606 lines
18 KiB
C
606 lines
18 KiB
C
/*
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*******************************************************************************
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*
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* Copyright (C) 1999-2004, International Business Machines
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* Corporation and others. All Rights Reserved.
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*
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*******************************************************************************
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* file name: utf16.h
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* encoding: US-ASCII
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* tab size: 8 (not used)
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* indentation:4
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*
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* created on: 1999sep09
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* created by: Markus W. Scherer
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*/
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/**
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* \file
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* \brief C API: 16-bit Unicode handling macros
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*
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* This file defines macros to deal with 16-bit Unicode (UTF-16) code units and strings.
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* utf16.h is included by utf.h after unicode/umachine.h
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* and some common definitions.
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*
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* For more information see utf.h and the ICU User Guide Strings chapter
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* (http://oss.software.ibm.com/icu/userguide/).
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*
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* <em>Usage:</em>
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* ICU coding guidelines for if() statements should be followed when using these macros.
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* Compound statements (curly braces {}) must be used for if-else-while...
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* bodies and all macro statements should be terminated with semicolon.
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*/
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#ifndef __UTF16_H__
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#define __UTF16_H__
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/* utf.h must be included first. */
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#ifndef __UTF_H__
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# include "unicode/utf.h"
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#endif
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/* single-code point definitions -------------------------------------------- */
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/**
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* Does this code unit alone encode a code point (BMP, not a surrogate)?
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* @param c 16-bit code unit
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* @return TRUE or FALSE
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* @stable ICU 2.4
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*/
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#define U16_IS_SINGLE(c) !U_IS_SURROGATE(c)
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/**
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* Is this code unit a lead surrogate (U+d800..U+dbff)?
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* @param c 16-bit code unit
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* @return TRUE or FALSE
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* @stable ICU 2.4
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*/
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#define U16_IS_LEAD(c) (((c)&0xfffffc00)==0xd800)
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/**
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* Is this code unit a trail surrogate (U+dc00..U+dfff)?
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* @param c 16-bit code unit
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* @return TRUE or FALSE
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* @stable ICU 2.4
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*/
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#define U16_IS_TRAIL(c) (((c)&0xfffffc00)==0xdc00)
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/**
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* Is this code unit a surrogate (U+d800..U+dfff)?
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* @param c 16-bit code unit
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* @return TRUE or FALSE
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* @stable ICU 2.4
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*/
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#define U16_IS_SURROGATE(c) U_IS_SURROGATE(c)
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/**
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* Assuming c is a surrogate code point (U16_IS_SURROGATE(c)),
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* is it a lead surrogate?
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* @param c 16-bit code unit
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* @return TRUE or FALSE
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* @stable ICU 2.4
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*/
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#define U16_IS_SURROGATE_LEAD(c) (((c)&0x400)==0)
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/**
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* Helper constant for U16_GET_SUPPLEMENTARY.
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* @internal
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*/
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#define U16_SURROGATE_OFFSET ((0xd800<<10UL)+0xdc00-0x10000)
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/**
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* Get a supplementary code point value (U+10000..U+10ffff)
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* from its lead and trail surrogates.
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* The result is undefined if the input values are not
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* lead and trail surrogates.
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*
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* @param lead lead surrogate (U+d800..U+dbff)
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* @param trail trail surrogate (U+dc00..U+dfff)
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* @return supplementary code point (U+10000..U+10ffff)
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* @stable ICU 2.4
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*/
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#define U16_GET_SUPPLEMENTARY(lead, trail) \
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(((UChar32)(lead)<<10UL)+(UChar32)(trail)-U16_SURROGATE_OFFSET)
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/**
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* Get the lead surrogate (0xd800..0xdbff) for a
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* supplementary code point (0x10000..0x10ffff).
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* @param supplementary 32-bit code point (U+10000..U+10ffff)
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* @return lead surrogate (U+d800..U+dbff) for supplementary
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* @stable ICU 2.4
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*/
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#define U16_LEAD(supplementary) (UChar)(((supplementary)>>10)+0xd7c0)
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/**
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* Get the trail surrogate (0xdc00..0xdfff) for a
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* supplementary code point (0x10000..0x10ffff).
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* @param supplementary 32-bit code point (U+10000..U+10ffff)
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* @return trail surrogate (U+dc00..U+dfff) for supplementary
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* @stable ICU 2.4
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*/
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#define U16_TRAIL(supplementary) (UChar)(((supplementary)&0x3ff)|0xdc00)
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/**
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* How many 16-bit code units are used to encode this Unicode code point? (1 or 2)
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* The result is not defined if c is not a Unicode code point (U+0000..U+10ffff).
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* @param c 32-bit code point
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* @return 1 or 2
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* @stable ICU 2.4
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*/
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#define U16_LENGTH(c) ((uint32_t)(c)<=0xffff ? 1 : 2)
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/**
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* The maximum number of 16-bit code units per Unicode code point (U+0000..U+10ffff).
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* @return 2
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* @stable ICU 2.4
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*/
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#define U16_MAX_LENGTH 2
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/**
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* Get a code point from a string at a random-access offset,
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* without changing the offset.
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* "Unsafe" macro, assumes well-formed UTF-16.
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*
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* The offset may point to either the lead or trail surrogate unit
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* for a supplementary code point, in which case the macro will read
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* the adjacent matching surrogate as well.
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* The result is undefined if the offset points to a single, unpaired surrogate.
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* Iteration through a string is more efficient with U16_NEXT_UNSAFE or U16_NEXT.
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*
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* @param s const UChar * string
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* @param i string offset
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* @param c output UChar32 variable
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* @see U16_GET
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* @stable ICU 2.4
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*/
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#define U16_GET_UNSAFE(s, i, c) { \
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(c)=(s)[i]; \
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if(U16_IS_SURROGATE(c)) { \
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if(U16_IS_SURROGATE_LEAD(c)) { \
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(c)=U16_GET_SUPPLEMENTARY((c), (s)[(i)+1]); \
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} else { \
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(c)=U16_GET_SUPPLEMENTARY((s)[(i)-1], (c)); \
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} \
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} \
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}
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/**
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* Get a code point from a string at a random-access offset,
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* without changing the offset.
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* "Safe" macro, handles unpaired surrogates and checks for string boundaries.
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*
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* The offset may point to either the lead or trail surrogate unit
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* for a supplementary code point, in which case the macro will read
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* the adjacent matching surrogate as well.
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* If the offset points to a single, unpaired surrogate, then that itself
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* will be returned as the code point.
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* Iteration through a string is more efficient with U16_NEXT_UNSAFE or U16_NEXT.
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*
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* @param s const UChar * string
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* @param start starting string offset (usually 0)
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* @param i string offset, start<=i<length
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* @param length string length
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* @param c output UChar32 variable
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* @see U16_GET_UNSAFE
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* @stable ICU 2.4
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*/
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#define U16_GET(s, start, i, length, c) { \
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(c)=(s)[i]; \
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if(U16_IS_SURROGATE(c)) { \
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uint16_t __c2; \
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if(U16_IS_SURROGATE_LEAD(c)) { \
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if((i)+1<(length) && U16_IS_TRAIL(__c2=(s)[(i)+1])) { \
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(c)=U16_GET_SUPPLEMENTARY((c), __c2); \
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} \
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} else { \
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if((i)-1>=(start) && U16_IS_LEAD(__c2=(s)[(i)-1])) { \
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(c)=U16_GET_SUPPLEMENTARY(__c2, (c)); \
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} \
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} \
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} \
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}
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/* definitions with forward iteration --------------------------------------- */
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/**
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* Get a code point from a string at a code point boundary offset,
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* and advance the offset to the next code point boundary.
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* (Post-incrementing forward iteration.)
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* "Unsafe" macro, assumes well-formed UTF-16.
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*
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* The offset may point to the lead surrogate unit
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* for a supplementary code point, in which case the macro will read
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* the following trail surrogate as well.
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* If the offset points to a trail surrogate, then that itself
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* will be returned as the code point.
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* The result is undefined if the offset points to a single, unpaired lead surrogate.
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*
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* @param s const UChar * string
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* @param i string offset
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* @param c output UChar32 variable
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* @see U16_NEXT
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* @stable ICU 2.4
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*/
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#define U16_NEXT_UNSAFE(s, i, c) { \
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(c)=(s)[(i)++]; \
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if(U16_IS_LEAD(c)) { \
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(c)=U16_GET_SUPPLEMENTARY((c), (s)[(i)++]); \
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} \
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}
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/**
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* Get a code point from a string at a code point boundary offset,
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* and advance the offset to the next code point boundary.
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* (Post-incrementing forward iteration.)
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* "Safe" macro, handles unpaired surrogates and checks for string boundaries.
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*
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* The offset may point to the lead surrogate unit
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* for a supplementary code point, in which case the macro will read
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* the following trail surrogate as well.
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* If the offset points to a trail surrogate or
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* to a single, unpaired lead surrogate, then that itself
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* will be returned as the code point.
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*
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* @param s const UChar * string
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* @param i string offset, i<length
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* @param length string length
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* @param c output UChar32 variable
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* @see U16_NEXT_UNSAFE
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* @stable ICU 2.4
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*/
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#define U16_NEXT(s, i, length, c) { \
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(c)=(s)[(i)++]; \
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if(U16_IS_LEAD(c)) { \
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uint16_t __c2; \
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if((i)<(length) && U16_IS_TRAIL(__c2=(s)[(i)])) { \
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++(i); \
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(c)=U16_GET_SUPPLEMENTARY((c), __c2); \
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} \
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} \
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}
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/**
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* Append a code point to a string, overwriting 1 or 2 code units.
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* The offset points to the current end of the string contents
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* and is advanced (post-increment).
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* "Unsafe" macro, assumes a valid code point and sufficient space in the string.
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* Otherwise, the result is undefined.
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*
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* @param s const UChar * string buffer
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* @param i string offset
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* @param c code point to append
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* @see U16_APPEND
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* @stable ICU 2.4
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*/
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#define U16_APPEND_UNSAFE(s, i, c) { \
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if((uint32_t)(c)<=0xffff) { \
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(s)[(i)++]=(uint16_t)(c); \
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} else { \
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(s)[(i)++]=(uint16_t)(((c)>>10)+0xd7c0); \
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(s)[(i)++]=(uint16_t)(((c)&0x3ff)|0xdc00); \
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} \
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}
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/**
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* Append a code point to a string, overwriting 1 or 2 code units.
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* The offset points to the current end of the string contents
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* and is advanced (post-increment).
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* "Safe" macro, checks for a valid code point.
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* If a surrogate pair is written, checks for sufficient space in the string.
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* If the code point is not valid or a trail surrogate does not fit,
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* then isError is set to TRUE.
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*
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* @param s const UChar * string buffer
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* @param i string offset, i<length
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* @param capacity size of the string buffer
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* @param c code point to append
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* @param isError output UBool set to TRUE if an error occurs, otherwise not modified
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* @see U16_APPEND_UNSAFE
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* @stable ICU 2.4
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*/
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#define U16_APPEND(s, i, capacity, c, isError) { \
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if((uint32_t)(c)<=0xffff) { \
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(s)[(i)++]=(uint16_t)(c); \
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} else if((uint32_t)(c)<=0x10ffff && (i)+1<(capacity)) { \
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(s)[(i)++]=(uint16_t)(((c)>>10)+0xd7c0); \
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(s)[(i)++]=(uint16_t)(((c)&0x3ff)|0xdc00); \
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} else /* c>0x10ffff or not enough space */ { \
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(isError)=TRUE; \
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} \
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}
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/**
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* Advance the string offset from one code point boundary to the next.
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* (Post-incrementing iteration.)
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* "Unsafe" macro, assumes well-formed UTF-16.
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*
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* @param s const UChar * string
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* @param i string offset
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* @see U16_FWD_1
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* @stable ICU 2.4
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*/
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#define U16_FWD_1_UNSAFE(s, i) { \
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if(U16_IS_LEAD((s)[(i)++])) { \
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++(i); \
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} \
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}
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/**
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* Advance the string offset from one code point boundary to the next.
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* (Post-incrementing iteration.)
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* "Safe" macro, handles unpaired surrogates and checks for string boundaries.
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*
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* @param s const UChar * string
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* @param i string offset, i<length
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* @param length string length
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* @see U16_FWD_1_UNSAFE
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* @stable ICU 2.4
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*/
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#define U16_FWD_1(s, i, length) { \
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if(U16_IS_LEAD((s)[(i)++]) && (i)<(length) && U16_IS_TRAIL((s)[i])) { \
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++(i); \
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} \
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}
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/**
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* Advance the string offset from one code point boundary to the n-th next one,
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* i.e., move forward by n code points.
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* (Post-incrementing iteration.)
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* "Unsafe" macro, assumes well-formed UTF-16.
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*
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* @param s const UChar * string
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* @param i string offset
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* @param n number of code points to skip
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* @see U16_FWD_N
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* @stable ICU 2.4
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*/
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#define U16_FWD_N_UNSAFE(s, i, n) { \
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int32_t __N=(n); \
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while(__N>0) { \
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U16_FWD_1_UNSAFE(s, i); \
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--__N; \
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} \
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}
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/**
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* Advance the string offset from one code point boundary to the n-th next one,
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* i.e., move forward by n code points.
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* (Post-incrementing iteration.)
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* "Safe" macro, handles unpaired surrogates and checks for string boundaries.
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*
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* @param s const UChar * string
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* @param i string offset, i<length
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* @param length string length
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* @param n number of code points to skip
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* @see U16_FWD_N_UNSAFE
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* @stable ICU 2.4
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*/
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#define U16_FWD_N(s, i, length, n) { \
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int32_t __N=(n); \
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while(__N>0 && (i)<(length)) { \
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U16_FWD_1(s, i, length); \
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--__N; \
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} \
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}
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/**
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* Adjust a random-access offset to a code point boundary
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* at the start of a code point.
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* If the offset points to the trail surrogate of a surrogate pair,
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* then the offset is decremented.
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* Otherwise, it is not modified.
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* "Unsafe" macro, assumes well-formed UTF-16.
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*
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* @param s const UChar * string
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* @param i string offset
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* @see U16_SET_CP_START
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* @stable ICU 2.4
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*/
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#define U16_SET_CP_START_UNSAFE(s, i) { \
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if(U16_IS_TRAIL((s)[i])) { \
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--(i); \
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} \
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}
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/**
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* Adjust a random-access offset to a code point boundary
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* at the start of a code point.
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* If the offset points to the trail surrogate of a surrogate pair,
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* then the offset is decremented.
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* Otherwise, it is not modified.
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* "Safe" macro, handles unpaired surrogates and checks for string boundaries.
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*
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* @param s const UChar * string
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* @param start starting string offset (usually 0)
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* @param i string offset, start<=i
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* @see U16_SET_CP_START_UNSAFE
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* @stable ICU 2.4
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*/
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#define U16_SET_CP_START(s, start, i) { \
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if(U16_IS_TRAIL((s)[i]) && (i)>(start) && U16_IS_LEAD((s)[(i)-1])) { \
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--(i); \
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} \
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}
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/* definitions with backward iteration -------------------------------------- */
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/**
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* Move the string offset from one code point boundary to the previous one
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* and get the code point between them.
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* (Pre-decrementing backward iteration.)
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* "Unsafe" macro, assumes well-formed UTF-16.
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*
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* The input offset may be the same as the string length.
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* If the offset is behind a trail surrogate unit
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* for a supplementary code point, then the macro will read
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* the preceding lead surrogate as well.
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* If the offset is behind a lead surrogate, then that itself
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* will be returned as the code point.
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* The result is undefined if the offset is behind a single, unpaired trail surrogate.
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*
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* @param s const UChar * string
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* @param i string offset
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* @param c output UChar32 variable
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* @see U16_PREV
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* @stable ICU 2.4
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*/
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#define U16_PREV_UNSAFE(s, i, c) { \
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(c)=(s)[--(i)]; \
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if(U16_IS_TRAIL(c)) { \
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(c)=U16_GET_SUPPLEMENTARY((s)[--(i)], (c)); \
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} \
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}
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/**
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* Move the string offset from one code point boundary to the previous one
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* and get the code point between them.
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* (Pre-decrementing backward iteration.)
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* "Safe" macro, handles unpaired surrogates and checks for string boundaries.
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*
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* The input offset may be the same as the string length.
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* If the offset is behind a trail surrogate unit
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* for a supplementary code point, then the macro will read
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* the preceding lead surrogate as well.
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* If the offset is behind a lead surrogate or behind a single, unpaired
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* trail surrogate, then that itself
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* will be returned as the code point.
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*
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* @param s const UChar * string
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* @param start starting string offset (usually 0)
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* @param i string offset, start<=i
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* @param c output UChar32 variable
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* @see U16_PREV_UNSAFE
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* @stable ICU 2.4
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*/
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#define U16_PREV(s, start, i, c) { \
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(c)=(s)[--(i)]; \
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if(U16_IS_TRAIL(c)) { \
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uint16_t __c2; \
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if((i)>(start) && U16_IS_LEAD(__c2=(s)[(i)-1])) { \
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--(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, 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, i<length
|
|
* @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
|