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 91c13e54 2004-02-29 devnull 
 27 91c13e54 2004-02-29 devnull 	T1	= ((1<<(Bit1+1))-1) ^ 0xFF,	/* 0000 0000 */
 28 91c13e54 2004-02-29 devnull 	Tx	= ((1<<(Bitx+1))-1) ^ 0xFF,	/* 1000 0000 */
 29 91c13e54 2004-02-29 devnull 	T2	= ((1<<(Bit2+1))-1) ^ 0xFF,	/* 1100 0000 */
 30 91c13e54 2004-02-29 devnull 	T3	= ((1<<(Bit3+1))-1) ^ 0xFF,	/* 1110 0000 */
 31 91c13e54 2004-02-29 devnull 	T4	= ((1<<(Bit4+1))-1) ^ 0xFF,	/* 1111 0000 */
 32 91c13e54 2004-02-29 devnull 
 33 91c13e54 2004-02-29 devnull 	Rune1	= (1<<(Bit1+0*Bitx))-1,		/* 0000 0000 0111 1111 */
 34 91c13e54 2004-02-29 devnull 	Rune2	= (1<<(Bit2+1*Bitx))-1,		/* 0000 0111 1111 1111 */
 35 91c13e54 2004-02-29 devnull 	Rune3	= (1<<(Bit3+2*Bitx))-1,		/* 1111 1111 1111 1111 */
 36 91c13e54 2004-02-29 devnull 
 37 91c13e54 2004-02-29 devnull 	Maskx	= (1<<Bitx)-1,			/* 0011 1111 */
 38 91c13e54 2004-02-29 devnull 	Testx	= Maskx ^ 0xFF,			/* 1100 0000 */
 39 91c13e54 2004-02-29 devnull 
 40 cbeb0b26 2006-04-01 devnull 	Bad	= Runeerror
 41 91c13e54 2004-02-29 devnull };
 42 91c13e54 2004-02-29 devnull 
 43 91c13e54 2004-02-29 devnull int
 44 91c13e54 2004-02-29 devnull chartorune(Rune *rune, char *str)
 45 91c13e54 2004-02-29 devnull {
 46 91c13e54 2004-02-29 devnull 	int c, c1, c2;
 47 91c13e54 2004-02-29 devnull 	long l;
 48 91c13e54 2004-02-29 devnull 
 49 91c13e54 2004-02-29 devnull 	/*
 50 91c13e54 2004-02-29 devnull 	 * one character sequence
 51 91c13e54 2004-02-29 devnull 	 *	00000-0007F => T1
 52 91c13e54 2004-02-29 devnull 	 */
 53 91c13e54 2004-02-29 devnull 	c = *(uchar*)str;
 54 91c13e54 2004-02-29 devnull 	if(c < Tx) {
 55 91c13e54 2004-02-29 devnull 		*rune = c;
 56 91c13e54 2004-02-29 devnull 		return 1;
 57 91c13e54 2004-02-29 devnull 	}
 58 91c13e54 2004-02-29 devnull 
 59 91c13e54 2004-02-29 devnull 	/*
 60 91c13e54 2004-02-29 devnull 	 * two character sequence
 61 91c13e54 2004-02-29 devnull 	 *	0080-07FF => T2 Tx
 62 91c13e54 2004-02-29 devnull 	 */
 63 91c13e54 2004-02-29 devnull 	c1 = *(uchar*)(str+1) ^ Tx;
 64 91c13e54 2004-02-29 devnull 	if(c1 & Testx)
 65 91c13e54 2004-02-29 devnull 		goto bad;
 66 91c13e54 2004-02-29 devnull 	if(c < T3) {
 67 91c13e54 2004-02-29 devnull 		if(c < T2)
 68 91c13e54 2004-02-29 devnull 			goto bad;
 69 91c13e54 2004-02-29 devnull 		l = ((c << Bitx) | c1) & Rune2;
 70 91c13e54 2004-02-29 devnull 		if(l <= Rune1)
 71 91c13e54 2004-02-29 devnull 			goto bad;
 72 91c13e54 2004-02-29 devnull 		*rune = l;
 73 91c13e54 2004-02-29 devnull 		return 2;
 74 91c13e54 2004-02-29 devnull 	}
 75 91c13e54 2004-02-29 devnull 
 76 91c13e54 2004-02-29 devnull 	/*
 77 91c13e54 2004-02-29 devnull 	 * three character sequence
 78 91c13e54 2004-02-29 devnull 	 *	0800-FFFF => T3 Tx Tx
 79 91c13e54 2004-02-29 devnull 	 */
 80 91c13e54 2004-02-29 devnull 	c2 = *(uchar*)(str+2) ^ Tx;
 81 91c13e54 2004-02-29 devnull 	if(c2 & Testx)
 82 91c13e54 2004-02-29 devnull 		goto bad;
 83 91c13e54 2004-02-29 devnull 	if(c < T4) {
 84 91c13e54 2004-02-29 devnull 		l = ((((c << Bitx) | c1) << Bitx) | c2) & Rune3;
 85 91c13e54 2004-02-29 devnull 		if(l <= Rune2)
 86 91c13e54 2004-02-29 devnull 			goto bad;
 87 91c13e54 2004-02-29 devnull 		*rune = l;
 88 91c13e54 2004-02-29 devnull 		return 3;
 89 91c13e54 2004-02-29 devnull 	}
 90 91c13e54 2004-02-29 devnull 
 91 91c13e54 2004-02-29 devnull 	/*
 92 91c13e54 2004-02-29 devnull 	 * bad decoding
 93 91c13e54 2004-02-29 devnull 	 */
 94 91c13e54 2004-02-29 devnull bad:
 95 91c13e54 2004-02-29 devnull 	*rune = Bad;
 96 91c13e54 2004-02-29 devnull 	return 1;
 97 91c13e54 2004-02-29 devnull }
 98 91c13e54 2004-02-29 devnull 
 99 91c13e54 2004-02-29 devnull int
100 91c13e54 2004-02-29 devnull runetochar(char *str, Rune *rune)
101 91c13e54 2004-02-29 devnull {
102 91c13e54 2004-02-29 devnull 	long c;
103 91c13e54 2004-02-29 devnull 
104 91c13e54 2004-02-29 devnull 	/*
105 91c13e54 2004-02-29 devnull 	 * one character sequence
106 91c13e54 2004-02-29 devnull 	 *	00000-0007F => 00-7F
107 91c13e54 2004-02-29 devnull 	 */
108 91c13e54 2004-02-29 devnull 	c = *rune;
109 91c13e54 2004-02-29 devnull 	if(c <= Rune1) {
110 91c13e54 2004-02-29 devnull 		str[0] = c;
111 91c13e54 2004-02-29 devnull 		return 1;
112 91c13e54 2004-02-29 devnull 	}
113 91c13e54 2004-02-29 devnull 
114 91c13e54 2004-02-29 devnull 	/*
115 91c13e54 2004-02-29 devnull 	 * two character sequence
116 91c13e54 2004-02-29 devnull 	 *	0080-07FF => T2 Tx
117 91c13e54 2004-02-29 devnull 	 */
118 91c13e54 2004-02-29 devnull 	if(c <= Rune2) {
119 91c13e54 2004-02-29 devnull 		str[0] = T2 | (c >> 1*Bitx);
120 91c13e54 2004-02-29 devnull 		str[1] = Tx | (c & Maskx);
121 91c13e54 2004-02-29 devnull 		return 2;
122 91c13e54 2004-02-29 devnull 	}
123 91c13e54 2004-02-29 devnull 
124 91c13e54 2004-02-29 devnull 	/*
125 91c13e54 2004-02-29 devnull 	 * three character sequence
126 91c13e54 2004-02-29 devnull 	 *	0800-FFFF => T3 Tx Tx
127 91c13e54 2004-02-29 devnull 	 */
128 91c13e54 2004-02-29 devnull 	str[0] = T3 |  (c >> 2*Bitx);
129 91c13e54 2004-02-29 devnull 	str[1] = Tx | ((c >> 1*Bitx) & Maskx);
130 91c13e54 2004-02-29 devnull 	str[2] = Tx |  (c & Maskx);
131 91c13e54 2004-02-29 devnull 	return 3;
132 91c13e54 2004-02-29 devnull }
133 91c13e54 2004-02-29 devnull 
134 91c13e54 2004-02-29 devnull int
135 91c13e54 2004-02-29 devnull runelen(long c)
136 91c13e54 2004-02-29 devnull {
137 91c13e54 2004-02-29 devnull 	Rune rune;
138 91c13e54 2004-02-29 devnull 	char str[10];
139 91c13e54 2004-02-29 devnull 
140 91c13e54 2004-02-29 devnull 	rune = c;
141 91c13e54 2004-02-29 devnull 	return runetochar(str, &rune);
142 91c13e54 2004-02-29 devnull }
143 91c13e54 2004-02-29 devnull 
144 91c13e54 2004-02-29 devnull int
145 91c13e54 2004-02-29 devnull runenlen(Rune *r, int nrune)
146 91c13e54 2004-02-29 devnull {
147 91c13e54 2004-02-29 devnull 	int nb, c;
148 91c13e54 2004-02-29 devnull 
149 91c13e54 2004-02-29 devnull 	nb = 0;
150 91c13e54 2004-02-29 devnull 	while(nrune--) {
151 91c13e54 2004-02-29 devnull 		c = *r++;
152 91c13e54 2004-02-29 devnull 		if(c <= Rune1)
153 91c13e54 2004-02-29 devnull 			nb++;
154 91c13e54 2004-02-29 devnull 		else
155 91c13e54 2004-02-29 devnull 		if(c <= Rune2)
156 91c13e54 2004-02-29 devnull 			nb += 2;
157 91c13e54 2004-02-29 devnull 		else
158 91c13e54 2004-02-29 devnull 			nb += 3;
159 91c13e54 2004-02-29 devnull 	}
160 91c13e54 2004-02-29 devnull 	return nb;
161 91c13e54 2004-02-29 devnull }
162 91c13e54 2004-02-29 devnull 
163 91c13e54 2004-02-29 devnull int
164 91c13e54 2004-02-29 devnull fullrune(char *str, int n)
165 91c13e54 2004-02-29 devnull {
166 91c13e54 2004-02-29 devnull 	int c;
167 91c13e54 2004-02-29 devnull 
168 91c13e54 2004-02-29 devnull 	if(n > 0) {
169 91c13e54 2004-02-29 devnull 		c = *(uchar*)str;
170 91c13e54 2004-02-29 devnull 		if(c < Tx)
171 91c13e54 2004-02-29 devnull 			return 1;
172 91c13e54 2004-02-29 devnull 		if(n > 1)
173 91c13e54 2004-02-29 devnull 			if(c < T3 || n > 2)
174 91c13e54 2004-02-29 devnull 				return 1;
175 91c13e54 2004-02-29 devnull 	}
176 91c13e54 2004-02-29 devnull 	return 0;
177 91c13e54 2004-02-29 devnull }