base/third_party/icu/icu_utf.h

   1 /*
   2 *******************************************************************************
   3 *
   4 *   Copyright (C) 1999-2004, International Business Machines
   5 *   Corporation and others.  All Rights Reserved.
   6 *
   7 *******************************************************************************
   8 *   file name:  utf.h
   9 *   encoding:   US-ASCII
  10 *   tab size:   8 (not used)
  11 *   indentation:4
  12 *
  13 *   created on: 1999sep09
  14 *   created by: Markus W. Scherer
  15 */
  16
  17 #ifndef BASE_THIRD_PARTY_ICU_ICU_UTF_H_
  18 #define BASE_THIRD_PARTY_ICU_ICU_UTF_H_
  19
  20 #include "base/basictypes.h"
  21
  22 namespace base_icu {
  23
  24 typedef uint32 UChar32;
  25 typedef uint16 UChar;
  26 typedef int8 UBool;
  27
  28 // General ---------------------------------------------------------------------
  29 // from utf.h
  30
  31 /**
  32  * This value is intended for sentinel values for APIs that
  33  * (take or) return single code points (UChar32).
  34  * It is outside of the Unicode code point range 0..0x10ffff.
  35  *
  36  * For example, a "done" or "error" value in a new API
  37  * could be indicated with CBU_SENTINEL.
  38  *
  39  * ICU APIs designed before ICU 2.4 usually define service-specific "done"
  40  * values, mostly 0xffff.
  41  * Those may need to be distinguished from
  42  * actual U+ffff text contents by calling functions like
  43  * CharacterIterator::hasNext() or UnicodeString::length().
  44  *
  45  * @return -1
  46  * @see UChar32
  47  * @stable ICU 2.4
  48  */
  49 #define CBU_SENTINEL (-1)
  50
  51 /**
  52  * Is this code point a Unicode noncharacter?
  53  * @param c 32-bit code point
  54  * @return TRUE or FALSE
  55  * @stable ICU 2.4
  56  */
  57 #define CBU_IS_UNICODE_NONCHAR(c) \
  58     ((c)>=0xfdd0 && \
  59      ((uint32)(c)<=0xfdef || ((c)&0xfffe)==0xfffe) && \
  60      (uint32)(c)<=0x10ffff)
  61
  62 /**
  63  * Is c a Unicode code point value (0..U+10ffff)
  64  * that can be assigned a character?
  65  *
  66  * Code points that are not characters include:
  67  * - single surrogate code points (U+d800..U+dfff, 2048 code points)
  68  * - the last two code points on each plane (U+__fffe and U+__ffff, 34 code points)
  69  * - U+fdd0..U+fdef (new with Unicode 3.1, 32 code points)
  70  * - the highest Unicode code point value is U+10ffff
  71  *
  72  * This means that all code points below U+d800 are character code points,
  73  * and that boundary is tested first for performance.
  74  *
  75  * @param c 32-bit code point
  76  * @return TRUE or FALSE
  77  * @stable ICU 2.4
  78  */
  79 #define CBU_IS_UNICODE_CHAR(c) \
  80     ((uint32)(c)<0xd800 || \
  81         ((uint32)(c)>0xdfff && \
  82          (uint32)(c)<=0x10ffff && \
  83          !CBU_IS_UNICODE_NONCHAR(c)))
  84
  85 /**
  86  * Is this code point a surrogate (U+d800..U+dfff)?
  87  * @param c 32-bit code point
  88  * @return TRUE or FALSE
  89  * @stable ICU 2.4
  90  */
  91 #define CBU_IS_SURROGATE(c) (((c)&0xfffff800)==0xd800)
  92
  93 /**
  94  * Assuming c is a surrogate code point (U_IS_SURROGATE(c)),
  95  * is it a lead surrogate?
  96  * @param c 32-bit code point
  97  * @return TRUE or FALSE
  98  * @stable ICU 2.4
  99  */
 100 #define CBU_IS_SURROGATE_LEAD(c) (((c)&0x400)==0)
 101
 102
 103 // UTF-8 macros ----------------------------------------------------------------
 104 // from utf8.h
 105
 106 extern const uint8 utf8_countTrailBytes[256];
 107
 108 /**
 109  * Count the trail bytes for a UTF-8 lead byte.
 110  * @internal
 111  */
 112 #define CBU8_COUNT_TRAIL_BYTES(leadByte) (base_icu::utf8_countTrailBytes[(uint8)leadByte])
 113
 114 /**
 115  * Mask a UTF-8 lead byte, leave only the lower bits that form part of the code point value.
 116  * @internal
 117  */
 118 #define CBU8_MASK_LEAD_BYTE(leadByte, countTrailBytes) ((leadByte)&=(1<<(6-(countTrailBytes)))-1)
 119
 120 /**
 121  * Does this code unit (byte) encode a code point by itself (US-ASCII 0..0x7f)?
 122  * @param c 8-bit code unit (byte)
 123  * @return TRUE or FALSE
 124  * @stable ICU 2.4
 125  */
 126 #define CBU8_IS_SINGLE(c) (((c)&0x80)==0)
 127
 128 /**
 129  * Is this code unit (byte) a UTF-8 lead byte?
 130  * @param c 8-bit code unit (byte)
 131  * @return TRUE or FALSE
 132  * @stable ICU 2.4
 133  */
 134 #define CBU8_IS_LEAD(c) ((uint8)((c)-0xc0)<0x3e)
 135
 136 /**
 137  * Is this code unit (byte) a UTF-8 trail byte?
 138  * @param c 8-bit code unit (byte)
 139  * @return TRUE or FALSE
 140  * @stable ICU 2.4
 141  */
 142 #define CBU8_IS_TRAIL(c) (((c)&0xc0)==0x80)
 143
 144 /**
 145  * How many code units (bytes) are used for the UTF-8 encoding
 146  * of this Unicode code point?
 147  * @param c 32-bit code point
 148  * @return 1..4, or 0 if c is a surrogate or not a Unicode code point
 149  * @stable ICU 2.4
 150  */
 151 #define CBU8_LENGTH(c) \
 152     ((uint32)(c)<=0x7f ? 1 : \
 153         ((uint32)(c)<=0x7ff ? 2 : \
 154             ((uint32)(c)<=0xd7ff ? 3 : \
 155                 ((uint32)(c)<=0xdfff || (uint32)(c)>0x10ffff ? 0 : \
 156                     ((uint32)(c)<=0xffff ? 3 : 4)\
 157                 ) \
 158             ) \
 159         ) \
 160     )
 161
 162 /**
 163  * The maximum number of UTF-8 code units (bytes) per Unicode code point (U+0000..U+10ffff).
 164  * @return 4
 165  * @stable ICU 2.4
 166  */
 167 #define CBU8_MAX_LENGTH 4
 168
 169 /**
 170  * Function for handling "next code point" with error-checking.
 171  * @internal
 172  */
 173 UChar32 utf8_nextCharSafeBody(const uint8 *s, int32 *pi, int32 length, UChar32 c, UBool strict);
 174
 175 /**
 176  * Get a code point from a string at a code point boundary offset,
 177  * and advance the offset to the next code point boundary.
 178  * (Post-incrementing forward iteration.)
 179  * "Safe" macro, checks for illegal sequences and for string boundaries.
 180  *
 181  * The offset may point to the lead byte of a multi-byte sequence,
 182  * in which case the macro will read the whole sequence.
 183  * If the offset points to a trail byte or an illegal UTF-8 sequence, then
 184  * c is set to a negative value.
 185  *
 186  * @param s const uint8 * string
 187  * @param i string offset, i<length
 188  * @param length string length
 189  * @param c output UChar32 variable, set to <0 in case of an error
 190  * @see CBU8_NEXT_UNSAFE
 191  * @stable ICU 2.4
 192  */
 193 #define CBU8_NEXT(s, i, length, c) { \
 194     (c)=(s)[(i)++]; \
 195     if(((uint8)(c))>=0x80) { \
 196         if(CBU8_IS_LEAD(c)) { \
 197             (c)=base_icu::utf8_nextCharSafeBody((const uint8 *)s, &(i), (int32)(length), c, -1); \
 198         } else { \
 199             (c)=CBU_SENTINEL; \
 200         } \
 201     } \
 202 }
 203
 204 /**
 205  * Append a code point to a string, overwriting 1 to 4 bytes.
 206  * The offset points to the current end of the string contents
 207  * and is advanced (post-increment).
 208  * "Unsafe" macro, assumes a valid code point and sufficient space in the string.
 209  * Otherwise, the result is undefined.
 210  *
 211  * @param s const uint8 * string buffer
 212  * @param i string offset
 213  * @param c code point to append
 214  * @see CBU8_APPEND
 215  * @stable ICU 2.4
 216  */
 217 #define CBU8_APPEND_UNSAFE(s, i, c) { \
 218     if((uint32)(c)<=0x7f) { \
 219         (s)[(i)++]=(uint8)(c); \
 220     } else { \
 221         if((uint32)(c)<=0x7ff) { \
 222             (s)[(i)++]=(uint8)(((c)>>6)|0xc0); \
 223         } else { \
 224             if((uint32)(c)<=0xffff) { \
 225                 (s)[(i)++]=(uint8)(((c)>>12)|0xe0); \
 226             } else { \
 227                 (s)[(i)++]=(uint8)(((c)>>18)|0xf0); \
 228                 (s)[(i)++]=(uint8)((((c)>>12)&0x3f)|0x80); \
 229             } \
 230             (s)[(i)++]=(uint8)((((c)>>6)&0x3f)|0x80); \
 231         } \
 232         (s)[(i)++]=(uint8)(((c)&0x3f)|0x80); \
 233     } \
 234 }
 235
 236 // UTF-16 macros ---------------------------------------------------------------
 237 // from utf16.h
 238
 239 /**
 240  * Does this code unit alone encode a code point (BMP, not a surrogate)?
 241  * @param c 16-bit code unit
 242  * @return TRUE or FALSE
 243  * @stable ICU 2.4
 244  */
 245 #define CBU16_IS_SINGLE(c) !CBU_IS_SURROGATE(c)
 246
 247 /**
 248  * Is this code unit a lead surrogate (U+d800..U+dbff)?
 249  * @param c 16-bit code unit
 250  * @return TRUE or FALSE
 251  * @stable ICU 2.4
 252  */
 253 #define CBU16_IS_LEAD(c) (((c)&0xfffffc00)==0xd800)
 254
 255 /**
 256  * Is this code unit a trail surrogate (U+dc00..U+dfff)?
 257  * @param c 16-bit code unit
 258  * @return TRUE or FALSE
 259  * @stable ICU 2.4
 260  */
 261 #define CBU16_IS_TRAIL(c) (((c)&0xfffffc00)==0xdc00)
 262
 263 /**
 264  * Is this code unit a surrogate (U+d800..U+dfff)?
 265  * @param c 16-bit code unit
 266  * @return TRUE or FALSE
 267  * @stable ICU 2.4
 268  */
 269 #define CBU16_IS_SURROGATE(c) CBU_IS_SURROGATE(c)
 270
 271 /**
 272  * Assuming c is a surrogate code point (U16_IS_SURROGATE(c)),
 273  * is it a lead surrogate?
 274  * @param c 16-bit code unit
 275  * @return TRUE or FALSE
 276  * @stable ICU 2.4
 277  */
 278 #define CBU16_IS_SURROGATE_LEAD(c) (((c)&0x400)==0)
 279
 280 /**
 281  * Helper constant for CBU16_GET_SUPPLEMENTARY.
 282  * @internal
 283  */
 284 #define CBU16_SURROGATE_OFFSET ((0xd800<<10UL)+0xdc00-0x10000)
 285
 286 /**
 287  * Get a supplementary code point value (U+10000..U+10ffff)
 288  * from its lead and trail surrogates.
 289  * The result is undefined if the input values are not
 290  * lead and trail surrogates.
 291  *
 292  * @param lead lead surrogate (U+d800..U+dbff)
 293  * @param trail trail surrogate (U+dc00..U+dfff)
 294  * @return supplementary code point (U+10000..U+10ffff)
 295  * @stable ICU 2.4
 296  */
 297 #define CBU16_GET_SUPPLEMENTARY(lead, trail) \
 298     (((base_icu::UChar32)(lead)<<10UL)+(base_icu::UChar32)(trail)-CBU16_SURROGATE_OFFSET)
 299
 300
 301 /**
 302  * Get the lead surrogate (0xd800..0xdbff) for a
 303  * supplementary code point (0x10000..0x10ffff).
 304  * @param supplementary 32-bit code point (U+10000..U+10ffff)
 305  * @return lead surrogate (U+d800..U+dbff) for supplementary
 306  * @stable ICU 2.4
 307  */
 308 #define CBU16_LEAD(supplementary) \
 309     (base_icu::UChar)(((supplementary)>>10)+0xd7c0)
 310
 311 /**
 312  * Get the trail surrogate (0xdc00..0xdfff) for a
 313  * supplementary code point (0x10000..0x10ffff).
 314  * @param supplementary 32-bit code point (U+10000..U+10ffff)
 315  * @return trail surrogate (U+dc00..U+dfff) for supplementary
 316  * @stable ICU 2.4
 317  */
 318 #define CBU16_TRAIL(supplementary) \
 319     (base_icu::UChar)(((supplementary)&0x3ff)|0xdc00)
 320
 321 /**
 322  * How many 16-bit code units are used to encode this Unicode code point? (1 or 2)
 323  * The result is not defined if c is not a Unicode code point (U+0000..U+10ffff).
 324  * @param c 32-bit code point
 325  * @return 1 or 2
 326  * @stable ICU 2.4
 327  */
 328 #define CBU16_LENGTH(c) ((uint32)(c)<=0xffff ? 1 : 2)
 329
 330 /**
 331  * The maximum number of 16-bit code units per Unicode code point (U+0000..U+10ffff).
 332  * @return 2
 333  * @stable ICU 2.4
 334  */
 335 #define CBU16_MAX_LENGTH 2
 336
 337 /**
 338  * Get a code point from a string at a code point boundary offset,
 339  * and advance the offset to the next code point boundary.
 340  * (Post-incrementing forward iteration.)
 341  * "Safe" macro, handles unpaired surrogates and checks for string boundaries.
 342  *
 343  * The offset may point to the lead surrogate unit
 344  * for a supplementary code point, in which case the macro will read
 345  * the following trail surrogate as well.
 346  * If the offset points to a trail surrogate or
 347  * to a single, unpaired lead surrogate, then that itself
 348  * will be returned as the code point.
 349  *
 350  * @param s const UChar * string
 351  * @param i string offset, i<length
 352  * @param length string length
 353  * @param c output UChar32 variable
 354  * @stable ICU 2.4
 355  */
 356 #define CBU16_NEXT(s, i, length, c) { \
 357     (c)=(s)[(i)++]; \
 358     if(CBU16_IS_LEAD(c)) { \
 359         uint16 __c2; \
 360         if((i)<(length) && CBU16_IS_TRAIL(__c2=(s)[(i)])) { \
 361             ++(i); \
 362             (c)=CBU16_GET_SUPPLEMENTARY((c), __c2); \
 363         } \
 364     } \
 365 }
 366
 367 /**
 368  * Append a code point to a string, overwriting 1 or 2 code units.
 369  * The offset points to the current end of the string contents
 370  * and is advanced (post-increment).
 371  * "Unsafe" macro, assumes a valid code point and sufficient space in the string.
 372  * Otherwise, the result is undefined.
 373  *
 374  * @param s const UChar * string buffer
 375  * @param i string offset
 376  * @param c code point to append
 377  * @see CBU16_APPEND
 378  * @stable ICU 2.4
 379  */
 380 #define CBU16_APPEND_UNSAFE(s, i, c) { \
 381     if((uint32)(c)<=0xffff) { \
 382         (s)[(i)++]=(uint16)(c); \
 383     } else { \
 384         (s)[(i)++]=(uint16)(((c)>>10)+0xd7c0); \
 385         (s)[(i)++]=(uint16)(((c)&0x3ff)|0xdc00); \
 386     } \
 387 }
 388
 389 }  // namesapce base_icu
 390
 391 #endif  // BASE_THIRD_PARTY_ICU_ICU_UTF_H_