1 // Copyright (C) 2016 and later: Unicode, Inc. and others. 2 // License & terms of use: http://www.unicode.org/copyright.html 3 /* 4 ******************************************************************************* 5 * 6 * Copyright (C) 1999-2012, International Business Machines 7 * Corporation and others. All Rights Reserved. 8 * 9 ******************************************************************************* 10 * file name: utf16.h 11 * encoding: US-ASCII 12 * tab size: 8 (not used) 13 * indentation:4 14 * 15 * created on: 1999sep09 16 * created by: Markus W. Scherer 17 */ 18 19 /** 20 * \file 21 * \brief C API: 16-bit Unicode handling macros 22 * 23 * This file defines macros to deal with 16-bit Unicode (UTF-16) code units and strings. 24 * 25 * For more information see utf.h and the ICU User Guide Strings chapter 26 * (http://userguide.icu-project.org/strings). 27 * 28 * <em>Usage:</em> 29 * ICU coding guidelines for if() statements should be followed when using these macros. 30 * Compound statements (curly braces {}) must be used for if-else-while... 31 * bodies and all macro statements should be terminated with semicolon. 32 */ 33 34 #ifndef __UTF16_H__ 35 #define __UTF16_H__ 36 37 #include "unicode/umachine.h" 38 #ifndef __UTF_H__ 39 # include "unicode/utf.h" 40 #endif 41 42 /* single-code point definitions -------------------------------------------- */ 43 44 /** 45 * Does this code unit alone encode a code point (BMP, not a surrogate)? 46 * @param c 16-bit code unit 47 * @return TRUE or FALSE 48 * @stable ICU 2.4 49 */ 50 #define U16_IS_SINGLE(c) !U_IS_SURROGATE(c) 51 52 /** 53 * Is this code unit a lead surrogate (U+d800..U+dbff)? 54 * @param c 16-bit code unit 55 * @return TRUE or FALSE 56 * @stable ICU 2.4 57 */ 58 #define U16_IS_LEAD(c) (((c)&0xfffffc00)==0xd800) 59 60 /** 61 * Is this code unit a trail surrogate (U+dc00..U+dfff)? 62 * @param c 16-bit code unit 63 * @return TRUE or FALSE 64 * @stable ICU 2.4 65 */ 66 #define U16_IS_TRAIL(c) (((c)&0xfffffc00)==0xdc00) 67 68 /** 69 * Is this code unit a surrogate (U+d800..U+dfff)? 70 * @param c 16-bit code unit 71 * @return TRUE or FALSE 72 * @stable ICU 2.4 73 */ 74 #define U16_IS_SURROGATE(c) U_IS_SURROGATE(c) 75 76 /** 77 * Assuming c is a surrogate code point (U16_IS_SURROGATE(c)), 78 * is it a lead surrogate? 79 * @param c 16-bit code unit 80 * @return TRUE or FALSE 81 * @stable ICU 2.4 82 */ 83 #define U16_IS_SURROGATE_LEAD(c) (((c)&0x400)==0) 84 85 /** 86 * Assuming c is a surrogate code point (U16_IS_SURROGATE(c)), 87 * is it a trail surrogate? 88 * @param c 16-bit code unit 89 * @return TRUE or FALSE 90 * @stable ICU 4.2 91 */ 92 #define U16_IS_SURROGATE_TRAIL(c) (((c)&0x400)!=0) 93 94 /** 95 * Helper constant for U16_GET_SUPPLEMENTARY. 96 * @internal 97 */ 98 #define U16_SURROGATE_OFFSET ((0xd800<<10UL)+0xdc00-0x10000) 99 100 /** 101 * Get a supplementary code point value (U+10000..U+10ffff) 102 * from its lead and trail surrogates. 103 * The result is undefined if the input values are not 104 * lead and trail surrogates. 105 * 106 * @param lead lead surrogate (U+d800..U+dbff) 107 * @param trail trail surrogate (U+dc00..U+dfff) 108 * @return supplementary code point (U+10000..U+10ffff) 109 * @stable ICU 2.4 110 */ 111 #define U16_GET_SUPPLEMENTARY(lead, trail) \ 112 (((UChar32)(lead)<<10UL)+(UChar32)(trail)-U16_SURROGATE_OFFSET) 113 114 115 /** 116 * Get the lead surrogate (0xd800..0xdbff) for a 117 * supplementary code point (0x10000..0x10ffff). 118 * @param supplementary 32-bit code point (U+10000..U+10ffff) 119 * @return lead surrogate (U+d800..U+dbff) for supplementary 120 * @stable ICU 2.4 121 */ 122 #define U16_LEAD(supplementary) (UChar)(((supplementary)>>10)+0xd7c0) 123 124 /** 125 * Get the trail surrogate (0xdc00..0xdfff) for a 126 * supplementary code point (0x10000..0x10ffff). 127 * @param supplementary 32-bit code point (U+10000..U+10ffff) 128 * @return trail surrogate (U+dc00..U+dfff) for supplementary 129 * @stable ICU 2.4 130 */ 131 #define U16_TRAIL(supplementary) (UChar)(((supplementary)&0x3ff)|0xdc00) 132 133 /** 134 * How many 16-bit code units are used to encode this Unicode code point? (1 or 2) 135 * The result is not defined if c is not a Unicode code point (U+0000..U+10ffff). 136 * @param c 32-bit code point 137 * @return 1 or 2 138 * @stable ICU 2.4 139 */ 140 #define U16_LENGTH(c) ((uint32_t)(c)<=0xffff ? 1 : 2) 141 142 /** 143 * The maximum number of 16-bit code units per Unicode code point (U+0000..U+10ffff). 144 * @return 2 145 * @stable ICU 2.4 146 */ 147 #define U16_MAX_LENGTH 2 148 149 /** 150 * Get a code point from a string at a random-access offset, 151 * without changing the offset. 152 * "Unsafe" macro, assumes well-formed UTF-16. 153 * 154 * The offset may point to either the lead or trail surrogate unit 155 * for a supplementary code point, in which case the macro will read 156 * the adjacent matching surrogate as well. 157 * The result is undefined if the offset points to a single, unpaired surrogate. 158 * Iteration through a string is more efficient with U16_NEXT_UNSAFE or U16_NEXT. 159 * 160 * @param s const UChar * string 161 * @param i string offset 162 * @param c output UChar32 variable 163 * @see U16_GET 164 * @stable ICU 2.4 165 */ 166 #define U16_GET_UNSAFE(s, i, c) { \ 167 (c)=(s)[i]; \ 168 if(U16_IS_SURROGATE(c)) { \ 169 if(U16_IS_SURROGATE_LEAD(c)) { \ 170 (c)=U16_GET_SUPPLEMENTARY((c), (s)[(i)+1]); \ 171 } else { \ 172 (c)=U16_GET_SUPPLEMENTARY((s)[(i)-1], (c)); \ 173 } \ 174 } \ 175 } 176 177 /** 178 * Get a code point from a string at a random-access offset, 179 * without changing the offset. 180 * "Safe" macro, handles unpaired surrogates and checks for string boundaries. 181 * 182 * The offset may point to either the lead or trail surrogate unit 183 * for a supplementary code point, in which case the macro will read 184 * the adjacent matching surrogate as well. 185 * 186 * The length can be negative for a NUL-terminated string. 187 * 188 * If the offset points to a single, unpaired surrogate, then that itself 189 * will be returned as the code point. 190 * Iteration through a string is more efficient with U16_NEXT_UNSAFE or U16_NEXT. 191 * 192 * @param s const UChar * string 193 * @param start starting string offset (usually 0) 194 * @param i string offset, must be start<=i<length 195 * @param length string length 196 * @param c output UChar32 variable 197 * @see U16_GET_UNSAFE 198 * @stable ICU 2.4 199 */ 200 #define U16_GET(s, start, i, length, c) { \ 201 (c)=(s)[i]; \ 202 if(U16_IS_SURROGATE(c)) { \ 203 uint16_t __c2; \ 204 if(U16_IS_SURROGATE_LEAD(c)) { \ 205 if((i)+1!=(length) && U16_IS_TRAIL(__c2=(s)[(i)+1])) { \ 206 (c)=U16_GET_SUPPLEMENTARY((c), __c2); \ 207 } \ 208 } else { \ 209 if((i)>(start) && U16_IS_LEAD(__c2=(s)[(i)-1])) { \ 210 (c)=U16_GET_SUPPLEMENTARY(__c2, (c)); \ 211 } \ 212 } \ 213 } \ 214 } 215 216 /* definitions with forward iteration --------------------------------------- */ 217 218 /** 219 * Get a code point from a string at a code point boundary offset, 220 * and advance the offset to the next code point boundary. 221 * (Post-incrementing forward iteration.) 222 * "Unsafe" macro, assumes well-formed UTF-16. 223 * 224 * The offset may point to the lead surrogate unit 225 * for a supplementary code point, in which case the macro will read 226 * the following trail surrogate as well. 227 * If the offset points to a trail surrogate, then that itself 228 * will be returned as the code point. 229 * The result is undefined if the offset points to a single, unpaired lead surrogate. 230 * 231 * @param s const UChar * string 232 * @param i string offset 233 * @param c output UChar32 variable 234 * @see U16_NEXT 235 * @stable ICU 2.4 236 */ 237 #define U16_NEXT_UNSAFE(s, i, c) { \ 238 (c)=(s)[(i)++]; \ 239 if(U16_IS_LEAD(c)) { \ 240 (c)=U16_GET_SUPPLEMENTARY((c), (s)[(i)++]); \ 241 } \ 242 } 243 244 /** 245 * Get a code point from a string at a code point boundary offset, 246 * and advance the offset to the next code point boundary. 247 * (Post-incrementing forward iteration.) 248 * "Safe" macro, handles unpaired surrogates and checks for string boundaries. 249 * 250 * The length can be negative for a NUL-terminated string. 251 * 252 * The offset may point to the lead surrogate unit 253 * for a supplementary code point, in which case the macro will read 254 * the following trail surrogate as well. 255 * If the offset points to a trail surrogate or 256 * to a single, unpaired lead surrogate, then that itself 257 * will be returned as the code point. 258 * 259 * @param s const UChar * string 260 * @param i string offset, must be i<length 261 * @param length string length 262 * @param c output UChar32 variable 263 * @see U16_NEXT_UNSAFE 264 * @stable ICU 2.4 265 */ 266 #define U16_NEXT(s, i, length, c) { \ 267 (c)=(s)[(i)++]; \ 268 if(U16_IS_LEAD(c)) { \ 269 uint16_t __c2; \ 270 if((i)!=(length) && U16_IS_TRAIL(__c2=(s)[(i)])) { \ 271 ++(i); \ 272 (c)=U16_GET_SUPPLEMENTARY((c), __c2); \ 273 } \ 274 } \ 275 } 276 277 /** 278 * Append a code point to a string, overwriting 1 or 2 code units. 279 * The offset points to the current end of the string contents 280 * and is advanced (post-increment). 281 * "Unsafe" macro, assumes a valid code point and sufficient space in the string. 282 * Otherwise, the result is undefined. 283 * 284 * @param s const UChar * string buffer 285 * @param i string offset 286 * @param c code point to append 287 * @see U16_APPEND 288 * @stable ICU 2.4 289 */ 290 #define U16_APPEND_UNSAFE(s, i, c) { \ 291 if((uint32_t)(c)<=0xffff) { \ 292 (s)[(i)++]=(uint16_t)(c); \ 293 } else { \ 294 (s)[(i)++]=(uint16_t)(((c)>>10)+0xd7c0); \ 295 (s)[(i)++]=(uint16_t)(((c)&0x3ff)|0xdc00); \ 296 } \ 297 } 298 299 /** 300 * Append a code point to a string, overwriting 1 or 2 code units. 301 * The offset points to the current end of the string contents 302 * and is advanced (post-increment). 303 * "Safe" macro, checks for a valid code point. 304 * If a surrogate pair is written, checks for sufficient space in the string. 305 * If the code point is not valid or a trail surrogate does not fit, 306 * then isError is set to TRUE. 307 * 308 * @param s const UChar * string buffer 309 * @param i string offset, must be i<capacity 310 * @param capacity size of the string buffer 311 * @param c code point to append 312 * @param isError output UBool set to TRUE if an error occurs, otherwise not modified 313 * @see U16_APPEND_UNSAFE 314 * @stable ICU 2.4 315 */ 316 #define U16_APPEND(s, i, capacity, c, isError) { \ 317 if((uint32_t)(c)<=0xffff) { \ 318 (s)[(i)++]=(uint16_t)(c); \ 319 } else if((uint32_t)(c)<=0x10ffff && (i)+1<(capacity)) { \ 320 (s)[(i)++]=(uint16_t)(((c)>>10)+0xd7c0); \ 321 (s)[(i)++]=(uint16_t)(((c)&0x3ff)|0xdc00); \ 322 } else /* c>0x10ffff or not enough space */ { \ 323 (isError)=TRUE; \ 324 } \ 325 } 326 327 /** 328 * Advance the string offset from one code point boundary to the next. 329 * (Post-incrementing iteration.) 330 * "Unsafe" macro, assumes well-formed UTF-16. 331 * 332 * @param s const UChar * string 333 * @param i string offset 334 * @see U16_FWD_1 335 * @stable ICU 2.4 336 */ 337 #define U16_FWD_1_UNSAFE(s, i) { \ 338 if(U16_IS_LEAD((s)[(i)++])) { \ 339 ++(i); \ 340 } \ 341 } 342 343 /** 344 * Advance the string offset from one code point boundary to the next. 345 * (Post-incrementing iteration.) 346 * "Safe" macro, handles unpaired surrogates and checks for string boundaries. 347 * 348 * The length can be negative for a NUL-terminated string. 349 * 350 * @param s const UChar * string 351 * @param i string offset, must be i<length 352 * @param length string length 353 * @see U16_FWD_1_UNSAFE 354 * @stable ICU 2.4 355 */ 356 #define U16_FWD_1(s, i, length) { \ 357 if(U16_IS_LEAD((s)[(i)++]) && (i)!=(length) && U16_IS_TRAIL((s)[i])) { \ 358 ++(i); \ 359 } \ 360 } 361 362 /** 363 * Advance the string offset from one code point boundary to the n-th next one, 364 * i.e., move forward by n code points. 365 * (Post-incrementing iteration.) 366 * "Unsafe" macro, assumes well-formed UTF-16. 367 * 368 * @param s const UChar * string 369 * @param i string offset 370 * @param n number of code points to skip 371 * @see U16_FWD_N 372 * @stable ICU 2.4 373 */ 374 #define U16_FWD_N_UNSAFE(s, i, n) { \ 375 int32_t __N=(n); \ 376 while(__N>0) { \ 377 U16_FWD_1_UNSAFE(s, i); \ 378 --__N; \ 379 } \ 380 } 381 382 /** 383 * Advance the string offset from one code point boundary to the n-th next one, 384 * i.e., move forward by n code points. 385 * (Post-incrementing iteration.) 386 * "Safe" macro, handles unpaired surrogates and checks for string boundaries. 387 * 388 * The length can be negative for a NUL-terminated string. 389 * 390 * @param s const UChar * string 391 * @param i int32_t string offset, must be i<length 392 * @param length int32_t string length 393 * @param n number of code points to skip 394 * @see U16_FWD_N_UNSAFE 395 * @stable ICU 2.4 396 */ 397 #define U16_FWD_N(s, i, length, n) { \ 398 int32_t __N=(n); \ 399 while(__N>0 && ((i)<(length) || ((length)<0 && (s)[i]!=0))) { \ 400 U16_FWD_1(s, i, length); \ 401 --__N; \ 402 } \ 403 } 404 405 /** 406 * Adjust a random-access offset to a code point boundary 407 * at the start of a code point. 408 * If the offset points to the trail surrogate of a surrogate pair, 409 * then the offset is decremented. 410 * Otherwise, it is not modified. 411 * "Unsafe" macro, assumes well-formed UTF-16. 412 * 413 * @param s const UChar * string 414 * @param i string offset 415 * @see U16_SET_CP_START 416 * @stable ICU 2.4 417 */ 418 #define U16_SET_CP_START_UNSAFE(s, i) { \ 419 if(U16_IS_TRAIL((s)[i])) { \ 420 --(i); \ 421 } \ 422 } 423 424 /** 425 * Adjust a random-access offset to a code point boundary 426 * at the start of a code point. 427 * If the offset points to the trail surrogate of a surrogate pair, 428 * then the offset is decremented. 429 * Otherwise, it is not modified. 430 * "Safe" macro, handles unpaired surrogates and checks for string boundaries. 431 * 432 * @param s const UChar * string 433 * @param start starting string offset (usually 0) 434 * @param i string offset, must be start<=i 435 * @see U16_SET_CP_START_UNSAFE 436 * @stable ICU 2.4 437 */ 438 #define U16_SET_CP_START(s, start, i) { \ 439 if(U16_IS_TRAIL((s)[i]) && (i)>(start) && U16_IS_LEAD((s)[(i)-1])) { \ 440 --(i); \ 441 } \ 442 } 443 444 /* definitions with backward iteration -------------------------------------- */ 445 446 /** 447 * Move the string offset from one code point boundary to the previous one 448 * and get the code point between them. 449 * (Pre-decrementing backward iteration.) 450 * "Unsafe" macro, assumes well-formed UTF-16. 451 * 452 * The input offset may be the same as the string length. 453 * If the offset is behind a trail surrogate unit 454 * for a supplementary code point, then the macro will read 455 * the preceding lead surrogate as well. 456 * If the offset is behind a lead surrogate, then that itself 457 * will be returned as the code point. 458 * The result is undefined if the offset is behind a single, unpaired trail surrogate. 459 * 460 * @param s const UChar * string 461 * @param i string offset 462 * @param c output UChar32 variable 463 * @see U16_PREV 464 * @stable ICU 2.4 465 */ 466 #define U16_PREV_UNSAFE(s, i, c) { \ 467 (c)=(s)[--(i)]; \ 468 if(U16_IS_TRAIL(c)) { \ 469 (c)=U16_GET_SUPPLEMENTARY((s)[--(i)], (c)); \ 470 } \ 471 } 472 473 /** 474 * Move the string offset from one code point boundary to the previous one 475 * and get the code point between them. 476 * (Pre-decrementing backward iteration.) 477 * "Safe" macro, handles unpaired surrogates and checks for string boundaries. 478 * 479 * The input offset may be the same as the string length. 480 * If the offset is behind a trail surrogate unit 481 * for a supplementary code point, then the macro will read 482 * the preceding lead surrogate as well. 483 * If the offset is behind a lead surrogate or behind a single, unpaired 484 * trail surrogate, then that itself 485 * will be returned as the code point. 486 * 487 * @param s const UChar * string 488 * @param start starting string offset (usually 0) 489 * @param i string offset, must be start<i 490 * @param c output UChar32 variable 491 * @see U16_PREV_UNSAFE 492 * @stable ICU 2.4 493 */ 494 #define U16_PREV(s, start, i, c) { \ 495 (c)=(s)[--(i)]; \ 496 if(U16_IS_TRAIL(c)) { \ 497 uint16_t __c2; \ 498 if((i)>(start) && U16_IS_LEAD(__c2=(s)[(i)-1])) { \ 499 --(i); \ 500 (c)=U16_GET_SUPPLEMENTARY(__c2, (c)); \ 501 } \ 502 } \ 503 } 504 505 /** 506 * Move the string offset from one code point boundary to the previous one. 507 * (Pre-decrementing backward iteration.) 508 * The input offset may be the same as the string length. 509 * "Unsafe" macro, assumes well-formed UTF-16. 510 * 511 * @param s const UChar * string 512 * @param i string offset 513 * @see U16_BACK_1 514 * @stable ICU 2.4 515 */ 516 #define U16_BACK_1_UNSAFE(s, i) { \ 517 if(U16_IS_TRAIL((s)[--(i)])) { \ 518 --(i); \ 519 } \ 520 } 521 522 /** 523 * Move the string offset from one code point boundary to the previous one. 524 * (Pre-decrementing backward iteration.) 525 * The input offset may be the same as the string length. 526 * "Safe" macro, handles unpaired surrogates and checks for string boundaries. 527 * 528 * @param s const UChar * string 529 * @param start starting string offset (usually 0) 530 * @param i string offset, must be start<i 531 * @see U16_BACK_1_UNSAFE 532 * @stable ICU 2.4 533 */ 534 #define U16_BACK_1(s, start, i) { \ 535 if(U16_IS_TRAIL((s)[--(i)]) && (i)>(start) && U16_IS_LEAD((s)[(i)-1])) { \ 536 --(i); \ 537 } \ 538 } 539 540 /** 541 * Move the string offset from one code point boundary to the n-th one before it, 542 * i.e., move backward by n code points. 543 * (Pre-decrementing backward iteration.) 544 * The input offset may be the same as the string length. 545 * "Unsafe" macro, assumes well-formed UTF-16. 546 * 547 * @param s const UChar * string 548 * @param i string offset 549 * @param n number of code points to skip 550 * @see U16_BACK_N 551 * @stable ICU 2.4 552 */ 553 #define U16_BACK_N_UNSAFE(s, i, n) { \ 554 int32_t __N=(n); \ 555 while(__N>0) { \ 556 U16_BACK_1_UNSAFE(s, i); \ 557 --__N; \ 558 } \ 559 } 560 561 /** 562 * Move the string offset from one code point boundary to the n-th one before it, 563 * i.e., move backward by n code points. 564 * (Pre-decrementing backward iteration.) 565 * The input offset may be the same as the string length. 566 * "Safe" macro, handles unpaired surrogates and checks for string boundaries. 567 * 568 * @param s const UChar * string 569 * @param start start of string 570 * @param i string offset, must be start<i 571 * @param n number of code points to skip 572 * @see U16_BACK_N_UNSAFE 573 * @stable ICU 2.4 574 */ 575 #define U16_BACK_N(s, start, i, n) { \ 576 int32_t __N=(n); \ 577 while(__N>0 && (i)>(start)) { \ 578 U16_BACK_1(s, start, i); \ 579 --__N; \ 580 } \ 581 } 582 583 /** 584 * Adjust a random-access offset to a code point boundary after a code point. 585 * If the offset is behind the lead surrogate of a surrogate pair, 586 * then the offset is incremented. 587 * Otherwise, it is not modified. 588 * The input offset may be the same as the string length. 589 * "Unsafe" macro, assumes well-formed UTF-16. 590 * 591 * @param s const UChar * string 592 * @param i string offset 593 * @see U16_SET_CP_LIMIT 594 * @stable ICU 2.4 595 */ 596 #define U16_SET_CP_LIMIT_UNSAFE(s, i) { \ 597 if(U16_IS_LEAD((s)[(i)-1])) { \ 598 ++(i); \ 599 } \ 600 } 601 602 /** 603 * Adjust a random-access offset to a code point boundary after a code point. 604 * If the offset is behind the lead surrogate of a surrogate pair, 605 * then the offset is incremented. 606 * Otherwise, it is not modified. 607 * The input offset may be the same as the string length. 608 * "Safe" macro, handles unpaired surrogates and checks for string boundaries. 609 * 610 * The length can be negative for a NUL-terminated string. 611 * 612 * @param s const UChar * string 613 * @param start int32_t starting string offset (usually 0) 614 * @param i int32_t string offset, start<=i<=length 615 * @param length int32_t string length 616 * @see U16_SET_CP_LIMIT_UNSAFE 617 * @stable ICU 2.4 618 */ 619 #define U16_SET_CP_LIMIT(s, start, i, length) { \ 620 if((start)<(i) && ((i)<(length) || (length)<0) && U16_IS_LEAD((s)[(i)-1]) && U16_IS_TRAIL((s)[i])) { \ 621 ++(i); \ 622 } \ 623 } 624 625 #endif 626