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