| /* |
| ******************************************************************************* |
| * |
| * Copyright (C) 1999-2008, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| * |
| ******************************************************************************* |
| * file name: utf16.h |
| * encoding: US-ASCII |
| * tab size: 8 (not used) |
| * indentation:4 |
| * |
| * created on: 1999sep09 |
| * created by: Markus W. Scherer |
| */ |
| |
| /** |
| * \file |
| * \brief C API: 16-bit Unicode handling macros |
| * |
| * This file defines macros to deal with 16-bit Unicode (UTF-16) code units and strings. |
| * utf16.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 __UTF16_H__ |
| #define __UTF16_H__ |
| |
| /* utf.h must be included first. */ |
| #ifndef __UTF_H__ |
| # include "unicode/utf.h" |
| #endif |
| |
| /* single-code point definitions -------------------------------------------- */ |
| |
| /** |
| * Does this code unit alone encode a code point (BMP, not a surrogate)? |
| * @param c 16-bit code unit |
| * @return TRUE or FALSE |
| * @stable ICU 2.4 |
| */ |
| #define U16_IS_SINGLE(c) !U_IS_SURROGATE(c) |
| |
| /** |
| * Is this code unit a lead surrogate (U+d800..U+dbff)? |
| * @param c 16-bit code unit |
| * @return TRUE or FALSE |
| * @stable ICU 2.4 |
| */ |
| #define U16_IS_LEAD(c) (((c)&0xfffffc00)==0xd800) |
| |
| /** |
| * Is this code unit a trail surrogate (U+dc00..U+dfff)? |
| * @param c 16-bit code unit |
| * @return TRUE or FALSE |
| * @stable ICU 2.4 |
| */ |
| #define U16_IS_TRAIL(c) (((c)&0xfffffc00)==0xdc00) |
| |
| /** |
| * Is this code unit a surrogate (U+d800..U+dfff)? |
| * @param c 16-bit code unit |
| * @return TRUE or FALSE |
| * @stable ICU 2.4 |
| */ |
| #define U16_IS_SURROGATE(c) U_IS_SURROGATE(c) |
| |
| /** |
| * Assuming c is a surrogate code point (U16_IS_SURROGATE(c)), |
| * is it a lead surrogate? |
| * @param c 16-bit code unit |
| * @return TRUE or FALSE |
| * @stable ICU 2.4 |
| */ |
| #define U16_IS_SURROGATE_LEAD(c) (((c)&0x400)==0) |
| |
| /** |
| * Assuming c is a surrogate code point (U16_IS_SURROGATE(c)), |
| * is it a trail surrogate? |
| * @param c 16-bit code unit |
| * @return TRUE or FALSE |
| * @draft ICU 4.2 |
| */ |
| #define U16_IS_SURROGATE_TRAIL(c) (((c)&0x400)!=0) |
| |
| /** |
| * Helper constant for U16_GET_SUPPLEMENTARY. |
| * @internal |
| */ |
| #define U16_SURROGATE_OFFSET ((0xd800<<10UL)+0xdc00-0x10000) |
| |
| /** |
| * Get a supplementary code point value (U+10000..U+10ffff) |
| * from its lead and trail surrogates. |
| * The result is undefined if the input values are not |
| * lead and trail surrogates. |
| * |
| * @param lead lead surrogate (U+d800..U+dbff) |
| * @param trail trail surrogate (U+dc00..U+dfff) |
| * @return supplementary code point (U+10000..U+10ffff) |
| * @stable ICU 2.4 |
| */ |
| #define U16_GET_SUPPLEMENTARY(lead, trail) \ |
| (((UChar32)(lead)<<10UL)+(UChar32)(trail)-U16_SURROGATE_OFFSET) |
| |
| |
| /** |
| * Get the lead surrogate (0xd800..0xdbff) for a |
| * supplementary code point (0x10000..0x10ffff). |
| * @param supplementary 32-bit code point (U+10000..U+10ffff) |
| * @return lead surrogate (U+d800..U+dbff) for supplementary |
| * @stable ICU 2.4 |
| */ |
| #define U16_LEAD(supplementary) (UChar)(((supplementary)>>10)+0xd7c0) |
| |
| /** |
| * Get the trail surrogate (0xdc00..0xdfff) for a |
| * supplementary code point (0x10000..0x10ffff). |
| * @param supplementary 32-bit code point (U+10000..U+10ffff) |
| * @return trail surrogate (U+dc00..U+dfff) for supplementary |
| * @stable ICU 2.4 |
| */ |
| #define U16_TRAIL(supplementary) (UChar)(((supplementary)&0x3ff)|0xdc00) |
| |
| /** |
| * How many 16-bit code units are used to encode this Unicode code point? (1 or 2) |
| * The result is not defined if c is not a Unicode code point (U+0000..U+10ffff). |
| * @param c 32-bit code point |
| * @return 1 or 2 |
| * @stable ICU 2.4 |
| */ |
| #define U16_LENGTH(c) ((uint32_t)(c)<=0xffff ? 1 : 2) |
| |
| /** |
| * The maximum number of 16-bit code units per Unicode code point (U+0000..U+10ffff). |
| * @return 2 |
| * @stable ICU 2.4 |
| */ |
| #define U16_MAX_LENGTH 2 |
| |
| /** |
| * Get a code point from a string at a random-access offset, |
| * without changing the offset. |
| * "Unsafe" macro, assumes well-formed UTF-16. |
| * |
| * The offset may point to either the lead or trail surrogate unit |
| * for a supplementary code point, in which case the macro will read |
| * the adjacent matching surrogate as well. |
| * The result is undefined if the offset points to a single, unpaired surrogate. |
| * Iteration through a string is more efficient with U16_NEXT_UNSAFE or U16_NEXT. |
| * |
| * @param s const UChar * string |
| * @param i string offset |
| * @param c output UChar32 variable |
| * @see U16_GET |
| * @stable ICU 2.4 |
| */ |
| #define U16_GET_UNSAFE(s, i, c) { \ |
| (c)=(s)[i]; \ |
| if(U16_IS_SURROGATE(c)) { \ |
| if(U16_IS_SURROGATE_LEAD(c)) { \ |
| (c)=U16_GET_SUPPLEMENTARY((c), (s)[(i)+1]); \ |
| } else { \ |
| (c)=U16_GET_SUPPLEMENTARY((s)[(i)-1], (c)); \ |
| } \ |
| } \ |
| } |
| |
| /** |
| * Get a code point from a string at a random-access offset, |
| * without changing the offset. |
| * "Safe" macro, handles unpaired surrogates and checks for string boundaries. |
| * |
| * The offset may point to either the lead or trail surrogate unit |
| * for a supplementary code point, in which case the macro will read |
| * the adjacent matching surrogate as well. |
| * If the offset points to a single, unpaired surrogate, then that itself |
| * will be returned as the code point. |
| * Iteration through a string is more efficient with U16_NEXT_UNSAFE or U16_NEXT. |
| * |
| * @param s const UChar * string |
| * @param start starting string offset (usually 0) |
| * @param i string offset, must be start<=i<length |
| * @param length string length |
| * @param c output UChar32 variable |
| * @see U16_GET_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U16_GET(s, start, i, length, c) { \ |
| (c)=(s)[i]; \ |
| if(U16_IS_SURROGATE(c)) { \ |
| uint16_t __c2; \ |
| if(U16_IS_SURROGATE_LEAD(c)) { \ |
| if((i)+1<(length) && U16_IS_TRAIL(__c2=(s)[(i)+1])) { \ |
| (c)=U16_GET_SUPPLEMENTARY((c), __c2); \ |
| } \ |
| } else { \ |
| if((i)-1>=(start) && U16_IS_LEAD(__c2=(s)[(i)-1])) { \ |
| (c)=U16_GET_SUPPLEMENTARY(__c2, (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-16. |
| * |
| * The offset may point to the lead surrogate unit |
| * for a supplementary code point, in which case the macro will read |
| * the following trail surrogate as well. |
| * If the offset points to a trail surrogate, then that itself |
| * will be returned as the code point. |
| * The result is undefined if the offset points to a single, unpaired lead surrogate. |
| * |
| * @param s const UChar * string |
| * @param i string offset |
| * @param c output UChar32 variable |
| * @see U16_NEXT |
| * @stable ICU 2.4 |
| */ |
| #define U16_NEXT_UNSAFE(s, i, c) { \ |
| (c)=(s)[(i)++]; \ |
| if(U16_IS_LEAD(c)) { \ |
| (c)=U16_GET_SUPPLEMENTARY((c), (s)[(i)++]); \ |
| } \ |
| } |
| |
| /** |
| * 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, handles unpaired surrogates and checks for string boundaries. |
| * |
| * The offset may point to the lead surrogate unit |
| * for a supplementary code point, in which case the macro will read |
| * the following trail surrogate as well. |
| * If the offset points to a trail surrogate or |
| * to a single, unpaired lead surrogate, then that itself |
| * will be returned as the code point. |
| * |
| * @param s const UChar * string |
| * @param i string offset, must be i<length |
| * @param length string length |
| * @param c output UChar32 variable |
| * @see U16_NEXT_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U16_NEXT(s, i, length, c) { \ |
| (c)=(s)[(i)++]; \ |
| if(U16_IS_LEAD(c)) { \ |
| uint16_t __c2; \ |
| if((i)<(length) && U16_IS_TRAIL(__c2=(s)[(i)])) { \ |
| ++(i); \ |
| (c)=U16_GET_SUPPLEMENTARY((c), __c2); \ |
| } \ |
| } \ |
| } |
| |
| /** |
| * 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). |
| * "Unsafe" macro, assumes a valid code point and sufficient space in the string. |
| * Otherwise, the result is undefined. |
| * |
| * @param s const UChar * string buffer |
| * @param i string offset |
| * @param c code point to append |
| * @see U16_APPEND |
| * @stable ICU 2.4 |
| */ |
| #define U16_APPEND_UNSAFE(s, i, c) { \ |
| if((uint32_t)(c)<=0xffff) { \ |
| (s)[(i)++]=(uint16_t)(c); \ |
| } else { \ |
| (s)[(i)++]=(uint16_t)(((c)>>10)+0xd7c0); \ |
| (s)[(i)++]=(uint16_t)(((c)&0x3ff)|0xdc00); \ |
| } \ |
| } |
| |
| /** |
| * 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 surrogate pair is written, checks for sufficient space in the string. |
| * If the code point is not valid or a trail surrogate does not fit, |
| * then isError is set to TRUE. |
| * |
| * @param s const UChar * 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 U16_APPEND_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U16_APPEND(s, i, capacity, c, isError) { \ |
| if((uint32_t)(c)<=0xffff) { \ |
| (s)[(i)++]=(uint16_t)(c); \ |
| } else if((uint32_t)(c)<=0x10ffff && (i)+1<(capacity)) { \ |
| (s)[(i)++]=(uint16_t)(((c)>>10)+0xd7c0); \ |
| (s)[(i)++]=(uint16_t)(((c)&0x3ff)|0xdc00); \ |
| } else /* c>0x10ffff or not enough space */ { \ |
| (isError)=TRUE; \ |
| } \ |
| } |
| |
| /** |
| * Advance the string offset from one code point boundary to the next. |
| * (Post-incrementing iteration.) |
| * "Unsafe" macro, assumes well-formed UTF-16. |
| * |
| * @param s const UChar * string |
| * @param i string offset |
| * @see U16_FWD_1 |
| * @stable ICU 2.4 |
| */ |
| #define U16_FWD_1_UNSAFE(s, i) { \ |
| if(U16_IS_LEAD((s)[(i)++])) { \ |
| ++(i); \ |
| } \ |
| } |
| |
| /** |
| * Advance the string offset from one code point boundary to the next. |
| * (Post-incrementing iteration.) |
| * "Safe" macro, handles unpaired surrogates and checks for string boundaries. |
| * |
| * @param s const UChar * string |
| * @param i string offset, must be i<length |
| * @param length string length |
| * @see U16_FWD_1_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U16_FWD_1(s, i, length) { \ |
| if(U16_IS_LEAD((s)[(i)++]) && (i)<(length) && U16_IS_TRAIL((s)[i])) { \ |
| ++(i); \ |
| } \ |
| } |
| |
| /** |
| * 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-16. |
| * |
| * @param s const UChar * string |
| * @param i string offset |
| * @param n number of code points to skip |
| * @see U16_FWD_N |
| * @stable ICU 2.4 |
| */ |
| #define U16_FWD_N_UNSAFE(s, i, n) { \ |
| int32_t __N=(n); \ |
| while(__N>0) { \ |
| U16_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, handles unpaired surrogates and checks for string boundaries. |
| * |
| * @param s const UChar * string |
| * @param i string offset, must be i<length |
| * @param length string length |
| * @param n number of code points to skip |
| * @see U16_FWD_N_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U16_FWD_N(s, i, length, n) { \ |
| int32_t __N=(n); \ |
| while(__N>0 && (i)<(length)) { \ |
| U16_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 the trail surrogate of a surrogate pair, |
| * then the offset is decremented. |
| * Otherwise, it is not modified. |
| * "Unsafe" macro, assumes well-formed UTF-16. |
| * |
| * @param s const UChar * string |
| * @param i string offset |
| * @see U16_SET_CP_START |
| * @stable ICU 2.4 |
| */ |
| #define U16_SET_CP_START_UNSAFE(s, i) { \ |
| if(U16_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 the trail surrogate of a surrogate pair, |
| * then the offset is decremented. |
| * Otherwise, it is not modified. |
| * "Safe" macro, handles unpaired surrogates and checks for string boundaries. |
| * |
| * @param s const UChar * string |
| * @param start starting string offset (usually 0) |
| * @param i string offset, must be start<=i |
| * @see U16_SET_CP_START_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U16_SET_CP_START(s, start, i) { \ |
| if(U16_IS_TRAIL((s)[i]) && (i)>(start) && U16_IS_LEAD((s)[(i)-1])) { \ |
| --(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-16. |
| * |
| * The input offset may be the same as the string length. |
| * If the offset is behind a trail surrogate unit |
| * for a supplementary code point, then the macro will read |
| * the preceding lead surrogate as well. |
| * If the offset is behind a lead surrogate, then that itself |
| * will be returned as the code point. |
| * The result is undefined if the offset is behind a single, unpaired trail surrogate. |
| * |
| * @param s const UChar * string |
| * @param i string offset |
| * @param c output UChar32 variable |
| * @see U16_PREV |
| * @stable ICU 2.4 |
| */ |
| #define U16_PREV_UNSAFE(s, i, c) { \ |
| (c)=(s)[--(i)]; \ |
| if(U16_IS_TRAIL(c)) { \ |
| (c)=U16_GET_SUPPLEMENTARY((s)[--(i)], (c)); \ |
| } \ |
| } |
| |
| /** |
| * 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, handles unpaired surrogates and checks for string boundaries. |
| * |
| * The input offset may be the same as the string length. |
| * If the offset is behind a trail surrogate unit |
| * for a supplementary code point, then the macro will read |
| * the preceding lead surrogate as well. |
| * If the offset is behind a lead surrogate or behind a single, unpaired |
| * trail surrogate, then that itself |
| * will be returned as the code point. |
| * |
| * @param s const UChar * string |
| * @param start starting string offset (usually 0) |
| * @param i string offset, must be start<i |
| * @param c output UChar32 variable |
| * @see U16_PREV_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U16_PREV(s, start, i, c) { \ |
| (c)=(s)[--(i)]; \ |
| if(U16_IS_TRAIL(c)) { \ |
| uint16_t __c2; \ |
| if((i)>(start) && U16_IS_LEAD(__c2=(s)[(i)-1])) { \ |
| --(i); \ |
| (c)=U16_GET_SUPPLEMENTARY(__c2, (c)); \ |
| } \ |
| } \ |
| } |
| |
| /** |
| * 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-16. |
| * |
| * @param s const UChar * string |
| * @param i string offset |
| * @see U16_BACK_1 |
| * @stable ICU 2.4 |
| */ |
| #define U16_BACK_1_UNSAFE(s, i) { \ |
| if(U16_IS_TRAIL((s)[--(i)])) { \ |
| --(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, handles unpaired surrogates and checks for string boundaries. |
| * |
| * @param s const UChar * string |
| * @param start starting string offset (usually 0) |
| * @param i string offset, must be start<i |
| * @see U16_BACK_1_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U16_BACK_1(s, start, i) { \ |
| if(U16_IS_TRAIL((s)[--(i)]) && (i)>(start) && U16_IS_LEAD((s)[(i)-1])) { \ |
| --(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-16. |
| * |
| * @param s const UChar * string |
| * @param i string offset |
| * @param n number of code points to skip |
| * @see U16_BACK_N |
| * @stable ICU 2.4 |
| */ |
| #define U16_BACK_N_UNSAFE(s, i, n) { \ |
| int32_t __N=(n); \ |
| while(__N>0) { \ |
| U16_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, handles unpaired surrogates and checks for string boundaries. |
| * |
| * @param s const UChar * string |
| * @param start start of string |
| * @param i string offset, must be start<i |
| * @param n number of code points to skip |
| * @see U16_BACK_N_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U16_BACK_N(s, start, i, n) { \ |
| int32_t __N=(n); \ |
| while(__N>0 && (i)>(start)) { \ |
| U16_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 the lead surrogate of a surrogate pair, |
| * then the offset is incremented. |
| * Otherwise, it is not modified. |
| * The input offset may be the same as the string length. |
| * "Unsafe" macro, assumes well-formed UTF-16. |
| * |
| * @param s const UChar * string |
| * @param i string offset |
| * @see U16_SET_CP_LIMIT |
| * @stable ICU 2.4 |
| */ |
| #define U16_SET_CP_LIMIT_UNSAFE(s, i) { \ |
| if(U16_IS_LEAD((s)[(i)-1])) { \ |
| ++(i); \ |
| } \ |
| } |
| |
| /** |
| * Adjust a random-access offset to a code point boundary after a code point. |
| * If the offset is behind the lead surrogate of a surrogate pair, |
| * then the offset is incremented. |
| * Otherwise, it is not modified. |
| * The input offset may be the same as the string length. |
| * "Safe" macro, handles unpaired surrogates and checks for string boundaries. |
| * |
| * @param s const UChar * string |
| * @param start starting string offset (usually 0) |
| * @param i string offset, start<=i<=length |
| * @param length string length |
| * @see U16_SET_CP_LIMIT_UNSAFE |
| * @stable ICU 2.4 |
| */ |
| #define U16_SET_CP_LIMIT(s, start, i, length) { \ |
| if((start)<(i) && (i)<(length) && U16_IS_LEAD((s)[(i)-1]) && U16_IS_TRAIL((s)[i])) { \ |
| ++(i); \ |
| } \ |
| } |
| |
| #endif |