadb430 2009-09-11 russcox 	return 4;
168 91c13e54 2004-02-29 devnull }
169 91c13e54 2004-02-29 devnull 
170 91c13e54 2004-02-29 devnull int
171 91c13e54 2004-02-29 devnull runelen(long c)
172 91c13e54 2004-02-29 devnull {
173 91c13e54 2004-02-29 devnull 	Rune rune;
174 91c13e54 2004-02-29 devnull 	char str[10];
175 91c13e54 2004-02-29 devnull 
176 91c13e54 2004-02-29 devnull 	rune = c;
177 91c13e54 2004-02-29 devnull 	return runetochar(str, &rune);
178 91c13e54 2004-02-29 devnull }
179 91c13e54 2004-02-29 devnull 
180 91c13e54 2004-02-29 devnull int
181 91c13e54 2004-02-29 devnull runenlen(Rune *r, int nrune)
182 91c13e54 2004-02-29 devnull {
183 91c13e54 2004-02-29 devnull 	int nb, c;
184 91c13e54 2004-02-29 devnull 
185 91c13e54 2004-02-29 devnull 	nb = 0;
186 91c13e54 2004-02-29 devnull 	while(nrune--) {
187 91c13e54 2004-02-29 devnull 		c = *r++;
188 91c13e54 2004-02-29 devnull 		if(c <= Rune1)
189 91c13e54 2004-02-29 devnull 			nb++;
190 91c13e54 2004-02-29 devnull 		else
191 91c13e54 2004-02-29 devnull 		if(c <= Rune2)
192 91c13e54 2004-02-29 devnull 			nb += 2;
193 91c13e54 2004-02-29 devnull 		else
194 0cadb430 2009-09-11 russcox 		if(c <= Rune3 || c > Runemax)
195 91c13e54 2004-02-29 devnull 			nb += 3;
196 0cadb430 2009-09-11 russcox 		else
197 0cadb430 2009-09-11 russcox 			nb += 4;
198 91c13e54 2004-02-29 devnull 	}
199 91c13e54 2004-02-29 devnull 	return nb;
200 91c13e54 2004-02-29 devnull }
201 91c13e54 2004-02-29 devnull 
202 91c13e54 2004-02-29 devnull int
203 91c13e54 2004-02-29 devnull fullrune(char *str, int n)
204 91c13e54 2004-02-29 devnull {
205 91c13e54 2004-02-29 devnull 	int c;
206 91c13e54 2004-02-29 devnull 
207 0cadb430 2009-09-11 russcox 	if(n <= 0)
208 0cadb430 2009-09-11 russcox 		return 0;
209 0cadb430 2009-09-11 russcox 	c = *(uchar*)str;
210 0cadb430 2009-09-11 russcox 	if(c < Tx)
211 0cadb430 2009-09-11 russcox 		return 1;
212 0cadb430 2009-09-11 russcox 	if(c < T3)
213 0cadb430 2009-09-11 russcox 		return n >= 2;
214 0cadb430 2009-09-11 russcox 	if(UTFmax == 3 || c < T4)
215 0cadb430 2009-09-11 russcox 		return n >= 3;
216 0cadb430 2009-09-11 russcox 	return n >= 4;
217 91c13e54 2004-02-29 devnull }