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/*
*******************************************************************************
*
* Copyright (C) 1999-2004, 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://oss.software.ibm.com/icu/userguide/).
*
* <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.
* @internal
*/
#ifdef U_UTF8_IMPL
U_INTERNAL const uint8_t
#elif defined(U_STATIC_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.
* @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.
* @internal
*/
#define U8_MASK_LEAD_BYTE(leadByte, countTrailBytes) ((leadByte)&=(1<<(6-(countTrailBytes)))-1)
/**
* Function for handling "next code point" with error-checking.
* @internal
*/
U_INTERNAL 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.
* @internal
*/
U_INTERNAL 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.
* @internal
*/
U_INTERNAL 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.
* @internal
*/
U_INTERNAL 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, 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)=(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, 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)=(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; \
} \
} \
}
/**
* 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 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.
*
* @param s const uint8_t * string buffer
* @param i string offset, i<length
* @param length 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, length, c, isError) { \
if((uint32_t)(c)<=0x7f) { \
(s)[(i)++]=(uint8_t)(c); \
} else { \
(i)=utf8_appendCharSafeBody(s, (int32_t)(i), (int32_t)(length), 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, 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=(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, 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, 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)=(s)[--(i)]; \
if(U8_IS_TRAIL(c)) { \
uint8_t __b, __count=1, __shift=6; \
\
/* c is a trail byte */ \
(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.)
* "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, 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)=(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.
* (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, 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, i<length
* @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, 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
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