| /* |
| ******************************************************************************* |
| * |
| * Copyright (C) 1999-2009, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| * |
| ******************************************************************************* |
| * file name: utf8.h |
| * encoding: US-ASCII |
| * tab size: 8 (not used) |
| * indentation:4 |
| * |
| * created on: 1999sep13 |
| * created by: Markus W. Scherer |
| */ |
| |
| /** |
| * \file |
| * \brief C API: 8-bit Unicode handling macros |
| * |
| * This file defines macros to deal with 8-bit Unicode (UTF-8) code units (bytes) and strings. |
| * utf8.h is included by utf.h after unicode/umachine.h |
| * and some common definitions. |
| * |
| * For more information see utf.h and the ICU User Guide Strings chapter |
| * (http://icu-project.org/userguide/strings.html). |
| * |
| * <em>Usage:</em> |
| * ICU coding guidelines for if() statements should be followed when using these macros. |
| * Compound statements (curly braces {}) must be used for if-else-while... |
| * bodies and all macro statements should be terminated with semicolon. |
| */ |
| |
| #ifndef __UTF8_H__ |
| #define __UTF8_H__ |
| |
| /* utf.h must be included first. */ |
| #ifndef __UTF_H__ |
| # include "unicode/utf.h" |
| #endif |
| |
| /* internal definitions ----------------------------------------------------- */ |
| |
| /** |
| * \var utf8_countTrailBytes |
| * Internal array with numbers of trail bytes for any given byte used in |
| * lead byte position. |
| * |
| * This is internal since it is not meant to be called directly by external clients; |
| * however it is called by public macros in this file and thus must remain stable, |
| * and should not be hidden when other internal functions are hidden (otherwise |
| * public macros would fail to compile). |
| * @internal |
| */ |
| #ifdef U_UTF8_IMPL |
| U_EXPORT const uint8_t |
| #elif defined(U_STATIC_IMPLEMENTATION) || defined(U_COMMON_IMPLEMENTATION) |
| U_CFUNC const uint8_t |
| #else |
| U_CFUNC U_IMPORT const uint8_t /* U_IMPORT2? */ /*U_IMPORT*/ |
| #endif |
| utf8_countTrailBytes[256]; |
| |
| /** |
| * Count the trail bytes for a UTF-8 lead byte. |
| * |
| * This is internal since it is not meant to be called directly by external clients; |
| * however it is called by public macros in this file and thus must remain stable. |
| * @internal |
| */ |
| #define U8_COUNT_TRAIL_BYTES(leadByte) (utf8_countTrailBytes[(uint8_t)leadByte]) |
| |
| /** |
| * Mask a UTF-8 lead byte, leave only the lower bits that form part of the code point value. |
| * |
| * This is internal since it is not meant to be called directly by external clients; |
| * however it is called by public macros in this file and thus must remain stable. |
| * @internal |
| */ |
| #define U8_MASK_LEAD_BYTE(leadByte, countTrailBytes) ((leadByte)&=(1<<(6-(countTrailBytes)))-1) |
| |
| /** |
| * Function for handling "next code point" with error-checking. |
| * |
| * This is internal since it is not meant to be called directly by external clients; |
| * however it is U_STABLE (not U_INTERNAL) since it is called by public macros in this |
| * file and thus must remain stable, and should not be hidden when other internal |
| * functions are hidden (otherwise public macros would fail to compile). |
| * @internal |
| */ |
| U_STABLE UChar32 U_EXPORT2 |
| utf8_nextCharSafeBody(const uint8_t *s, int32_t *pi, int32_t length, UChar32 c, UBool strict); |
| |
| /** |
| * Function for handling "append code point" with error-checking. |
| * |
| * This is internal since it is not meant to be called directly by external clients; |
| * however it is U_STABLE (not U_INTERNAL) since it is called by public macros in this |
| * file and thus must remain stable, and should not be hidden when other internal |
| * functions are hidden (otherwise public macros would fail to compile). |
| * @internal |
| */ |
| U_STABLE int32_t U_EXPORT2 |
| utf8_appendCharSafeBody(uint8_t *s, int32_t i, int32_t length, UChar32 c, UBool *pIsError); |
| |
| /** |
| * Function for handling "previous code point" with error-checking. |
| * |
| * This is internal since it is not meant to be called directly by external clients; |
| * however it is U_STABLE (not U_INTERNAL) since it is called by public macros in this |
| * file and thus must remain stable, and should not be hidden when other internal |
| * functions are hidden (otherwise public macros would fail to compile). |
| * @internal |
| */ |
| U_STABLE UChar32 U_EXPORT2 |
| utf8_prevCharSafeBody(const uint8_t *s, int32_t start, int32_t *pi, UChar32 c, UBool strict); |
| |
| /** |
| * Function for handling "skip backward one code point" with error-checking. |
| * |
| * This is internal since it is not meant to be called directly by external clients; |
| * however it is U_STABLE (not U_INTERNAL) since it is called by public macros in this |
| * file and thus must remain stable, and should not be hidden when other internal |
| * functions are hidden (otherwise public macros would fail to compile). |
| * @internal |
| */ |
| U_STABLE int32_t U_EXPORT2 |
| utf8_back1SafeBody(const uint8_t *s, int32_t start, int32_t i); |
| |
| /* single-code point definitions -------------------------------------------- */ |
| |
| /** |
| * Does this code unit (byte) encode a code point by itself (US-ASCII 0..0x7f)? |
| * @param c 8-bit code unit (byte) |
| * @return TRUE or FALSE |
| * @stable ICU 2.4 |
| */ |
| #define U8_IS_SINGLE(c) (((c)&0x80)==0) |
| |
| /** |
| * Is this code unit (byte) a UTF-8 lead byte? |
| * @param c 8-bit code unit (byte) |
| * @return TRUE or FALSE |
| * @stable ICU 2.4 |
| */ |
| #define U8_IS_LEAD(c) ((uint8_t)((c)-0xc0)<0x3e) |
| |
| /** |
| * Is this code unit (byte) a UTF-8 trail byte? |
| * @param c 8-bit code unit (byte) |
| * @return TRUE or FALSE |
| * @stable ICU 2.4 |
| */ |
| #define U8_IS_TRAIL(c) (((c)&0xc0)==0x80) |
| |
| /** |
| * How many code units (bytes) are used for the UTF-8 encoding |
| * of this Unicode code point? |
| * @param c 32-bit code point |
| * @return 1..4, or 0 if c is a surrogate or not a Unicode code point |
| * @stable ICU 2.4 |
| */ |
| #define U8_LENGTH(c) \ |
| ((uint32_t)(c)<=0x7f ? 1 : \ |
| ((uint32_t)(c)<=0x7ff ? 2 : \ |
| ((uint32_t)(c)<=0xd7ff ? 3 : \ |
| ((uint32_t)(c)<=0xdfff || (uint32_t)(c)>0x10ffff ? 0 : \ |
| ((uint32_t)(c)<=0xffff ? 3 : 4)\ |
| ) \ |
| ) \ |
| ) \ |
| ) |
| |
| /** |
| * The maximum number of UTF-8 code units (bytes) per Unicode code point (U+0000..U+10ffff). |
| * @return 4 |
| * @stable ICU 2.4 |
| */ |
| #define U8_MAX_LENGTH 4 |
| |
| /** |
| * Get a code point from a string at a random-access offset, |
| * without changing the offset. |
| * The offset may point to either the lead byte or one of the trail bytes |
| * for a code point, in which case the macro will read all of the bytes |
| * for the code point. |
| * The result is undefined if the offset points to an illegal UTF-8 |
| * byte sequence. |
| * Iteration through a string is more efficient with U8_NEXT_UNSAFE or U8_NEXT. |
| * |
| * @param s const uint8_t * string |
| * @param i string offset |
| * @param c output UChar32 variable |
| * @see U8_GET |
| * @stable ICU 2.4 |
| */ |
| #define U8_GET_UNSAFE(s, i, c) { \ |
| int32_t _u8_get_unsafe_index=(int32_t)(i); \ |
| U8_SET_CP_START_UNSAFE(s, _u8_get_unsafe_index); \ |
| U8_NEXT_UNSAFE(s, _u8_get_unsafe_index, c); \ |
| } |
| |
| /** |
| * Get a code point from a string at a random-access offset, |
| * without changing the offset. |
| * The offset may point to either the lead byte or one of the trail bytes |
| * for a code point, in which case the macro will read all of the bytes |
| * for the code point. |
| * If the offset points to an illegal UTF-8 byte sequence, then |
| * c is set to a negative value. |
| * Iteration through a string is more efficient with U8_NEXT_UNSAFE or U8_NEXT. |
| * |
| * @param s const uint8_t * string |
| * @param start starting string offset |
| * @param i string offset, must be start<=i<length |
| * @param length string length |
| * @param c output UChar32 variable, set to <0 in case of an error |
| * @see U8_GET_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U8_GET(s, start, i, length, c) { \ |
| int32_t _u8_get_index=(int32_t)(i); \ |
| U8_SET_CP_START(s, start, _u8_get_index); \ |
| U8_NEXT(s, _u8_get_index, length, c); \ |
| } |
| |
| /* definitions with forward iteration --------------------------------------- */ |
| |
| /** |
| * Get a code point from a string at a code point boundary offset, |
| * and advance the offset to the next code point boundary. |
| * (Post-incrementing forward iteration.) |
| * "Unsafe" macro, assumes well-formed UTF-8. |
| * |
| * The offset may point to the lead byte of a multi-byte sequence, |
| * in which case the macro will read the whole sequence. |
| * The result is undefined if the offset points to a trail byte |
| * or an illegal UTF-8 sequence. |
| * |
| * @param s const uint8_t * string |
| * @param i string offset |
| * @param c output UChar32 variable |
| * @see U8_NEXT |
| * @stable ICU 2.4 |
| */ |
| #define U8_NEXT_UNSAFE(s, i, c) { \ |
| (c)=(uint8_t)(s)[(i)++]; \ |
| if((uint8_t)((c)-0xc0)<0x35) { \ |
| uint8_t __count=U8_COUNT_TRAIL_BYTES(c); \ |
| U8_MASK_LEAD_BYTE(c, __count); \ |
| switch(__count) { \ |
| /* each following branch falls through to the next one */ \ |
| case 3: \ |
| (c)=((c)<<6)|((s)[(i)++]&0x3f); \ |
| case 2: \ |
| (c)=((c)<<6)|((s)[(i)++]&0x3f); \ |
| case 1: \ |
| (c)=((c)<<6)|((s)[(i)++]&0x3f); \ |
| /* no other branches to optimize switch() */ \ |
| break; \ |
| } \ |
| } \ |
| } |
| |
| /** |
| * Get a code point from a string at a code point boundary offset, |
| * and advance the offset to the next code point boundary. |
| * (Post-incrementing forward iteration.) |
| * "Safe" macro, checks for illegal sequences and for string boundaries. |
| * |
| * The offset may point to the lead byte of a multi-byte sequence, |
| * in which case the macro will read the whole sequence. |
| * If the offset points to a trail byte or an illegal UTF-8 sequence, then |
| * c is set to a negative value. |
| * |
| * @param s const uint8_t * string |
| * @param i string offset, must be i<length |
| * @param length string length |
| * @param c output UChar32 variable, set to <0 in case of an error |
| * @see U8_NEXT_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U8_NEXT(s, i, length, c) { \ |
| (c)=(uint8_t)(s)[(i)++]; \ |
| if((c)>=0x80) { \ |
| uint8_t __t1, __t2; \ |
| if( /* handle U+1000..U+CFFF inline */ \ |
| (0xe0<(c) && (c)<=0xec) && \ |
| (((i)+1)<(length)) && \ |
| (__t1=(uint8_t)((s)[i]-0x80))<=0x3f && \ |
| (__t2=(uint8_t)((s)[(i)+1]-0x80))<= 0x3f \ |
| ) { \ |
| /* no need for (c&0xf) because the upper bits are truncated after <<12 in the cast to (UChar) */ \ |
| (c)=(UChar)(((c)<<12)|(__t1<<6)|__t2); \ |
| (i)+=2; \ |
| } else if( /* handle U+0080..U+07FF inline */ \ |
| ((c)<0xe0 && (c)>=0xc2) && \ |
| ((i)<(length)) && \ |
| (__t1=(uint8_t)((s)[i]-0x80))<=0x3f \ |
| ) { \ |
| (c)=(UChar)((((c)&0x1f)<<6)|__t1); \ |
| ++(i); \ |
| } else if(U8_IS_LEAD(c)) { \ |
| /* function call for "complicated" and error cases */ \ |
| (c)=utf8_nextCharSafeBody((const uint8_t *)s, &(i), (int32_t)(length), c, -1); \ |
| } else { \ |
| (c)=U_SENTINEL; \ |
| } \ |
| } \ |
| } |
| |
| /** |
| * Append a code point to a string, overwriting 1 to 4 bytes. |
| * The offset points to the current end of the string contents |
| * and is advanced (post-increment). |
| * "Unsafe" macro, assumes a valid code point and sufficient space in the string. |
| * Otherwise, the result is undefined. |
| * |
| * @param s const uint8_t * string buffer |
| * @param i string offset |
| * @param c code point to append |
| * @see U8_APPEND |
| * @stable ICU 2.4 |
| */ |
| #define U8_APPEND_UNSAFE(s, i, c) { \ |
| if((uint32_t)(c)<=0x7f) { \ |
| (s)[(i)++]=(uint8_t)(c); \ |
| } else { \ |
| if((uint32_t)(c)<=0x7ff) { \ |
| (s)[(i)++]=(uint8_t)(((c)>>6)|0xc0); \ |
| } else { \ |
| if((uint32_t)(c)<=0xffff) { \ |
| (s)[(i)++]=(uint8_t)(((c)>>12)|0xe0); \ |
| } else { \ |
| (s)[(i)++]=(uint8_t)(((c)>>18)|0xf0); \ |
| (s)[(i)++]=(uint8_t)((((c)>>12)&0x3f)|0x80); \ |
| } \ |
| (s)[(i)++]=(uint8_t)((((c)>>6)&0x3f)|0x80); \ |
| } \ |
| (s)[(i)++]=(uint8_t)(((c)&0x3f)|0x80); \ |
| } \ |
| } |
| |
| /** |
| * Append a code point to a string, overwriting 1 to 4 bytes. |
| * The offset points to the current end of the string contents |
| * and is advanced (post-increment). |
| * "Safe" macro, checks for a valid code point. |
| * If a non-ASCII code point is written, checks for sufficient space in the string. |
| * If the code point is not valid or trail bytes do not fit, |
| * then isError is set to TRUE. |
| * |
| * @param s const uint8_t * string buffer |
| * @param i string offset, must be i<capacity |
| * @param capacity size of the string buffer |
| * @param c code point to append |
| * @param isError output UBool set to TRUE if an error occurs, otherwise not modified |
| * @see U8_APPEND_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U8_APPEND(s, i, capacity, c, isError) { \ |
| if((uint32_t)(c)<=0x7f) { \ |
| (s)[(i)++]=(uint8_t)(c); \ |
| } else if((uint32_t)(c)<=0x7ff && (i)+1<(capacity)) { \ |
| (s)[(i)++]=(uint8_t)(((c)>>6)|0xc0); \ |
| (s)[(i)++]=(uint8_t)(((c)&0x3f)|0x80); \ |
| } else if((uint32_t)(c)<=0xd7ff && (i)+2<(capacity)) { \ |
| (s)[(i)++]=(uint8_t)(((c)>>12)|0xe0); \ |
| (s)[(i)++]=(uint8_t)((((c)>>6)&0x3f)|0x80); \ |
| (s)[(i)++]=(uint8_t)(((c)&0x3f)|0x80); \ |
| } else { \ |
| (i)=utf8_appendCharSafeBody(s, (int32_t)(i), (int32_t)(capacity), c, &(isError)); \ |
| } \ |
| } |
| |
| /** |
| * Advance the string offset from one code point boundary to the next. |
| * (Post-incrementing iteration.) |
| * "Unsafe" macro, assumes well-formed UTF-8. |
| * |
| * @param s const uint8_t * string |
| * @param i string offset |
| * @see U8_FWD_1 |
| * @stable ICU 2.4 |
| */ |
| #define U8_FWD_1_UNSAFE(s, i) { \ |
| (i)+=1+U8_COUNT_TRAIL_BYTES((s)[i]); \ |
| } |
| |
| /** |
| * Advance the string offset from one code point boundary to the next. |
| * (Post-incrementing iteration.) |
| * "Safe" macro, checks for illegal sequences and for string boundaries. |
| * |
| * @param s const uint8_t * string |
| * @param i string offset, must be i<length |
| * @param length string length |
| * @see U8_FWD_1_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U8_FWD_1(s, i, length) { \ |
| uint8_t __b=(uint8_t)(s)[(i)++]; \ |
| if(U8_IS_LEAD(__b)) { \ |
| uint8_t __count=U8_COUNT_TRAIL_BYTES(__b); \ |
| if((i)+__count>(length)) { \ |
| __count=(uint8_t)((length)-(i)); \ |
| } \ |
| while(__count>0 && U8_IS_TRAIL((s)[i])) { \ |
| ++(i); \ |
| --__count; \ |
| } \ |
| } \ |
| } |
| |
| /** |
| * Advance the string offset from one code point boundary to the n-th next one, |
| * i.e., move forward by n code points. |
| * (Post-incrementing iteration.) |
| * "Unsafe" macro, assumes well-formed UTF-8. |
| * |
| * @param s const uint8_t * string |
| * @param i string offset |
| * @param n number of code points to skip |
| * @see U8_FWD_N |
| * @stable ICU 2.4 |
| */ |
| #define U8_FWD_N_UNSAFE(s, i, n) { \ |
| int32_t __N=(n); \ |
| while(__N>0) { \ |
| U8_FWD_1_UNSAFE(s, i); \ |
| --__N; \ |
| } \ |
| } |
| |
| /** |
| * Advance the string offset from one code point boundary to the n-th next one, |
| * i.e., move forward by n code points. |
| * (Post-incrementing iteration.) |
| * "Safe" macro, checks for illegal sequences and for string boundaries. |
| * |
| * @param s const uint8_t * string |
| * @param i string offset, must be i<length |
| * @param length string length |
| * @param n number of code points to skip |
| * @see U8_FWD_N_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U8_FWD_N(s, i, length, n) { \ |
| int32_t __N=(n); \ |
| while(__N>0 && (i)<(length)) { \ |
| U8_FWD_1(s, i, length); \ |
| --__N; \ |
| } \ |
| } |
| |
| /** |
| * Adjust a random-access offset to a code point boundary |
| * at the start of a code point. |
| * If the offset points to a UTF-8 trail byte, |
| * then the offset is moved backward to the corresponding lead byte. |
| * Otherwise, it is not modified. |
| * "Unsafe" macro, assumes well-formed UTF-8. |
| * |
| * @param s const uint8_t * string |
| * @param i string offset |
| * @see U8_SET_CP_START |
| * @stable ICU 2.4 |
| */ |
| #define U8_SET_CP_START_UNSAFE(s, i) { \ |
| while(U8_IS_TRAIL((s)[i])) { --(i); } \ |
| } |
| |
| /** |
| * Adjust a random-access offset to a code point boundary |
| * at the start of a code point. |
| * If the offset points to a UTF-8 trail byte, |
| * then the offset is moved backward to the corresponding lead byte. |
| * Otherwise, it is not modified. |
| * "Safe" macro, checks for illegal sequences and for string boundaries. |
| * |
| * @param s const uint8_t * string |
| * @param start starting string offset (usually 0) |
| * @param i string offset, must be start<=i |
| * @see U8_SET_CP_START_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U8_SET_CP_START(s, start, i) { \ |
| if(U8_IS_TRAIL((s)[(i)])) { \ |
| (i)=utf8_back1SafeBody(s, start, (int32_t)(i)); \ |
| } \ |
| } |
| |
| /* definitions with backward iteration -------------------------------------- */ |
| |
| /** |
| * Move the string offset from one code point boundary to the previous one |
| * and get the code point between them. |
| * (Pre-decrementing backward iteration.) |
| * "Unsafe" macro, assumes well-formed UTF-8. |
| * |
| * The input offset may be the same as the string length. |
| * If the offset is behind a multi-byte sequence, then the macro will read |
| * the whole sequence. |
| * If the offset is behind a lead byte, then that itself |
| * will be returned as the code point. |
| * The result is undefined if the offset is behind an illegal UTF-8 sequence. |
| * |
| * @param s const uint8_t * string |
| * @param i string offset |
| * @param c output UChar32 variable |
| * @see U8_PREV |
| * @stable ICU 2.4 |
| */ |
| #define U8_PREV_UNSAFE(s, i, c) { \ |
| (c)=(uint8_t)(s)[--(i)]; \ |
| if(U8_IS_TRAIL(c)) { \ |
| uint8_t __b, __count=1, __shift=6; \ |
| \ |
| /* c is a trail byte */ \ |
| (c)&=0x3f; \ |
| for(;;) { \ |
| __b=(uint8_t)(s)[--(i)]; \ |
| if(__b>=0xc0) { \ |
| U8_MASK_LEAD_BYTE(__b, __count); \ |
| (c)|=(UChar32)__b<<__shift; \ |
| break; \ |
| } else { \ |
| (c)|=(UChar32)(__b&0x3f)<<__shift; \ |
| ++__count; \ |
| __shift+=6; \ |
| } \ |
| } \ |
| } \ |
| } |
| |
| /** |
| * Move the string offset from one code point boundary to the previous one |
| * and get the code point between them. |
| * (Pre-decrementing backward iteration.) |
| * "Safe" macro, checks for illegal sequences and for string boundaries. |
| * |
| * The input offset may be the same as the string length. |
| * If the offset is behind a multi-byte sequence, then the macro will read |
| * the whole sequence. |
| * If the offset is behind a lead byte, then that itself |
| * will be returned as the code point. |
| * If the offset is behind an illegal UTF-8 sequence, then c is set to a negative value. |
| * |
| * @param s const uint8_t * string |
| * @param start starting string offset (usually 0) |
| * @param i string offset, must be start<i |
| * @param c output UChar32 variable, set to <0 in case of an error |
| * @see U8_PREV_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U8_PREV(s, start, i, c) { \ |
| (c)=(uint8_t)(s)[--(i)]; \ |
| if((c)>=0x80) { \ |
| if((c)<=0xbf) { \ |
| (c)=utf8_prevCharSafeBody((const uint8_t *)s, start, &(i), c, -1); \ |
| } else { \ |
| (c)=U_SENTINEL; \ |
| } \ |
| } \ |
| } |
| |
| /** |
| * Move the string offset from one code point boundary to the previous one. |
| * (Pre-decrementing backward iteration.) |
| * The input offset may be the same as the string length. |
| * "Unsafe" macro, assumes well-formed UTF-8. |
| * |
| * @param s const uint8_t * string |
| * @param i string offset |
| * @see U8_BACK_1 |
| * @stable ICU 2.4 |
| */ |
| #define U8_BACK_1_UNSAFE(s, i) { \ |
| while(U8_IS_TRAIL((s)[--(i)])) {} \ |
| } |
| |
| /** |
| * Move the string offset from one code point boundary to the previous one. |
| * (Pre-decrementing backward iteration.) |
| * The input offset may be the same as the string length. |
| * "Safe" macro, checks for illegal sequences and for string boundaries. |
| * |
| * @param s const uint8_t * string |
| * @param start starting string offset (usually 0) |
| * @param i string offset, must be start<i |
| * @see U8_BACK_1_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U8_BACK_1(s, start, i) { \ |
| if(U8_IS_TRAIL((s)[--(i)])) { \ |
| (i)=utf8_back1SafeBody(s, start, (int32_t)(i)); \ |
| } \ |
| } |
| |
| /** |
| * Move the string offset from one code point boundary to the n-th one before it, |
| * i.e., move backward by n code points. |
| * (Pre-decrementing backward iteration.) |
| * The input offset may be the same as the string length. |
| * "Unsafe" macro, assumes well-formed UTF-8. |
| * |
| * @param s const uint8_t * string |
| * @param i string offset |
| * @param n number of code points to skip |
| * @see U8_BACK_N |
| * @stable ICU 2.4 |
| */ |
| #define U8_BACK_N_UNSAFE(s, i, n) { \ |
| int32_t __N=(n); \ |
| while(__N>0) { \ |
| U8_BACK_1_UNSAFE(s, i); \ |
| --__N; \ |
| } \ |
| } |
| |
| /** |
| * Move the string offset from one code point boundary to the n-th one before it, |
| * i.e., move backward by n code points. |
| * (Pre-decrementing backward iteration.) |
| * The input offset may be the same as the string length. |
| * "Safe" macro, checks for illegal sequences and for string boundaries. |
| * |
| * @param s const uint8_t * string |
| * @param start index of the start of the string |
| * @param i string offset, must be start<i |
| * @param n number of code points to skip |
| * @see U8_BACK_N_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U8_BACK_N(s, start, i, n) { \ |
| int32_t __N=(n); \ |
| while(__N>0 && (i)>(start)) { \ |
| U8_BACK_1(s, start, i); \ |
| --__N; \ |
| } \ |
| } |
| |
| /** |
| * Adjust a random-access offset to a code point boundary after a code point. |
| * If the offset is behind a partial multi-byte sequence, |
| * then the offset is incremented to behind the whole sequence. |
| * Otherwise, it is not modified. |
| * The input offset may be the same as the string length. |
| * "Unsafe" macro, assumes well-formed UTF-8. |
| * |
| * @param s const uint8_t * string |
| * @param i string offset |
| * @see U8_SET_CP_LIMIT |
| * @stable ICU 2.4 |
| */ |
| #define U8_SET_CP_LIMIT_UNSAFE(s, i) { \ |
| U8_BACK_1_UNSAFE(s, i); \ |
| U8_FWD_1_UNSAFE(s, i); \ |
| } |
| |
| /** |
| * Adjust a random-access offset to a code point boundary after a code point. |
| * If the offset is behind a partial multi-byte sequence, |
| * then the offset is incremented to behind the whole sequence. |
| * Otherwise, it is not modified. |
| * The input offset may be the same as the string length. |
| * "Safe" macro, checks for illegal sequences and for string boundaries. |
| * |
| * @param s const uint8_t * string |
| * @param start starting string offset (usually 0) |
| * @param i string offset, must be start<=i<=length |
| * @param length string length |
| * @see U8_SET_CP_LIMIT_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U8_SET_CP_LIMIT(s, start, i, length) { \ |
| if((start)<(i) && (i)<(length)) { \ |
| U8_BACK_1(s, start, i); \ |
| U8_FWD_1(s, i, length); \ |
| } \ |
| } |
| |
| #endif |