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utf8.h File Reference

C API: 8-bit Unicode handling macros. More...

#include "unicode/utf.h"

Go to the source code of this file.

Defines

#define U8_COUNT_TRAIL_BYTES(leadByte)   (utf8_countTrailBytes[(uint8_t)leadByte])
 Count the trail bytes for a UTF-8 lead byte. More...

#define U8_MASK_LEAD_BYTE(leadByte, countTrailBytes)   ((leadByte)&=(1<<(6-(countTrailBytes)))-1)
 Mask a UTF-8 lead byte, leave only the lower bits that form part of the code point value. More...

#define U8_IS_SINGLE(c)   (((c)&0x80)==0)
 Does this code unit (byte) encode a code point by itself (US-ASCII 0..0x7f)? More...

#define U8_IS_LEAD(c)   ((uint8_t)((c)-0xc0)<0x3e)
 Is this code unit (byte) a UTF-8 lead byte? More...

#define U8_IS_TRAIL(c)   (((c)&0xc0)==0x80)
 Is this code unit (byte) a UTF-8 trail byte? More...

#define U8_LENGTH(c)
 How many code units (bytes) are used for the UTF-8 encoding of this Unicode code point? More...

#define U8_MAX_LENGTH   4
 The maximum number of UTF-8 code units (bytes) per Unicode code point (U+0000..U+10ffff). More...

#define U8_GET_UNSAFE(s, i, c)
 Get a code point from a string at a random-access offset, without changing the offset. More...

#define U8_GET(s, start, i, length, c)
 Get a code point from a string at a random-access offset, without changing the offset. More...

#define U8_NEXT_UNSAFE(s, i, c)
 Get a code point from a string at a code point boundary offset, and advance the offset to the next code point boundary. More...

#define U8_NEXT(s, i, length, c)
 Get a code point from a string at a code point boundary offset, and advance the offset to the next code point boundary. More...

#define U8_APPEND_UNSAFE(s, i, c)
 Append a code point to a string, overwriting 1 to 4 bytes. More...

#define U8_APPEND(s, i, length, c, isError)
 Append a code point to a string, overwriting 1 or 2 code units. More...

#define U8_FWD_1_UNSAFE(s, i)
 Advance the string offset from one code point boundary to the next. More...

#define U8_FWD_1(s, i, length)
 Advance the string offset from one code point boundary to the next. More...

#define U8_FWD_N_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. More...

#define U8_FWD_N(s, i, length, n)
 Advance the string offset from one code point boundary to the n-th next one, i.e., move forward by n code points. More...

#define U8_SET_CP_START_UNSAFE(s, i)
 Adjust a random-access offset to a code point boundary at the start of a code point. More...

#define U8_SET_CP_START(s, start, i)
 Adjust a random-access offset to a code point boundary at the start of a code point. More...

#define U8_PREV_UNSAFE(s, i, c)
 Move the string offset from one code point boundary to the previous one and get the code point between them. More...

#define U8_PREV(s, start, i, c)
 Move the string offset from one code point boundary to the previous one and get the code point between them. More...

#define U8_BACK_1_UNSAFE(s, i)
 Move the string offset from one code point boundary to the previous one. More...

#define U8_BACK_1(s, start, i)
 Move the string offset from one code point boundary to the previous one. More...

#define U8_BACK_N_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. More...

#define U8_BACK_N(s, start, 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. More...

#define U8_SET_CP_LIMIT_UNSAFE(s, i)
 Adjust a random-access offset to a code point boundary after a code point. More...

#define U8_SET_CP_LIMIT(s, start, i, length)
 Adjust a random-access offset to a code point boundary after a code point. More...


Functions

UChar32 utf8_nextCharSafeBody (const uint8_t *s, int32_t *pi, int32_t length, UChar32 c, UBool strict)
 Function for handling "next code point" with error-checking. More...

int32_t utf8_appendCharSafeBody (uint8_t *s, int32_t i, int32_t length, UChar32 c, UBool *pIsError)
 Function for handling "append code point" with error-checking. More...

UChar32 utf8_prevCharSafeBody (const uint8_t *s, int32_t start, int32_t *pi, UChar32 c, UBool strict)
 Function for handling "previous code point" with error-checking. More...

int32_t utf8_back1SafeBody (const uint8_t *s, int32_t start, int32_t i)
 Function for handling "skip backward one code point" with error-checking. More...


Variables

U_CFUNC U_IMPORT const uint8_t utf8_countTrailBytes [256]
 Internal array with numbers of trail bytes for any given byte used in lead byte position. More...


Detailed Description

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://oss.software.ibm.com/icu/userguide/).

Usage: 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.

Definition in file utf8.h.


Define Documentation

#define U8_APPEND s,
i,
length,
c,
isError   
 

Value:

{ \
    if((uint32_t)(c)<=0x7f) { \
        (s)[(i)++]=(uint8_t)(c); \
    } else { \
        (i)=utf8_appendCharSafeBody(s, (int32_t)(i), (int32_t)(length), c, &(isError)); \
    } \
}
Append a code point to a string, overwriting 1 or 2 code units.

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.

Parameters:
s  const uint8_t * string buffer
i  string offset, i<length
length  size of the string buffer
c  code point to append
isError  output UBool set to TRUE if an error occurs, otherwise not modified
See also:
U8_APPEND_UNSAFE
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 311 of file utf8.h.

#define U8_APPEND_UNSAFE s,
i,
 
 

Value:

{ \
    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). "Unsafe" macro, assumes a valid code point and sufficient space in the string. Otherwise, the result is undefined.

Parameters:
s  const uint8_t * string buffer
i  string offset
c  code point to append
See also:
U8_APPEND
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 275 of file utf8.h.

#define U8_BACK_1 s,
start,
 
 

Value:

{ \
    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 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.

Parameters:
s  const uint8_t * string
start  starting string offset (usually 0)
i  string offset, start<=i
See also:
U8_BACK_1_UNSAFE
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 537 of file utf8.h.

#define U8_BACK_1_UNSAFE s,
 
 

Value:

{ \
    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. "Unsafe" macro, assumes well-formed UTF-8.

Parameters:
s  const uint8_t * string
i  string offset
See also:
U8_BACK_1
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 521 of file utf8.h.

#define U8_BACK_N s,
start,
i,
 
 

Value:

{ \
    int32_t __N=(n); \
    while(__N>0 && (i)>(start)) { \
        U8_BACK_1(s, start, 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.

Parameters:
s  const uint8_t * string
start  index of the start of the string
i  string offset, i<length
n  number of code points to skip
See also:
U8_BACK_N_UNSAFE
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 578 of file utf8.h.

#define U8_BACK_N_UNSAFE s,
i,
 
 

Value:

{ \
    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. "Unsafe" macro, assumes well-formed UTF-8.

Parameters:
s  const uint8_t * string
i  string offset
n  number of code points to skip
See also:
U8_BACK_N
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 556 of file utf8.h.

#define U8_COUNT_TRAIL_BYTES leadByte       (utf8_countTrailBytes[(uint8_t)leadByte])
 

Count the trail bytes for a UTF-8 lead byte.

Internal:
For internal use only.

Definition at line 62 of file utf8.h.

#define U8_FWD_1 s,
i,
length   
 

Value:

{ \
    uint8_t __b=(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 next.

(Post-incrementing iteration.) "Safe" macro, checks for illegal sequences and for string boundaries.

Parameters:
s  const uint8_t * string
i  string offset, i<length
length  string length
See also:
U8_FWD_1_UNSAFE
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 344 of file utf8.h.

#define U8_FWD_1_UNSAFE s,
 
 

Value:

{ \
    (i)+=1+U8_COUNT_TRAIL_BYTES((s)[i]); \
}
Advance the string offset from one code point boundary to the next.

(Post-incrementing iteration.) "Unsafe" macro, assumes well-formed UTF-8.

Parameters:
s  const uint8_t * string
i  string offset
See also:
U8_FWD_1
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 329 of file utf8.h.

#define U8_FWD_N s,
i,
length,
 
 

Value:

{ \
    int32_t __N=(n); \
    while(__N>0 && (i)<(length)) { \
        U8_FWD_1(s, i, length); \
        --__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.

Parameters:
s  const uint8_t * string
i  string offset, i<length
length  string length
n  number of code points to skip
See also:
U8_FWD_N_UNSAFE
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 391 of file utf8.h.

#define U8_FWD_N_UNSAFE s,
i,
 
 

Value:

{ \
    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.) "Unsafe" macro, assumes well-formed UTF-8.

Parameters:
s  const uint8_t * string
i  string offset
n  number of code points to skip
See also:
U8_FWD_N
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 370 of file utf8.h.

#define U8_GET s,
start,
i,
length,
 
 

Value:

{ \
    int32_t __I=(int32_t)(i); \
    U8_SET_CP_START(s, start, __I); \
    U8_NEXT(s, __I, length, 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.

Parameters:
s  const uint8_t * string
start  starting string offset
i  string offset, start<=i<length
length  string length
c  output UChar32 variable, set to <0 in case of an error
See also:
U8_GET_UNSAFE
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 189 of file utf8.h.

#define U8_GET_UNSAFE s,
i,
 
 

Value:

{ \
    int32_t __I=(int32_t)(i); \
    U8_SET_CP_START_UNSAFE(s, __I); \
    U8_NEXT_UNSAFE(s, __I, 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. 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.

Parameters:
s  const uint8_t * string
i  string offset
c  output UChar32 variable
See also:
U8_GET
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 165 of file utf8.h.

#define U8_IS_LEAD      ((uint8_t)((c)-0xc0)<0x3e)
 

Is this code unit (byte) a UTF-8 lead byte?

Parameters:
c  8-bit code unit (byte)
Returns:
TRUE or FALSE
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 114 of file utf8.h.

#define U8_IS_SINGLE      (((c)&0x80)==0)
 

Does this code unit (byte) encode a code point by itself (US-ASCII 0..0x7f)?

Parameters:
c  8-bit code unit (byte)
Returns:
TRUE or FALSE
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 106 of file utf8.h.

#define U8_IS_TRAIL      (((c)&0xc0)==0x80)
 

Is this code unit (byte) a UTF-8 trail byte?

Parameters:
c  8-bit code unit (byte)
Returns:
TRUE or FALSE
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 122 of file utf8.h.

#define U8_LENGTH  
 

Value:

((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)\
                ) \
            ) \
        ) \
    )
How many code units (bytes) are used for the UTF-8 encoding of this Unicode code point?

Parameters:
c  32-bit code point
Returns:
1..4, or 0 if c is a surrogate or not a Unicode code point
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 131 of file utf8.h.

#define U8_MASK_LEAD_BYTE leadByte,
countTrailBytes       ((leadByte)&=(1<<(6-(countTrailBytes)))-1)
 

Mask a UTF-8 lead byte, leave only the lower bits that form part of the code point value.

Internal:
For internal use only.

Definition at line 68 of file utf8.h.

#define U8_MAX_LENGTH   4
 

The maximum number of UTF-8 code units (bytes) per Unicode code point (U+0000..U+10ffff).

Returns:
4
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 147 of file utf8.h.

#define U8_NEXT s,
i,
length,
 
 

Value:

{ \
    (c)=(s)[(i)++]; \
    if(((uint8_t)(c))>=0x80) { \
        if(U8_IS_LEAD(c)) { \
            (c)=utf8_nextCharSafeBody((const uint8_t *)s, &(i), (int32_t)(length), c, -1); \
        } else { \
            (c)=U_SENTINEL; \
        } \
    } \
}
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.

Parameters:
s  const uint8_t * string
i  string offset, i<length
length  string length
c  output UChar32 variable, set to <0 in case of an error
See also:
U8_NEXT_UNSAFE
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 251 of file utf8.h.

#define U8_NEXT_UNSAFE s,
i,
 
 

Value:

{ \
    (c)=(s)[(i)++]; \
    if((uint8_t)((c)-0xc0)<0x35) { \
        uint8_t __count=U8_COUNT_TRAIL_BYTES(c); \
        U8_MASK_LEAD_BYTE(c, __count); \
        switch(__count) { \
          \
        case 3: \
            (c)=((c)<<6)|((s)[(i)++]&0x3f); \
        case 2: \
            (c)=((c)<<6)|((s)[(i)++]&0x3f); \
        case 1: \
            (c)=((c)<<6)|((s)[(i)++]&0x3f); \
          \
            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.) "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.

Parameters:
s  const uint8_t * string
i  string offset
c  output UChar32 variable
See also:
U8_NEXT
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 214 of file utf8.h.

#define U8_PREV s,
start,
i,
 
 

Value:

{ \
    (c)=(s)[--(i)]; \
    if((c)>=0x80) { \
        if((c)<=0xbf) { \
            (c)=utf8_prevCharSafeBody(s, start, &(i), c, -1); \
        } else { \
            (c)=U_SENTINEL; \
        } \
    } \
}
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.

Parameters:
s  const uint8_t * string
start  starting string offset (usually 0)
i  string offset, start<=i
c  output UChar32 variable, set to <0 in case of an error
See also:
U8_PREV_UNSAFE
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 499 of file utf8.h.

#define U8_PREV_UNSAFE s,
i,
 
 

Value:

{ \
    (c)=(s)[--(i)]; \
    if(U8_IS_TRAIL(c)) { \
        uint8_t __b, __count=1, __shift=6; \
\
          \
        (c)&=0x3f; \
        for(;;) { \
            __b=(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.) "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.

Parameters:
s  const uint8_t * string
i  string offset
c  output UChar32 variable
See also:
U8_PREV
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 457 of file utf8.h.

#define U8_SET_CP_LIMIT s,
start,
i,
length   
 

Value:

{ \
    if((start)<(i) && (i)<(length)) { \
        U8_BACK_1(s, start, i); \
        U8_FWD_1(s, i, length); \
    } \
}
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.

Parameters:
s  const uint8_t * string
start  starting string offset (usually 0)
i  string offset, start<=i<=length
length  string length
See also:
U8_SET_CP_LIMIT_UNSAFE
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 619 of file utf8.h.

#define U8_SET_CP_LIMIT_UNSAFE s,
 
 

Value:

{ \
    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. "Unsafe" macro, assumes well-formed UTF-8.

Parameters:
s  const uint8_t * string
i  string offset
See also:
U8_SET_CP_LIMIT
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 599 of file utf8.h.

#define U8_SET_CP_START s,
start,
 
 

Value:

{ \
    if(U8_IS_TRAIL((s)[(i)])) { \
        (i)=utf8_back1SafeBody(s, start, (int32_t)(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.

Parameters:
s  const uint8_t * string
start  starting string offset (usually 0)
i  string offset, start<=i
See also:
U8_SET_CP_START_UNSAFE
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 430 of file utf8.h.

#define U8_SET_CP_START_UNSAFE s,
 
 

Value:

{ \
    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. "Unsafe" macro, assumes well-formed UTF-8.

Parameters:
s  const uint8_t * string
i  string offset
See also:
U8_SET_CP_START
Draft:
This API has been introduced in ICU 2.4. It is still in draft state and may be modified in a future release.

Definition at line 412 of file utf8.h.


Function Documentation

int32_t utf8_appendCharSafeBody uint8_t *    s,
int32_t    i,
int32_t    length,
UChar32    c,
UBool   pIsError
 

Function for handling "append code point" with error-checking.

Internal:
For internal use only.

int32_t utf8_back1SafeBody const uint8_t *    s,
int32_t    start,
int32_t    i
 

Function for handling "skip backward one code point" with error-checking.

Internal:
For internal use only.

UChar32 utf8_nextCharSafeBody const uint8_t *    s,
int32_t *    pi,
int32_t    length,
UChar32    c,
UBool    strict
 

Function for handling "next code point" with error-checking.

Internal:
For internal use only.

UChar32 utf8_prevCharSafeBody const uint8_t *    s,
int32_t    start,
int32_t *    pi,
UChar32    c,
UBool    strict
 

Function for handling "previous code point" with error-checking.

Internal:
For internal use only.


Variable Documentation

utf8_countTrailBytes
 

Internal array with numbers of trail bytes for any given byte used in lead byte position.

Internal:
For internal use only.


Generated on Mon Nov 24 14:36:11 2003 for ICU 2.8 by doxygen1.2.11.1 written by Dimitri van Heesch, © 1997-2001