1 /* vi:set ts=8 sts=4 sw=4 noet: 2 * 3 * VIM - Vi IMproved by Bram Moolenaar 4 * 5 * Do ":help uganda" in Vim to read copying and usage conditions. 6 * Do ":help credits" in Vim to see a list of people who contributed. 7 * See README.txt for an overview of the Vim source code. 8 */ 9 10 /* 11 * arabic.c: functions for Arabic language 12 * 13 * Author: Nadim Shaikli & Isam Bayazidi 14 * Farsi support and restructuring to make adding new letters easier by Ali 15 * Gholami Rudi. Further work by Ameretat Reith. 16 */ 17 18 /* 19 * Sorted list of unicode Arabic characters. Each entry holds the 20 * presentation forms of a letter. 21 * 22 * Arabic characters are categorized into following types: 23 * 24 * Isolated - iso-8859-6 form 25 * Initial - unicode form-B start 26 * Medial - unicode form-B middle 27 * Final - unicode form-B final 28 * Stand-Alone - unicode form-B isolated 29 */ 30 31 #include "vim.h" 32 33 #if defined(FEAT_ARABIC) || defined(PROTO) 34 35 // Unicode values for Arabic characters. 36 #define a_HAMZA 0x0621 37 #define a_ALEF_MADDA 0x0622 38 #define a_ALEF_HAMZA_ABOVE 0x0623 39 #define a_WAW_HAMZA 0x0624 40 #define a_ALEF_HAMZA_BELOW 0x0625 41 #define a_YEH_HAMZA 0x0626 42 #define a_ALEF 0x0627 43 #define a_BEH 0x0628 44 #define a_TEH_MARBUTA 0x0629 45 #define a_TEH 0x062a 46 #define a_THEH 0x062b 47 #define a_JEEM 0x062c 48 #define a_HAH 0x062d 49 #define a_KHAH 0x062e 50 #define a_DAL 0x062f 51 #define a_THAL 0x0630 52 #define a_REH 0x0631 53 #define a_ZAIN 0x0632 54 #define a_SEEN 0x0633 55 #define a_SHEEN 0x0634 56 #define a_SAD 0x0635 57 #define a_DAD 0x0636 58 #define a_TAH 0x0637 59 #define a_ZAH 0x0638 60 #define a_AIN 0x0639 61 #define a_GHAIN 0x063a 62 #define a_TATWEEL 0x0640 63 #define a_FEH 0x0641 64 #define a_QAF 0x0642 65 #define a_KAF 0x0643 66 #define a_LAM 0x0644 67 #define a_MEEM 0x0645 68 #define a_NOON 0x0646 69 #define a_HEH 0x0647 70 #define a_WAW 0x0648 71 #define a_ALEF_MAKSURA 0x0649 72 #define a_YEH 0x064a 73 #define a_FATHATAN 0x064b 74 #define a_DAMMATAN 0x064c 75 #define a_KASRATAN 0x064d 76 #define a_FATHA 0x064e 77 #define a_DAMMA 0x064f 78 #define a_KASRA 0x0650 79 #define a_SHADDA 0x0651 80 #define a_SUKUN 0x0652 81 #define a_MADDA_ABOVE 0x0653 82 #define a_HAMZA_ABOVE 0x0654 83 #define a_HAMZA_BELOW 0x0655 84 85 #define a_PEH 0x067e 86 #define a_TCHEH 0x0686 87 #define a_JEH 0x0698 88 #define a_FKAF 0x06a9 89 #define a_GAF 0x06af 90 #define a_FYEH 0x06cc 91 92 #define a_s_LAM_ALEF_MADDA_ABOVE 0xfef5 93 #define a_f_LAM_ALEF_MADDA_ABOVE 0xfef6 94 #define a_s_LAM_ALEF_HAMZA_ABOVE 0xfef7 95 #define a_f_LAM_ALEF_HAMZA_ABOVE 0xfef8 96 #define a_s_LAM_ALEF_HAMZA_BELOW 0xfef9 97 #define a_f_LAM_ALEF_HAMZA_BELOW 0xfefa 98 #define a_s_LAM_ALEF 0xfefb 99 #define a_f_LAM_ALEF 0xfefc 100 101 static struct achar { 102 unsigned c; 103 unsigned isolated; 104 unsigned initial; 105 unsigned medial; 106 unsigned final; 107 } achars[] = { 108 {a_HAMZA, 0xfe80, 0, 0, 0}, 109 {a_ALEF_MADDA, 0xfe81, 0, 0, 0xfe82}, 110 {a_ALEF_HAMZA_ABOVE, 0xfe83, 0, 0, 0xfe84}, 111 {a_WAW_HAMZA, 0xfe85, 0, 0, 0xfe86}, 112 {a_ALEF_HAMZA_BELOW, 0xfe87, 0, 0, 0xfe88}, 113 {a_YEH_HAMZA, 0xfe89, 0xfe8b, 0xfe8c, 0xfe8a}, 114 {a_ALEF, 0xfe8d, 0, 0, 0xfe8e}, 115 {a_BEH, 0xfe8f, 0xfe91, 0xfe92, 0xfe90}, 116 {a_TEH_MARBUTA, 0xfe93, 0, 0, 0xfe94}, 117 {a_TEH, 0xfe95, 0xfe97, 0xfe98, 0xfe96}, 118 {a_THEH, 0xfe99, 0xfe9b, 0xfe9c, 0xfe9a}, 119 {a_JEEM, 0xfe9d, 0xfe9f, 0xfea0, 0xfe9e}, 120 {a_HAH, 0xfea1, 0xfea3, 0xfea4, 0xfea2}, 121 {a_KHAH, 0xfea5, 0xfea7, 0xfea8, 0xfea6}, 122 {a_DAL, 0xfea9, 0, 0, 0xfeaa}, 123 {a_THAL, 0xfeab, 0, 0, 0xfeac}, 124 {a_REH, 0xfead, 0, 0, 0xfeae}, 125 {a_ZAIN, 0xfeaf, 0, 0, 0xfeb0}, 126 {a_SEEN, 0xfeb1, 0xfeb3, 0xfeb4, 0xfeb2}, 127 {a_SHEEN, 0xfeb5, 0xfeb7, 0xfeb8, 0xfeb6}, 128 {a_SAD, 0xfeb9, 0xfebb, 0xfebc, 0xfeba}, 129 {a_DAD, 0xfebd, 0xfebf, 0xfec0, 0xfebe}, 130 {a_TAH, 0xfec1, 0xfec3, 0xfec4, 0xfec2}, 131 {a_ZAH, 0xfec5, 0xfec7, 0xfec8, 0xfec6}, 132 {a_AIN, 0xfec9, 0xfecb, 0xfecc, 0xfeca}, 133 {a_GHAIN, 0xfecd, 0xfecf, 0xfed0, 0xfece}, 134 {a_TATWEEL, 0, 0x0640, 0x0640, 0x0640}, 135 {a_FEH, 0xfed1, 0xfed3, 0xfed4, 0xfed2}, 136 {a_QAF, 0xfed5, 0xfed7, 0xfed8, 0xfed6}, 137 {a_KAF, 0xfed9, 0xfedb, 0xfedc, 0xfeda}, 138 {a_LAM, 0xfedd, 0xfedf, 0xfee0, 0xfede}, 139 {a_MEEM, 0xfee1, 0xfee3, 0xfee4, 0xfee2}, 140 {a_NOON, 0xfee5, 0xfee7, 0xfee8, 0xfee6}, 141 {a_HEH, 0xfee9, 0xfeeb, 0xfeec, 0xfeea}, 142 {a_WAW, 0xfeed, 0, 0, 0xfeee}, 143 {a_ALEF_MAKSURA, 0xfeef, 0, 0, 0xfef0}, 144 {a_YEH, 0xfef1, 0xfef3, 0xfef4, 0xfef2}, 145 {a_FATHATAN, 0xfe70, 0, 0, 0}, 146 {a_DAMMATAN, 0xfe72, 0, 0, 0}, 147 {a_KASRATAN, 0xfe74, 0, 0, 0}, 148 {a_FATHA, 0xfe76, 0, 0xfe77, 0}, 149 {a_DAMMA, 0xfe78, 0, 0xfe79, 0}, 150 {a_KASRA, 0xfe7a, 0, 0xfe7b, 0}, 151 {a_SHADDA, 0xfe7c, 0, 0xfe7c, 0}, 152 {a_SUKUN, 0xfe7e, 0, 0xfe7f, 0}, 153 {a_MADDA_ABOVE, 0, 0, 0, 0}, 154 {a_HAMZA_ABOVE, 0, 0, 0, 0}, 155 {a_HAMZA_BELOW, 0, 0, 0, 0}, 156 {a_PEH, 0xfb56, 0xfb58, 0xfb59, 0xfb57}, 157 {a_TCHEH, 0xfb7a, 0xfb7c, 0xfb7d, 0xfb7b}, 158 {a_JEH, 0xfb8a, 0, 0, 0xfb8b}, 159 {a_FKAF, 0xfb8e, 0xfb90, 0xfb91, 0xfb8f}, 160 {a_GAF, 0xfb92, 0xfb94, 0xfb95, 0xfb93}, 161 {a_FYEH, 0xfbfc, 0xfbfe, 0xfbff, 0xfbfd}, 162 }; 163 164 #define a_BYTE_ORDER_MARK 0xfeff 165 166 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0])) 167 168 /* 169 * Find the struct achar pointer to the given Arabic char. 170 * Returns NULL if not found. 171 */ 172 static struct achar * 173 find_achar(int c) 174 { 175 int h, m, l; 176 177 // using binary search to find c 178 h = ARRAY_SIZE(achars); 179 l = 0; 180 while (l < h) 181 { 182 m = (h + l) / 2; 183 if (achars[m].c == (unsigned)c) 184 return &achars[m]; 185 if ((unsigned)c < achars[m].c) 186 h = m; 187 else 188 l = m + 1; 189 } 190 return NULL; 191 } 192 193 /* 194 * Change shape - from Combination (2 char) to an Isolated 195 */ 196 static int 197 chg_c_laa2i(int hid_c) 198 { 199 int tempc; 200 201 switch (hid_c) 202 { 203 case a_ALEF_MADDA: 204 tempc = a_s_LAM_ALEF_MADDA_ABOVE; 205 break; 206 case a_ALEF_HAMZA_ABOVE: 207 tempc = a_s_LAM_ALEF_HAMZA_ABOVE; 208 break; 209 case a_ALEF_HAMZA_BELOW: 210 tempc = a_s_LAM_ALEF_HAMZA_BELOW; 211 break; 212 case a_ALEF: 213 tempc = a_s_LAM_ALEF; 214 break; 215 default: 216 tempc = 0; 217 } 218 219 return tempc; 220 } 221 222 /* 223 * Change shape - from Combination-Isolated to Final 224 */ 225 static int 226 chg_c_laa2f(int hid_c) 227 { 228 int tempc; 229 230 switch (hid_c) 231 { 232 case a_ALEF_MADDA: 233 tempc = a_f_LAM_ALEF_MADDA_ABOVE; 234 break; 235 case a_ALEF_HAMZA_ABOVE: 236 tempc = a_f_LAM_ALEF_HAMZA_ABOVE; 237 break; 238 case a_ALEF_HAMZA_BELOW: 239 tempc = a_f_LAM_ALEF_HAMZA_BELOW; 240 break; 241 case a_ALEF: 242 tempc = a_f_LAM_ALEF; 243 break; 244 default: 245 tempc = 0; 246 } 247 248 return tempc; 249 } 250 251 /* 252 * Returns whether it is possible to join the given letters 253 */ 254 static int 255 can_join(int c1, int c2) 256 { 257 struct achar *a1 = find_achar(c1); 258 struct achar *a2 = find_achar(c2); 259 260 return a1 && a2 && (a1->initial || a1->medial) && (a2->final || a2->medial); 261 } 262 263 /* 264 * Check whether we are dealing with a character that could be regarded as an 265 * Arabic combining character, need to check the character before this. 266 */ 267 int 268 arabic_maycombine(int two) 269 { 270 if (p_arshape && !p_tbidi) 271 return (two == a_ALEF_MADDA 272 || two == a_ALEF_HAMZA_ABOVE 273 || two == a_ALEF_HAMZA_BELOW 274 || two == a_ALEF); 275 return FALSE; 276 } 277 278 /* 279 * Check whether we are dealing with Arabic combining characters. 280 * Note: these are NOT really composing characters! 281 */ 282 int 283 arabic_combine( 284 int one, // first character 285 int two) // character just after "one" 286 { 287 if (one == a_LAM) 288 return arabic_maycombine(two); 289 return FALSE; 290 } 291 292 /* 293 * A_is_iso returns true if 'c' is an Arabic ISO-8859-6 character 294 * (alphabet/number/punctuation) 295 */ 296 static int 297 A_is_iso(int c) 298 { 299 return find_achar(c) != NULL; 300 } 301 302 /* 303 * A_is_ok returns true if 'c' is an Arabic 10646 (8859-6 or Form-B) 304 */ 305 static int 306 A_is_ok(int c) 307 { 308 return (A_is_iso(c) || c == a_BYTE_ORDER_MARK); 309 } 310 311 /* 312 * A_is_valid returns true if 'c' is an Arabic 10646 (8859-6 or Form-B) 313 * with some exceptions/exclusions 314 */ 315 static int 316 A_is_valid(int c) 317 { 318 return (A_is_ok(c) && c != a_HAMZA); 319 } 320 321 /* 322 * Do Arabic shaping on character "c". Returns the shaped character. 323 * out: "ccp" points to the first byte of the character to be shaped. 324 * in/out: "c1p" points to the first composing char for "c". 325 * in: "prev_c" is the previous character (not shaped) 326 * in: "prev_c1" is the first composing char for the previous char 327 * (not shaped) 328 * in: "next_c" is the next character (not shaped). 329 */ 330 int 331 arabic_shape( 332 int c, 333 int *ccp, 334 int *c1p, 335 int prev_c, 336 int prev_c1, 337 int next_c) 338 { 339 int curr_c; 340 int curr_laa; 341 int prev_laa; 342 343 // Deal only with Arabic characters, pass back all others 344 if (!A_is_ok(c)) 345 return c; 346 347 curr_laa = arabic_combine(c, *c1p); 348 prev_laa = arabic_combine(prev_c, prev_c1); 349 350 if (curr_laa) 351 { 352 if (A_is_valid(prev_c) && can_join(prev_c, a_LAM) && !prev_laa) 353 curr_c = chg_c_laa2f(*c1p); 354 else 355 curr_c = chg_c_laa2i(*c1p); 356 357 // Remove the composing character 358 *c1p = 0; 359 } 360 else 361 { 362 struct achar *curr_a = find_achar(c); 363 int backward_combine = !prev_laa && can_join(prev_c, c); 364 int forward_combine = can_join(c, next_c); 365 366 if (backward_combine) 367 { 368 if (forward_combine) 369 curr_c = curr_a->medial; 370 else 371 curr_c = curr_a->final; 372 } 373 else 374 { 375 if (forward_combine) 376 curr_c = curr_a->initial; 377 else 378 curr_c = curr_a->isolated; 379 } 380 } 381 382 // Character missing from the table means using original character. 383 if (curr_c == NUL) 384 curr_c = c; 385 386 if (curr_c != c && ccp != NULL) 387 { 388 char_u buf[MB_MAXBYTES + 1]; 389 390 // Update the first byte of the character. 391 (*mb_char2bytes)(curr_c, buf); 392 *ccp = buf[0]; 393 } 394 395 // Return the shaped character 396 return curr_c; 397 } 398 #endif // FEAT_ARABIC 399