intl/lwbrk/rulebrk.c

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4 #define TH_UNICODE
   5
   6 #include <stdlib.h>
   7 #include <stdint.h>
   8 #include <assert.h>
   9 #include "th_char.h"
  10 #define th_isalpha(c) (((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z'))
  11 #define th_isspace(c) ((c) == ' ' || (c) == '\t')
  12
  13 /*
  14 /////////////////////////////////////////////////
  15 // Thai character type array
  16 */
  17
  18 typedef unsigned short twb_t;
  19 extern const twb_t _TwbType[0x100 - 0xa0];
  20
  21 /*
  22 // bit definition
  23 */
  24
  25 #define VRS 0x0001
  26 #define VRE 0x0002
  27 #define VRX 0x0004
  28
  29 #define VRA 0x0008
  30
  31 #define VLA 0x0010
  32 #define VLO 0x0020
  33 #define VLI 0x0040
  34
  35 #define VC 0x0080
  36
  37 #define CC 0x0100
  38 #define CS 0x0200
  39
  40 #define C2 0x0400
  41 #define CHB 0x0800
  42 #define CHE 0x1000
  43
  44 #define MT 0x2000
  45 /*
  46 //_#define me 0x2000
  47 */
  48 #define M 0x4000
  49
  50 #define T 0x8000
  51
  52 #define VL (VLA | VLO | VLI)
  53 #define VR (VRS | VRE | VRX)
  54 #define NE (VL | VRS)
  55 #define NB (VR | M)
  56 #define V (VL | VR)
  57 #define CX (CC | CS)
  58 #define C (CX | VC)
  59 #define A (C | V | M)
  60
  61 #define twbtype(c) (_TwbType[th_zcode(c)])
  62
  63 #ifndef TRUE
  64 #  define TRUE 1
  65 #  define FALSE 0
  66 #endif
  67 #define RETURN(b) return (b)
  68
  69 /*
  70 /////////////////////////////////////////////////
  71 */
  72
  73 int TrbWordBreakPos(const th_char* pstr, int left, const th_char* rstr,
  74                     int right)
  75 /*                 const ThBreakIterator *it, const th_char **p)*/
  76 {
  77   /*
  78   //int left, right;
  79   //const th_char *s = *p;
  80   */
  81   const th_char* lstr = pstr + left;
  82   th_char _c[6];
  83   twb_t _t[6];
  84 #define c(i) (_c[(i) + 3])
  85 #define t(i) (_t[(i) + 3])
  86   int i, j;
  87
  88   /*
  89   //left = s - it->begin;
  90   */
  91   if (left < 0) return -1;
  92   /*
  93   //right = (it->end == NULL) ? 4 : it->begin - s;
  94   */
  95   if (right < 1) return -1;
  96
  97   /*
  98   // get c(0), t(0)
  99   */
 100   c(0) = rstr[0]; /* may be '\0' */
 101   if (!th_isthai(c(0))) return -1;
 102   t(0) = twbtype(c(0));
 103   if (!(t(0) & A)) return -1;
 104
 105   /*
 106   // get c(-1), t(-1)
 107   */
 108   if (left >= 1) {
 109     c(-1) = lstr[-1];
 110     if (!th_isthai(c(-1))) return 0;
 111     t(-1) = twbtype(c(-1));
 112     if (!(t(-1) & A)) return 0; /* handle punctuation marks here */
 113   } else {
 114     c(-1) = 0;
 115     t(-1) = 0;
 116   }
 117
 118   /*
 119   // get c(1..2), t(1..2)
 120   */
 121   for (i = 1; i <= 2; i++) {
 122     if (i >= right) {
 123       c(i) = 0;
 124       t(i) = 0;
 125     } else {
 126       c(i) = rstr[i]; /* may be '\0'; */
 127       if (!th_isthai(c(i)))
 128         right = i--;
 129       else {
 130         t(i) = twbtype(c(i));
 131         if (!(t(i) & A)) right = i--;
 132       }
 133     }
 134   }
 135   /*
 136   // get c(-2..-3), t(-2..-3)
 137   */
 138   for (i = -2, j = -2; i >= -3; j--) {
 139     if (j < -left) {
 140       c(i) = 0;
 141       t(i) = 0;
 142       i--;
 143     } else {
 144       c(i) = lstr[j];
 145       if (!th_isthai(c(i)))
 146         left = 0;
 147       else {
 148         t(i) = (twb_t)(th_isthai(c(i)) ? twbtype(c(i)) : 0);
 149         if (!(t(i) & A))
 150           left = 0;
 151         else {
 152           if ((t(i + 1) & MT) && ((t(i) & VR) || (t(i + 2) & VR))) {
 153             c(i + 1) = c(i);
 154             t(i + 1) = t(i);
 155           } else
 156             i--;
 157         }
 158       }
 159     }
 160   }
 161
 162   /*
 163   // prohibit the unlikely
 164   */
 165   if ((t(-1) & C) && (t(0) & C)) {
 166     if ((t(-1) & CHE) || (t(0) & CHB)) return -1;
 167   }
 168   /*
 169   // special case : vlao, C/ sara_a|aa, !sara_a
 170   */
 171   if ((t(-3) & (VLA | VLO)) && (t(-2) & C) && (c(0) != TH_SARA_A) &&
 172       (c(-1) == TH_SARA_A || c(-0) == TH_SARA_AA))
 173     return 0;
 174
 175   /*
 176   // prohibit break
 177   */
 178   if (t(0) & NB) return -1;
 179   if (t(-1) & NE) return -1;
 180
 181   /*
 182         // apply 100% rules
 183   */
 184   if (t(-1) & VRE) {
 185     if (c(-2) == TH_SARA_AA && c(-1) == TH_SARA_A) return 0;
 186     return -1; /* usually too short syllable, part of word */
 187   }
 188
 189   if (t(-2) & VRE) return -1;
 190
 191   if ((t(0) & C) && (t(1) & (VR | MT)) &&
 192       (c(2) != TH_THANTHAKHAT)) {                              /*?C, NB */
 193     if ((t(-1) & (VRS | VRX)) && c(1) == TH_SARA_I) return -1; /* exception */
 194     if (t(-1) & (V | M)) return 0;                             /* !C/ C, NB */
 195     if (t(-2) & VRS) return 0;               /* VRS, C / C, NB */
 196     if (!(t(0) & C2) && c(1) == TH_SARA_I) { /* / !C2 or /c, sara_i */
 197       if (t(-2) & VRX) return 0;             /* VRX, C / C, NB ? 100%? */
 198       if (t(-2) & VC) return 0;              /* VC, C / C, NB ? 100% */
 199     }
 200   }
 201   if ((t(-1) & VRX) && (t(0) & CC)) return 0; /* VRX/ CC */
 202   if ((t(-2) & VRS) && (t(-1) & C) && (t(0) & (V | M)))
 203     return 0; /* VRS, C/ !C */
 204
 205   if ((t(0) & CX) && (t(1) & C2) && (c(2) != TH_THANTHAKHAT)) {
 206     if ((t(-2) & A) && (t(-1) & CX)) return 0;  /* A, CX / CX, C2 */
 207     if ((t(-2) & CX) && (t(-1) & MT)) return 0; /* CX, MT / CX, C2 */
 208   }
 209   /*
 210   // apply 90% rules
 211   */
 212   if (t(0) & VL) return 0;
 213   if (t(1) & VL) return -1;
 214   if (c(-1) == TH_THANTHAKHAT && c(-2) != TH_RORUA && c(-2) != TH_LOLING)
 215     return 0;
 216
 217   /*
 218   //return -1;
 219   // apply 80% rules
 220   */
 221   if (t(0) & CHE) {
 222     if ((t(-2) & VRS) && (t(-1) & C)) return 0; /* VRS, C/ CHE */
 223     /*if(t(-1) & VRX) return 0;                                 // VRX/ CHE */
 224     if (t(-1) & VC) return 0; /* VC/ CHE */
 225   }
 226   if (t(-1) & CHB) {
 227     if ((t(0) & C) && (t(1) & VR)) return 0; /* CHB/ CC, VR */
 228     if (t(0) & VC) return 0;                 /* CHB/ VC */
 229   }
 230
 231   if ((t(-2) & VL) && (t(1) & VR)) { /* VL, C? C, VR */
 232     if (t(-2) & VLI)
 233       return 0;                        /* VLI,C/C,VR .*/
 234     else {                             /* vlao, C ? C , VR */
 235       if (c(1) == TH_SARA_A) return 2; /* vlao, C, C, sara_a/ */
 236       if (t(-2) & VLO) return 0;       /* VLO, C/ C, !sara_a */
 237       if (!(t(1) & VRA)) return 0;     /* VLA, C/ C, !vca */
 238     }
 239   }
 240   /* C,MT,C */
 241   if ((t(-2) & C) && (t(-1) & MT) && (t(0) & CX)) return 1;
 242
 243   return -1;
 244 }
 245
 246 int TrbFollowing(const th_char* begin, int length, int offset)
 247 /*
 248 //(ThBreakIterator *this, int offset)
 249 */
 250 {
 251   const th_char* w = begin + offset;
 252   const th_char* end = begin + length;
 253   while (w < end && *w && !th_isthai(*w) && th_isspace(*w)) w++;
 254
 255   if (w < end && *w && !th_isthai(*w)) {
 256     int english = FALSE;
 257     while (w < end && *w && !th_isthai(*w) && !th_isspace(*w)) {
 258       if (th_isalpha(*w)) english = TRUE;
 259       w++;
 260     }
 261     if (english || w == end || (!th_isthai(*w) && th_isspace(*w)))
 262       return w - begin;
 263   }
 264   if (w == end || *w == 0 || !th_isthai(*w)) return w - begin;
 265   w++;
 266   if (w < end && *w && th_isthai(*w)) {
 267     int brk = TrbWordBreakPos(begin, w - begin, w, end - w);
 268     while (brk < 0) {
 269       w++;
 270       if (w == end || *w == 0 || !th_isthai(*w)) break;
 271       brk = TrbWordBreakPos(begin, w - begin, w, end - w);
 272     }
 273     if (brk > 0) w += brk;
 274   }
 275   if (w < end && *w && !th_isthai(*w)) {
 276     while (w < end && *w && !th_isthai(*w) && !th_isalpha(*w) &&
 277            !th_isspace(*w))
 278       w++;
 279   }
 280   return w - begin;
 281 }
 282
 283 /*
 284 /////////////////////////////////////////////////
 285 */
 286 const twb_t _TwbType[0x100 - 0xa0] = {
 287 #if 0
 288 /* 80  */     T,
 289 /* 81-8f */     0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 290 /* 90  */     T,
 291 /* 91-9f */     0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 292 #endif
 293     /* a0   */ 0,
 294     /* a1 ¡ */ CS,
 295     /* a2 ¢ */ CS | CHE,
 296     /* a3 £ */ CC | CHE,
 297     /* a4 € */ CS | CHE,
 298     /* a5 ¥ */ CC | CHE,
 299     /* a6 Š */ CS,
 300     /* a7 § */ CS | CHB,
 301     /* a8 š */ CS,
 302     /* a9 © */ CC | CHE,
 303     /* aa ª */ CS,
 304     /* ab « */ CC | CHE,
 305     /* ac ¬ */ CC | CHB | CHE,
 306     /* ad  */ CS | CHB,
 307     /* ae ® */ CS | CHB,
 308     /* af ¯ */ CS | CHB,
 309     /* b0 ° */ CS,
 310     /* b1 ± */ CS | CHB | CHE,
 311     /* b2 ² */ CS | CHB | CHE,
 312     /* b3 ³ */ CS | CHB,
 313     /* b4 Ž */ CS,
 314     /* b5 µ */ CS,
 315     /* b6 ¶ */ CS,
 316     /* b7 · */ CS,
 317     /* b8 ž */ CS,
 318     /* b9 ¹ */ CS,
 319     /* ba º */ CS,
 320     /* bb » */ CS,
 321     /* bc Œ */ CC | CHE,
 322     /* bd œ */ CC | CHE,
 323     /* be Ÿ */ CS,
 324     /* bf ¿ */ CS,
 325     /* c0 À */ CS | CHE,
 326     /* c1 Á */ CS,
 327     /* c2 Â */ CS,
 328     /* c3 Ã */ CS | C2 | CHE, /* ? add CHE  */
 329     /* c4 Ä */ VC | CHE,
 330     /* c5 Å */ CS | C2,
 331     /* c6 Æ */ VC | CHE,
 332     /* c7 Ç */ VC | C2,
 333     /* c8 È */ CS,
 334     /* c9 É */ CS | CHB,
 335     /* ca Ê */ CS | CHE,
 336     /* cb Ë */ CC | CHE,
 337     /* CC Ì */ CS | CHB | CHE,
 338     /* cd Í */ VC,
 339     /* ce Î */ CC | CHE,
 340     /* cf Ï */ T,
 341     /* d0 Ð */ VRE | VRA,
 342     /* d1  Ñ */ VRS,
 343     /* d2 Ò */ VRX | VRA,
 344     /* d3  Ó */ VRE,
 345     /* d4  Ô */ VRX | VRA,
 346     /* d5  Õ */ VRX | VRA,
 347     /* d6  Ö */ VRS,
 348     /* d7  × */ VRS | VRA,
 349     /* d8  Ø */ VRX,
 350     /* d9  Ù */ VRX,
 351     /* da  Ú */ T,
 352     /* db Û */ 0,
 353     /* dc Ü */ 0,
 354     /* dd Ý */ 0,
 355     /* de Þ */ 0,
 356     /* df ß */ T,
 357     /* e0 à */ VLA,
 358     /* e1 á */ VLO,
 359     /* e2 â */ VLO,
 360     /* e3 ã */ VLI,
 361     /* e4 ä */ VLI,
 362     /* e5 å */ VRE,
 363     /* e6 æ */ M,
 364     /* e7  ç */ M,
 365     /* e8  è */ M | MT,
 366     /* e9  é */ M | MT,
 367     /* ea  ê */ M | MT,
 368     /* eb  ë */ M | MT,
 369     /* ec  ì */ M,
 370     /* ed  í */ T,
 371     /* ee  î */ T,
 372     /* ef ï */ T,
 373     /* f0 ð */ T,
 374     /* f1 ñ */ T,
 375     /* f2 ò */ T,
 376     /* f3 ó */ T,
 377     /* f4 ô */ T,
 378     /* f5 õ */ T,
 379     /* f6 ö */ T,
 380     /* f7 ÷ */ T,
 381     /* f8 ø */ T,
 382     /* f9 ù */ T,
 383     /* fa ú */ T,
 384     /* fb û */ T,
 385     /* fc ü */ 0,
 386     /* fd ý */ 0,
 387     /* fe þ */ 0,
 388     /* ff  */ 0};