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 // © 2016 and later: Unicode, Inc. and others.
 // License & terms of use: http://www.unicode.org/copyright.html
 /*
 *******************************************************************************
 *
 *   Copyright (C) 2004-2012, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 *******************************************************************************
 *   file name:  utext.h
 *   encoding:   UTF-8
 *   tab size:   8 (not used)
 *   indentation:4
 *
 *   created on: 2004oct06
 *   created by: Markus W. Scherer
 */
 
 #ifndef __UTEXT_H__
 #define __UTEXT_H__
 
 /**
  * \file
  * \brief C API: Abstract Unicode Text API
  *
  * The Text Access API provides a means to allow text that is stored in alternative
  * formats to work with ICU services.  ICU normally operates on text that is
  * stored in UTF-16 format, in (UChar *) arrays for the C APIs or as type
  * UnicodeString for C++ APIs.
  *
  * ICU Text Access allows other formats, such as UTF-8 or non-contiguous
  * UTF-16 strings, to be placed in a UText wrapper and then passed to ICU services.
  *
  * There are three general classes of usage for UText:
  *
  *     Application Level Use.  This is the simplest usage - applications would
  *     use one of the utext_open() functions on their input text, and pass
  *     the resulting UText to the desired ICU service.
  *
  *     Second is usage in ICU Services, such as break iteration, that will need to
  *     operate on input presented to them as a UText.  These implementations
  *     will need to use the iteration and related UText functions to gain
  *     access to the actual text.
  *
  *     The third class of UText users are "text providers."  These are the
  *     UText implementations for the various text storage formats.  An application
  *     or system with a unique text storage format can implement a set of
  *     UText provider functions for that format, which will then allow
  *     ICU services to operate on that format.
  *
  *
  * <em>Iterating over text</em>
  *
  * Here is sample code for a forward iteration over the contents of a UText
  *
  * \code
  *    UChar32  c;
  *    UText    *ut = whatever();
  *
  *    for (c=utext_next32From(ut, 0); c>=0; c=utext_next32(ut)) {
  *       // do whatever with the codepoint c here.
  *    }
  * \endcode
  *
  * And here is similar code to iterate in the reverse direction, from the end
  * of the text towards the beginning.
  *
  * \code
  *    UChar32  c;
  *    UText    *ut = whatever();
  *    int      textLength = utext_nativeLength(ut);
  *    for (c=utext_previous32From(ut, textLength); c>=0; c=utext_previous32(ut)) {
  *       // do whatever with the codepoint c here.
  *    }
  * \endcode
  *
  * <em>Characters and Indexing</em>
  *
  * Indexing into text by UText functions is nearly always in terms of the native
  * indexing of the underlying text storage.  The storage format could be UTF-8
  * or UTF-32, for example.  When coding to the UText access API, no assumptions
  * can be made regarding the size of characters, or how far an index
  * may move when iterating between characters.
  *
  * All indices supplied to UText functions are pinned to the length of the
  * text.  An out-of-bounds index is not considered to be an error, but is
  * adjusted to be in the range  0 <= index <= length of input text.
  *
  *
  * When an index position is returned from a UText function, it will be
  * a native index to the underlying text.  In the case of multi-unit characters,
  * it will  always refer to the first position of the character,
  * never to the interior.  This is essentially the same thing as saying that
  * a returned index will always point to a boundary between characters.
  *
  * When a native index is supplied to a UText function, all indices that
  * refer to any part of a multi-unit character representation are considered
  * to be equivalent.  In the case of multi-unit characters, an incoming index
  * will be logically normalized to refer to the start of the character.
  * 
  * It is possible to test whether a native index is on a code point boundary
  * by doing a utext_setNativeIndex() followed by a utext_getNativeIndex().
  * If the index is returned unchanged, it was on a code point boundary.  If
  * an adjusted index is returned, the original index referred to the
  * interior of a character.
  *
  * <em>Conventions for calling UText functions</em>
  *
  * Most UText access functions have as their first parameter a (UText *) pointer,
  * which specifies the UText to be used.  Unless otherwise noted, the
  * pointer must refer to a valid, open UText.  Attempting to
  * use a closed UText or passing a NULL pointer is a programming error and
  * will produce undefined results or NULL pointer exceptions.
  * 
  * The UText_Open family of functions can either open an existing (closed)
  * UText, or heap allocate a new UText.  Here is sample code for creating
  * a stack-allocated UText.
  *
  * \code
  *    char     *s = whatever();  // A utf-8 string 
  *    U_ErrorCode status = U_ZERO_ERROR;
  *    UText    ut = UTEXT_INITIALIZER;
  *    utext_openUTF8(ut, s, -1, &status);
  *    if (U_FAILURE(status)) {
  *        // error handling
  *    } else {
  *        // work with the UText
  *    }
  * \endcode
  *
  * Any existing UText passed to an open function _must_ have been initialized, 
  * either by the UTEXT_INITIALIZER, or by having been originally heap-allocated
  * by an open function.  Passing NULL will cause the open function to
  * heap-allocate and fully initialize a new UText.
  *
  */
 
 
 
 #include "unicode/utypes.h"
 #include "unicode/uchar.h"
 #if U_SHOW_CPLUSPLUS_API
 #include "unicode/localpointer.h"
 #include "unicode/rep.h"
 #include "unicode/unistr.h"
 #include "unicode/chariter.h"
 #endif
 
 
 U_CDECL_BEGIN
 
 struct UText;
 typedef struct UText UText; /**< C typedef for struct UText. @stable ICU 3.6 */
 
 
 /***************************************************************************************
  *
  *   C Functions for creating UText wrappers around various kinds of text strings.
  *
  ****************************************************************************************/
 
 
 /**
   * Close function for UText instances.
   * Cleans up, releases any resources being held by an open UText.
   * <p>
   *   If the UText was originally allocated by one of the utext_open functions,
   *   the storage associated with the utext will also be freed.
   *   If the UText storage originated with the application, as it would with
   *   a local or static instance, the storage will not be deleted.
   *
   *   An open UText can be reset to refer to new string by using one of the utext_open()
   *   functions without first closing the UText.  
   *
   * @param ut  The UText to be closed.
   * @return    NULL if the UText struct was deleted by the close.  If the UText struct
   *            was originally provided by the caller to the open function, it is
   *            returned by this function, and may be safely used again in
   *            a subsequent utext_open.
   *
   * @stable ICU 3.4
   */
 U_CAPI UText * U_EXPORT2
 utext_close(UText *ut);
 
 /**
  * Open a read-only UText implementation for UTF-8 strings.
  * 
  * \htmlonly
  * Any invalid UTF-8 in the input will be handled in this way:
  * a sequence of bytes that has the form of a truncated, but otherwise valid,
  * UTF-8 sequence will be replaced by a single unicode replacement character, \uFFFD. 
  * Any other illegal bytes will each be replaced by a \uFFFD.
  * \endhtmlonly
  * 
  * @param ut     Pointer to a UText struct.  If NULL, a new UText will be created.
  *               If non-NULL, must refer to an initialized UText struct, which will then
  *               be reset to reference the specified UTF-8 string.
  * @param s      A UTF-8 string.  Must not be NULL.
  * @param length The length of the UTF-8 string in bytes, or -1 if the string is
  *               zero terminated.
  * @param status Errors are returned here.
  * @return       A pointer to the UText.  If a pre-allocated UText was provided, it
  *               will always be used and returned.
  * @stable ICU 3.4
  */
 U_CAPI UText * U_EXPORT2
 utext_openUTF8(UText *ut, const char *s, int64_t length, UErrorCode *status);
 
 
 /**
  * Open a read-only UText for UChar * string.
  * 
  * @param ut     Pointer to a UText struct.  If NULL, a new UText will be created.
  *               If non-NULL, must refer to an initialized UText struct, which will then
  *               be reset to reference the specified UChar string.
  * @param s      A UChar (UTF-16) string
  * @param length The number of UChars in the input string, or -1 if the string is
  *               zero terminated.
  * @param status Errors are returned here.
  * @return       A pointer to the UText.  If a pre-allocated UText was provided, it
  *               will always be used and returned.
  * @stable ICU 3.4
  */
 U_CAPI UText * U_EXPORT2
 utext_openUChars(UText *ut, const UChar *s, int64_t length, UErrorCode *status);
 
 
 #if U_SHOW_CPLUSPLUS_API
 /**
  * Open a writable UText for a non-const UnicodeString. 
  * 
  * @param ut      Pointer to a UText struct.  If nullptr, a new UText will be created.
  *                 If non-nullptr, must refer to an initialized UText struct, which will then
  *                 be reset to reference the specified input string.
  * @param s       A UnicodeString.
  * @param status Errors are returned here.
  * @return        Pointer to the UText.  If a UText was supplied as input, this
  *                 will always be used and returned.
  * @stable ICU 3.4
  */
 U_CAPI UText * U_EXPORT2
 utext_openUnicodeString(UText *ut, icu::UnicodeString *s, UErrorCode *status);
 
 
 /**
  * Open a UText for a const UnicodeString.   The resulting UText will not be writable.
  * 
  * @param ut    Pointer to a UText struct.  If nullptr, a new UText will be created.
  *               If non-nullptr, must refer to an initialized UText struct, which will then
  *               be reset to reference the specified input string.
  * @param s      A const UnicodeString to be wrapped.
  * @param status Errors are returned here.
  * @return       Pointer to the UText.  If a UText was supplied as input, this
  *               will always be used and returned.
  * @stable ICU 3.4
  */
 U_CAPI UText * U_EXPORT2
 utext_openConstUnicodeString(UText *ut, const icu::UnicodeString *s, UErrorCode *status);
 
 
 /**
  * Open a writable UText implementation for an ICU Replaceable object.
  * @param ut    Pointer to a UText struct.  If nullptr, a new UText will be created.
  *               If non-nullptr, must refer to an already existing UText, which will then
  *               be reset to reference the specified replaceable text.
  * @param rep    A Replaceable text object.
  * @param status Errors are returned here.
  * @return       Pointer to the UText.  If a UText was supplied as input, this
  *               will always be used and returned.
  * @see Replaceable
  * @stable ICU 3.4
  */
 U_CAPI UText * U_EXPORT2
 utext_openReplaceable(UText *ut, icu::Replaceable *rep, UErrorCode *status);
 
 /**
  * Open a  UText implementation over an ICU CharacterIterator.
  * @param ut    Pointer to a UText struct.  If nullptr, a new UText will be created.
  *               If non-nullptr, must refer to an already existing UText, which will then
  *               be reset to reference the specified replaceable text.
  * @param ci     A Character Iterator.
  * @param status Errors are returned here.
  * @return       Pointer to the UText.  If a UText was supplied as input, this
  *               will always be used and returned.
  * @see Replaceable
  * @stable ICU 3.4
  */
 U_CAPI UText * U_EXPORT2
 utext_openCharacterIterator(UText *ut, icu::CharacterIterator *ci, UErrorCode *status);
 
 #endif
 
 
 /**
   *  Clone a UText.  This is much like opening a UText where the source text is itself
   *  another UText.
   *
   *  A deep clone will copy both the UText data structures and the underlying text.
   *  The original and cloned UText will operate completely independently; modifications
   *  made to the text in one will not affect the other.  Text providers are not
   *  required to support deep clones.  The user of clone() must check the status return
   *  and be prepared to handle failures.
   *
   *  The standard UText implementations for UTF8, UChar *, UnicodeString and
   *  Replaceable all support deep cloning.
   *
   *  The UText returned from a deep clone will be writable, assuming that the text
   *  provider is able to support writing, even if the source UText had been made
   *  non-writable by means of UText_freeze().
   *
   *  A shallow clone replicates only the UText data structures; it does not make
   *  a copy of the underlying text.  Shallow clones can be used as an efficient way to 
   *  have multiple iterators active in a single text string that is not being
   *  modified.
   *
   *  A shallow clone operation will not fail, barring truly exceptional conditions such
   *  as memory allocation failures.
   *
   *  Shallow UText clones should be avoided if the UText functions that modify the
   *  text are expected to be used, either on the original or the cloned UText.
   *  Any such modifications  can cause unpredictable behavior.  Read Only
   *  shallow clones provide some protection against errors of this type by
   *  disabling text modification via the cloned UText.
   *
   *  A shallow clone made with the readOnly parameter == false will preserve the 
   *  utext_isWritable() state of the source object.  Note, however, that
   *  write operations must be avoided while more than one UText exists that refer
   *  to the same underlying text.
   *
   *  A UText and its clone may be safely concurrently accessed by separate threads.
   *  This is true for read access only with shallow clones, and for both read and
   *  write access with deep clones.
   *  It is the responsibility of the Text Provider to ensure that this thread safety
   *  constraint is met.
   *
   *  @param dest   A UText struct to be filled in with the result of the clone operation,
   *                or NULL if the clone function should heap-allocate a new UText struct.
   *                If non-NULL, must refer to an already existing UText, which will then
   *                be reset to become the clone.
   *  @param src    The UText to be cloned.
   *  @param deep   true to request a deep clone, false for a shallow clone.
   *  @param readOnly true to request that the cloned UText have read only access to the 
   *                underlying text.  
 
   *  @param status Errors are returned here.  For deep clones, U_UNSUPPORTED_ERROR
   *                will be returned if the text provider is unable to clone the
   *                original text.
   *  @return       The newly created clone, or NULL if the clone operation failed.
   *  @stable ICU 3.4
   */
 U_CAPI UText * U_EXPORT2
 utext_clone(UText *dest, const UText *src, UBool deep, UBool readOnly, UErrorCode *status);
 
 
 /**
   *  Compare two UText objects for equality.
   *  UTexts are equal if they are iterating over the same text, and
   *    have the same iteration position within the text.
   *    If either or both of the parameters are NULL, the comparison is false.
   *
   *  @param a   The first of the two UTexts to compare.
   *  @param b   The other UText to be compared.
   *  @return    true if the two UTexts are equal.
   *  @stable ICU 3.6
   */
 U_CAPI UBool U_EXPORT2
 utext_equals(const UText *a, const UText *b);
 
 
 /*****************************************************************************
  *
  *   Functions to work with the text represented by a UText wrapper
  *
  *****************************************************************************/
 
 /**
   * Get the length of the text.  Depending on the characteristics
   * of the underlying text representation, this may be expensive.  
   * @see  utext_isLengthExpensive()
   *
   *
   * @param ut  the text to be accessed.
   * @return the length of the text, expressed in native units.
   *
   * @stable ICU 3.4
   */
 U_CAPI int64_t U_EXPORT2
 utext_nativeLength(UText *ut);
 
 /**
  *  Return true if calculating the length of the text could be expensive.
  *  Finding the length of NUL terminated strings is considered to be expensive.
  *
  *  Note that the value of this function may change
  *  as the result of other operations on a UText.
  *  Once the length of a string has been discovered, it will no longer
  *  be expensive to report it.
  *
  * @param ut the text to be accessed.
  * @return true if determining the length of the text could be time consuming.
  * @stable ICU 3.4
  */
 U_CAPI UBool U_EXPORT2
 utext_isLengthExpensive(const UText *ut);
 
 /**
  * Returns the code point at the requested index,
  * or U_SENTINEL (-1) if it is out of bounds.
  *
  * If the specified index points to the interior of a multi-unit
  * character - one of the trail bytes of a UTF-8 sequence, for example -
  * the complete code point will be returned.
  *
  * The iteration position will be set to the start of the returned code point.
  *
  * This function is roughly equivalent to the sequence
  *    utext_setNativeIndex(index);
  *    utext_current32();
  * (There is a subtle difference if the index is out of bounds by being less than zero - 
  * utext_setNativeIndex(negative value) sets the index to zero, after which utext_current()
  * will return the char at zero.  utext_char32At(negative index), on the other hand, will
  * return the U_SENTINEL value of -1.)
  * 
  * @param ut the text to be accessed
  * @param nativeIndex the native index of the character to be accessed.  If the index points
  *        to other than the first unit of a multi-unit character, it will be adjusted
  *        to the start of the character.
  * @return the code point at the specified index.
  * @stable ICU 3.4
  */
 U_CAPI UChar32 U_EXPORT2
 utext_char32At(UText *ut, int64_t nativeIndex);
 
 
 /**
  *
  * Get the code point at the current iteration position,
  * or U_SENTINEL (-1) if the iteration has reached the end of
  * the input text.
  *
  * @param ut the text to be accessed.
  * @return the Unicode code point at the current iterator position.
  * @stable ICU 3.4
  */
 U_CAPI UChar32 U_EXPORT2
 utext_current32(UText *ut);
 
 
 /**
  * Get the code point at the current iteration position of the UText, and
  * advance the position to the first index following the character.
  *
  * If the position is at the end of the text (the index following
  * the last character, which is also the length of the text), 
  * return U_SENTINEL (-1) and do not advance the index. 
  *
  * This is a post-increment operation.
  *
  * An inline macro version of this function, UTEXT_NEXT32(), 
  * is available for performance critical use.
  *
  * @param ut the text to be accessed.
  * @return the Unicode code point at the iteration position.
  * @see UTEXT_NEXT32
  * @stable ICU 3.4
  */
 U_CAPI UChar32 U_EXPORT2
 utext_next32(UText *ut);
 
 
 /**
  *  Move the iterator position to the character (code point) whose
  *  index precedes the current position, and return that character.
  *  This is a pre-decrement operation.
  *
  *  If the initial position is at the start of the text (index of 0) 
  *  return U_SENTINEL (-1), and leave the position unchanged.
  *
  *  An inline macro version of this function, UTEXT_PREVIOUS32(), 
  *  is available for performance critical use.
  *
  *  @param ut the text to be accessed.
  *  @return the previous UChar32 code point, or U_SENTINEL (-1) 
  *          if the iteration has reached the start of the text.
  *  @see UTEXT_PREVIOUS32
  *  @stable ICU 3.4
  */
 U_CAPI UChar32 U_EXPORT2
 utext_previous32(UText *ut);
 
 
 /**
   * Set the iteration index and return the code point at that index. 
   * Leave the iteration index at the start of the following code point.
   *
   * This function is the most efficient and convenient way to
   * begin a forward iteration.  The results are identical to the those
   * from the sequence
   * \code
   *    utext_setIndex();
   *    utext_next32();
   * \endcode
   *
   *  @param ut the text to be accessed.
   *  @param nativeIndex Iteration index, in the native units of the text provider.
   *  @return Code point which starts at or before index,
   *         or U_SENTINEL (-1) if it is out of bounds.
   * @stable ICU 3.4
   */
 U_CAPI UChar32 U_EXPORT2
 utext_next32From(UText *ut, int64_t nativeIndex);
 
 
 
 /**
   * Set the iteration index, and return the code point preceding the
   * one specified by the initial index.  Leave the iteration position
   * at the start of the returned code point.
   *
   * This function is the most efficient and convenient way to
   * begin a backwards iteration.
   *
   * @param ut the text to be accessed.
   * @param nativeIndex Iteration index in the native units of the text provider.
   * @return Code point preceding the one at the initial index,
   *         or U_SENTINEL (-1) if it is out of bounds.
   *
   * @stable ICU 3.4
   */
 U_CAPI UChar32 U_EXPORT2
 utext_previous32From(UText *ut, int64_t nativeIndex);
 
 /**
   * Get the current iterator position, which can range from 0 to 
   * the length of the text.
   * The position is a native index into the input text, in whatever format it
   * may have (possibly UTF-8 for example), and may not always be the same as
   * the corresponding UChar (UTF-16) index.
   * The returned position will always be aligned to a code point boundary. 
   *
   * @param ut the text to be accessed.
   * @return the current index position, in the native units of the text provider.
   * @stable ICU 3.4
   */
 U_CAPI int64_t U_EXPORT2
 utext_getNativeIndex(const UText *ut);
 
 /**
  * Set the current iteration position to the nearest code point
  * boundary at or preceding the specified index.
  * The index is in the native units of the original input text.
  * If the index is out of range, it will be pinned to be within
  * the range of the input text.
  * <p>
  * It will usually be more efficient to begin an iteration
  * using the functions utext_next32From() or utext_previous32From()
  * rather than setIndex().
  * <p>
  * Moving the index position to an adjacent character is best done
  * with utext_next32(), utext_previous32() or utext_moveIndex32().
  * Attempting to do direct arithmetic on the index position is
  * complicated by the fact that the size (in native units) of a
  * character depends on the underlying representation of the character
  * (UTF-8, UTF-16, UTF-32, arbitrary codepage), and is not
  * easily knowable.
  *
  * @param ut the text to be accessed.
  * @param nativeIndex the native unit index of the new iteration position.
  * @stable ICU 3.4
  */
 U_CAPI void U_EXPORT2
 utext_setNativeIndex(UText *ut, int64_t nativeIndex);
 
 /**
  * Move the iterator position by delta code points.  The number of code points
  * is a signed number; a negative delta will move the iterator backwards,
  * towards the start of the text.
  * <p>
  * The index is moved by <code>delta</code> code points
  * forward or backward, but no further backward than to 0 and
  * no further forward than to utext_nativeLength().
  * The resulting index value will be in between 0 and length, inclusive.
  *
  * @param ut the text to be accessed.
  * @param delta the signed number of code points to move the iteration position.
  * @return true if the position could be moved the requested number of positions while
  *              staying within the range [0 - text length].
  * @stable ICU 3.4
  */
 U_CAPI UBool U_EXPORT2
 utext_moveIndex32(UText *ut, int32_t delta);
 
 /**
  * Get the native index of the character preceding the current position.
  * If the iteration position is already at the start of the text, zero
  * is returned.
  * The value returned is the same as that obtained from the following sequence,
  * but without the side effect of changing the iteration position.
  *   
  * \code
  *    UText  *ut = whatever;
  *      ...
  *    utext_previous(ut)
  *    utext_getNativeIndex(ut);
  * \endcode
  *
  * This function is most useful during forwards iteration, where it will get the
  *   native index of the character most recently returned from utext_next().
  *
  * @param ut the text to be accessed
  * @return the native index of the character preceding the current index position,
  *         or zero if the current position is at the start of the text.
  * @stable ICU 3.6
  */
 U_CAPI int64_t U_EXPORT2
 utext_getPreviousNativeIndex(UText *ut); 
 
 
 /**
  *
  * Extract text from a UText into a UChar buffer.  The range of text to be extracted
  * is specified in the native indices of the UText provider.  These may not necessarily
  * be UTF-16 indices.
  * <p>
  * The size (number of 16 bit UChars) of the data to be extracted is returned.  The
  * full number of UChars is returned, even when the extracted text is truncated
  * because the specified buffer size is too small.
  * <p>
  * The extracted string will (if you are a user) / must (if you are a text provider)
  * be NUL-terminated if there is sufficient space in the destination buffer.  This
  * terminating NUL is not included in the returned length.
  * <p>
  * The iteration index is left at the position following the last extracted character.
  *
  * @param  ut    the UText from which to extract data.
  * @param  nativeStart the native index of the first character to extract.\
  *               If the specified index is out of range,
  *               it will be pinned to be within 0 <= index <= textLength
  * @param  nativeLimit the native string index of the position following the last
  *               character to extract.  If the specified index is out of range,
  *               it will be pinned to be within 0 <= index <= textLength.
  *               nativeLimit must be >= nativeStart.
  * @param  dest  the UChar (UTF-16) buffer into which the extracted text is placed
  * @param  destCapacity  The size, in UChars, of the destination buffer.  May be zero
  *               for precomputing the required size.
  * @param  status receives any error status.
  *         U_BUFFER_OVERFLOW_ERROR: the extracted text was truncated because the 
  *         buffer was too small.  Returns number of UChars for preflighting.
  * @return Number of UChars in the data to be extracted.  Does not include a trailing NUL.
  *
  * @stable ICU 3.4
  */
 U_CAPI int32_t U_EXPORT2
 utext_extract(UText *ut,
              int64_t nativeStart, int64_t nativeLimit,
              UChar *dest, int32_t destCapacity,
              UErrorCode *status);
 
 
 
 /************************************************************************************
  *
  *  #define inline versions of selected performance-critical text access functions
  *          Caution:  do not use auto increment++ or decrement-- expressions
  *                    as parameters to these macros.
  *
  *          For most use, where there is no extreme performance constraint, the
  *          normal, non-inline functions are a better choice.  The resulting code
  *          will be smaller, and, if the need ever arises, easier to debug.
  *
  *          These are implemented as #defines rather than real functions
  *          because there is no fully portable way to do inline functions in plain C.
  *
  ************************************************************************************/
 
 #ifndef U_HIDE_INTERNAL_API
 /**
  * inline version of utext_current32(), for performance-critical situations.
  *
  * Get the code point at the current iteration position of the UText.
  * Returns U_SENTINEL (-1) if the position is at the end of the
  * text.
  *
  * @internal ICU 4.4 technology preview
  */
 #define UTEXT_CURRENT32(ut)  \
     ((ut)->chunkOffset < (ut)->chunkLength && ((ut)->chunkContents)[(ut)->chunkOffset]<0xd800 ? \
     ((ut)->chunkContents)[((ut)->chunkOffset)] : utext_current32(ut))
 #endif  /* U_HIDE_INTERNAL_API */
 
 /**
  * inline version of utext_next32(), for performance-critical situations.
  *
  * Get the code point at the current iteration position of the UText, and
  * advance the position to the first index following the character.
  * This is a post-increment operation.
  * Returns U_SENTINEL (-1) if the position is at the end of the
  * text.
  *
  * @stable ICU 3.4
  */
 #define UTEXT_NEXT32(ut)  \
     ((ut)->chunkOffset < (ut)->chunkLength && ((ut)->chunkContents)[(ut)->chunkOffset]<0xd800 ? \
     ((ut)->chunkContents)[((ut)->chunkOffset)++] : utext_next32(ut))
 
 /**
  * inline version of utext_previous32(), for performance-critical situations.
  *
  *  Move the iterator position to the character (code point) whose
  *  index precedes the current position, and return that character.
  *  This is a pre-decrement operation.
  *  Returns U_SENTINEL (-1) if the position is at the start of the  text.
  *
  * @stable ICU 3.4
  */
 #define UTEXT_PREVIOUS32(ut)  \
     ((ut)->chunkOffset > 0 && \
      (ut)->chunkContents[(ut)->chunkOffset-1] < 0xd800 ? \
           (ut)->chunkContents[--((ut)->chunkOffset)]  :  utext_previous32(ut))
 
 /**
   *  inline version of utext_getNativeIndex(), for performance-critical situations.
   *
   * Get the current iterator position, which can range from 0 to 
   * the length of the text.
   * The position is a native index into the input text, in whatever format it
   * may have (possibly UTF-8 for example), and may not always be the same as
   * the corresponding UChar (UTF-16) index.
   * The returned position will always be aligned to a code point boundary. 
   *
   * @stable ICU 3.6
   */
 #define UTEXT_GETNATIVEINDEX(ut)                       \
     ((ut)->chunkOffset <= (ut)->nativeIndexingLimit?   \
         (ut)->chunkNativeStart+(ut)->chunkOffset :     \
         (ut)->pFuncs->mapOffsetToNative(ut))    
 
 /**
   *  inline version of utext_setNativeIndex(), for performance-critical situations.
   *
   * Set the current iteration position to the nearest code point
   * boundary at or preceding the specified index.
   * The index is in the native units of the original input text.
   * If the index is out of range, it will be pinned to be within
   * the range of the input text.
   *
   * @stable ICU 3.8
   */
 #define UTEXT_SETNATIVEINDEX(ut, ix) UPRV_BLOCK_MACRO_BEGIN { \
     int64_t __offset = (ix) - (ut)->chunkNativeStart; \
     if (__offset>=0 && __offset<(int64_t)(ut)->nativeIndexingLimit && (ut)->chunkContents[__offset]<0xdc00) { \
         (ut)->chunkOffset=(int32_t)__offset; \
     } else { \
         utext_setNativeIndex((ut), (ix)); \
     } \
 } UPRV_BLOCK_MACRO_END
 
 
 
 /************************************************************************************
  *
  *   Functions related to writing or modifying the text.
  *   These will work only with modifiable UTexts.  Attempting to
  *   modify a read-only UText will return an error status.
  *
  ************************************************************************************/
 
 
 /**
  *  Return true if the text can be written (modified) with utext_replace() or
  *  utext_copy().  For the text to be writable, the text provider must
  *  be of a type that supports writing and the UText must not be frozen.
  *
  *  Attempting to modify text when utext_isWriteable() is false will fail -
  *  the text will not be modified, and an error will be returned from the function
  *  that attempted the modification.
  *
  * @param  ut   the UText to be tested.
  * @return true if the text is modifiable.
  *
  * @see    utext_freeze()
  * @see    utext_replace()
  * @see    utext_copy()
  * @stable ICU 3.4
  *
  */
 U_CAPI UBool U_EXPORT2
 utext_isWritable(const UText *ut);
 
 
 /**
   * Test whether there is meta data associated with the text.
   * @see Replaceable::hasMetaData()
   *
   * @param ut The UText to be tested
   * @return true if the underlying text includes meta data.
   * @stable ICU 3.4
   */
 U_CAPI UBool U_EXPORT2
 utext_hasMetaData(const UText *ut);
 
 
 /**
  * Replace a range of the original text with a replacement text.
  *
  * Leaves the current iteration position at the position following the
  *  newly inserted replacement text.
  *
  * This function is only available on UText types that support writing,
  * that is, ones where utext_isWritable() returns true.
  *
  * When using this function, there should be only a single UText opened onto the
  * underlying native text string.  Behavior after a replace operation
  * on a UText is undefined for any other additional UTexts that refer to the
  * modified string.
  *
  * @param ut               the UText representing the text to be operated on.
  * @param nativeStart      the native index of the start of the region to be replaced
  * @param nativeLimit      the native index of the character following the region to be replaced.
  * @param replacementText  pointer to the replacement text
  * @param replacementLength length of the replacement text, or -1 if the text is NUL terminated.
  * @param status           receives any error status.  Possible errors include
  *                         U_NO_WRITE_PERMISSION
  *
  * @return The signed number of (native) storage units by which
  *         the length of the text expanded or contracted.
  *
  * @stable ICU 3.4
  */
 U_CAPI int32_t U_EXPORT2
 utext_replace(UText *ut,
              int64_t nativeStart, int64_t nativeLimit,
              const UChar *replacementText, int32_t replacementLength,
              UErrorCode *status);
 
 
 
 /**
  *
  * Copy or move a substring from one position to another within the text,
  * while retaining any metadata associated with the text.
  * This function is used to duplicate or reorder substrings.
  * The destination index must not overlap the source range.
  *
  * The text to be copied or moved is inserted at destIndex;
  * it does not replace or overwrite any existing text.
  *
  * The iteration position is left following the newly inserted text
  * at the destination position.
  *
  * This function is only available on UText types that support writing,
  * that is, ones where utext_isWritable() returns true.
  *
  * When using this function, there should be only a single UText opened onto the
  * underlying native text string.  Behavior after a copy operation
  * on a UText is undefined in any other additional UTexts that refer to the
  * modified string.
  *
  * @param ut           The UText representing the text to be operated on.
  * @param nativeStart  The native index of the start of the region to be copied or moved
  * @param nativeLimit  The native index of the character position following the region
  *                     to be copied.
  * @param destIndex    The native destination index to which the source substring is
  *                     copied or moved.
  * @param move         If true, then the substring is moved, not copied/duplicated.
  * @param status       receives any error status.  Possible errors include U_NO_WRITE_PERMISSION
  *                       
  * @stable ICU 3.4
  */
 U_CAPI void U_EXPORT2
 utext_copy(UText *ut,
           int64_t nativeStart, int64_t nativeLimit,
           int64_t destIndex,
           UBool move,
           UErrorCode *status);
 
 
 /**
   *  <p>
   *  Freeze a UText.  This prevents any modification to the underlying text itself
   *  by means of functions operating on this UText.
   *  </p>
   *  <p>
   *  Once frozen, a UText can not be unfrozen.  The intent is to ensure
   *  that a the text underlying a frozen UText wrapper cannot be modified via that UText.
   *  </p>
   *  <p>
   *  Caution:  freezing a UText will disable changes made via the specific
   *   frozen UText wrapper only; it will not have any effect on the ability to
   *   directly modify the text by bypassing the UText.  Any such backdoor modifications
   *   are always an error while UText access is occurring because the underlying
   *   text can get out of sync with UText's buffering.
   *  </p>
   *
   *  @param ut  The UText to be frozen.
   *  @see   utext_isWritable()
   *  @stable ICU 3.6
   */
 U_CAPI void U_EXPORT2
 utext_freeze(UText *ut);
 
 
 /**
  * UText provider properties (bit field indexes).
  *
  * @see UText
  * @stable ICU 3.4
  */
 enum {
     /**
      * It is potentially time consuming for the provider to determine the length of the text.
      * @stable ICU 3.4
      */
     UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE = 1,
     /**
      * Text chunks remain valid and usable until the text object is modified or
      * deleted, not just until the next time the access() function is called
      * (which is the default).
      * @stable ICU 3.4
      */
     UTEXT_PROVIDER_STABLE_CHUNKS = 2,
     /**
      * The provider supports modifying the text via the replace() and copy()
      * functions.
      * @see Replaceable
      * @stable ICU 3.4
      */
     UTEXT_PROVIDER_WRITABLE = 3,
     /**
      * There is meta data associated with the text.
      * @see Replaceable::hasMetaData()
      * @stable ICU 3.4
      */ 
     UTEXT_PROVIDER_HAS_META_DATA = 4,
     /**
      * Text provider owns the text storage.
      *  Generally occurs as the result of a deep clone of the UText.
      *  When closing the UText, the associated text must
      *  also be closed/deleted/freed/ whatever is appropriate.
      * @stable ICU 3.6
      */
      UTEXT_PROVIDER_OWNS_TEXT = 5
 };
 
 /**
   * Function type declaration for UText.clone().
   *
   *  clone a UText.  Much like opening a UText where the source text is itself
   *  another UText.
   *
   *  A deep clone will copy both the UText data structures and the underlying text.
   *  The original and cloned UText will operate completely independently; modifications
   *  made to the text in one will not effect the other.  Text providers are not
   *  required to support deep clones.  The user of clone() must check the status return
   *  and be prepared to handle failures.
   *
   *  A shallow clone replicates only the UText data structures; it does not make
   *  a copy of the underlying text.  Shallow clones can be used as an efficient way to 
   *  have multiple iterators active in a single text string that is not being
   *  modified.
   *
   *  A shallow clone operation must not fail except for truly exceptional conditions such
   *  as memory allocation failures.
   *
   *  A UText and its clone may be safely concurrently accessed by separate threads.
   *  This is true for both shallow and deep clones.
   *  It is the responsibility of the Text Provider to ensure that this thread safety
   *  constraint is met.
 
   *
   *  @param dest   A UText struct to be filled in with the result of the clone operation,
   *                or NULL if the clone function should heap-allocate a new UText struct.
   *  @param src    The UText to be cloned.
   *  @param deep   true to request a deep clone, false for a shallow clone.
   *  @param status Errors are returned here.  For deep clones, U_UNSUPPORTED_ERROR
   *                should be returned if the text provider is unable to clone the
   *                original text.
   *  @return       The newly created clone, or NULL if the clone operation failed.
   *
   * @stable ICU 3.4
   */
 typedef UText * U_CALLCONV
 UTextClone(UText *dest, const UText *src, UBool deep, UErrorCode *status);
 
 
 /**
  * Function type declaration for UText.nativeLength().
  *
  * @param ut the UText to get the length of.
  * @return the length, in the native units of the original text string.
  * @see UText
  * @stable ICU 3.4
  */
 typedef int64_t U_CALLCONV
 UTextNativeLength(UText *ut);
 
 /**
  * Function type declaration for UText.access().  Get the description of the text chunk
  *  containing the text at a requested native index.  The UText's iteration
  *  position will be left at the requested index.  If the index is out
  *  of bounds, the iteration position will be left at the start or end
  *  of the string, as appropriate.
  *
  *  Chunks must begin and end on code point boundaries.  A single code point
  *  comprised of multiple storage units must never span a chunk boundary.
  *
  *
  * @param ut          the UText being accessed.
  * @param nativeIndex Requested index of the text to be accessed.
  * @param forward     If true, then the returned chunk must contain text
  *                    starting from the index, so that start<=index<limit.
  *                    If false, then the returned chunk must contain text
  *                    before the index, so that start<index<=limit.
  * @return            True if the requested index could be accessed.  The chunk
  *                    will contain the requested text.
  *                    False value if a chunk cannot be accessed
  *                    (the requested index is out of bounds).
  *
  * @see UText
  * @stable ICU 3.4
  */
 typedef UBool U_CALLCONV
 UTextAccess(UText *ut, int64_t nativeIndex, UBool forward);
 
 /**
  * Function type declaration for UText.extract().
  *
  * Extract text from a UText into a UChar buffer.  The range of text to be extracted
  * is specified in the native indices of the UText provider.  These may not necessarily
  * be UTF-16 indices.
  * <p>
  * The size (number of 16 bit UChars) in the data to be extracted is returned.  The
  * full amount is returned, even when the specified buffer size is smaller.
  * <p>
  * The extracted string will (if you are a user) / must (if you are a text provider)
  * be NUL-terminated if there is sufficient space in the destination buffer.
  *
  * @param  ut            the UText from which to extract data.
  * @param  nativeStart   the native index of the first character to extract.
  * @param  nativeLimit   the native string index of the position following the last
  *                       character to extract.
  * @param  dest          the UChar (UTF-16) buffer into which the extracted text is placed
  * @param  destCapacity  The size, in UChars, of the destination buffer.  May be zero
  *                       for precomputing the required size.
  * @param  status        receives any error status.
  *                       If U_BUFFER_OVERFLOW_ERROR: Returns number of UChars for
  *                       preflighting.
  * @return Number of UChars in the data.  Does not include a trailing NUL.
  *
  * @stable ICU 3.4
  */
 typedef int32_t U_CALLCONV
 UTextExtract(UText *ut,
              int64_t nativeStart, int64_t nativeLimit,
              UChar *dest, int32_t destCapacity,
              UErrorCode *status);
 
 /**
  * Function type declaration for UText.replace().
  *
  * Replace a range of the original text with a replacement text.
  *
  * Leaves the current iteration position at the position following the
  *  newly inserted replacement text.
  *
  * This function need only be implemented on UText types that support writing.
  *
  * When using this function, there should be only a single UText opened onto the
  * underlying native text string.  The function is responsible for updating the
  * text chunk within the UText to reflect the updated iteration position,
  * taking into account any changes to the underlying string's structure caused
  * by the replace operation.
  *
  * @param ut               the UText representing the text to be operated on.
  * @param nativeStart      the index of the start of the region to be replaced
  * @param nativeLimit      the index of the character following the region to be replaced.
  * @param replacementText  pointer to the replacement text
  * @param replacmentLength length of the replacement text in UChars, or -1 if the text is NUL terminated.
  * @param status           receives any error status.  Possible errors include
  *                         U_NO_WRITE_PERMISSION
  *
  * @return The signed number of (native) storage units by which
  *         the length of the text expanded or contracted.
  *
  * @stable ICU 3.4
  */
 typedef int32_t U_CALLCONV
 UTextReplace(UText *ut,
              int64_t nativeStart, int64_t nativeLimit,
              const UChar *replacementText, int32_t replacmentLength,
              UErrorCode *status);
 
 /**
  * Function type declaration for UText.copy().
  *
  * Copy or move a substring from one position to another within the text,
  * while retaining any metadata associated with the text.
  * This function is used to duplicate or reorder substrings.
  * The destination index must not overlap the source range.
  *
  * The text to be copied or moved is inserted at destIndex;
  * it does not replace or overwrite any existing text.
  *
  * This function need only be implemented for UText types that support writing.
  *
  * When using this function, there should be only a single UText opened onto the
  * underlying native text string.  The function is responsible for updating the
  * text chunk within the UText to reflect the updated iteration position,
  * taking into account any changes to the underlying string's structure caused
  * by the replace operation.
  *
  * @param ut           The UText representing the text to be operated on.
  * @param nativeStart  The index of the start of the region to be copied or moved
  * @param nativeLimit  The index of the character following the region to be replaced.
  * @param nativeDest   The destination index to which the source substring is copied or moved.
  * @param move         If true, then the substring is moved, not copied/duplicated.
  * @param status       receives any error status.  Possible errors include U_NO_WRITE_PERMISSION
  *
  * @stable ICU 3.4
  */
 typedef void U_CALLCONV
 UTextCopy(UText *ut,
           int64_t nativeStart, int64_t nativeLimit,
           int64_t nativeDest,
           UBool move,
           UErrorCode *status);
 
 /**
  * Function type declaration for UText.mapOffsetToNative().
  * Map from the current UChar offset within the current text chunk to
  *  the corresponding native index in the original source text.
  *
  * This is required only for text providers that do not use native UTF-16 indexes.
  *
  * @param ut     the UText.
  * @return Absolute (native) index corresponding to chunkOffset in the current chunk.
  *         The returned native index should always be to a code point boundary.
  *
  * @stable ICU 3.4
  */
 typedef int64_t U_CALLCONV
 UTextMapOffsetToNative(const UText *ut);
 
 /**
  * Function type declaration for UText.mapIndexToUTF16().
  * Map from a native index to a UChar offset within a text chunk.
  * Behavior is undefined if the native index does not fall within the
  *   current chunk.
  *
  * This function is required only for text providers that do not use native UTF-16 indexes.
  *
  * @param ut          The UText containing the text chunk.
  * @param nativeIndex Absolute (native) text index, chunk->start<=index<=chunk->limit.
  * @return            Chunk-relative UTF-16 offset corresponding to the specified native
  *                    index.
  *
  * @stable ICU 3.4
  */
 typedef int32_t U_CALLCONV
 UTextMapNativeIndexToUTF16(const UText *ut, int64_t nativeIndex);
 
 
 /**
  * Function type declaration for UText.utextClose().
  *
  * A Text Provider close function is only required for provider types that make
  *  allocations in their open function (or other functions) that must be 
  *  cleaned when the UText is closed.
  *
  * The allocation of the UText struct itself and any "extra" storage
  * associated with the UText is handled by the common UText implementation
  * and does not require provider specific cleanup in a close function.
  *
  * Most UText provider implementations do not need to implement this function.
  *
  * @param ut A UText object to be closed.
  *
  * @stable ICU 3.4
  */
 typedef void U_CALLCONV
 UTextClose(UText *ut);
 
 
 /**
   *   (public)  Function dispatch table for UText.
   *             Conceptually very much like a C++ Virtual Function Table.
   *             This struct defines the organization of the table.
   *             Each text provider implementation must provide an
   *              actual table that is initialized with the appropriate functions
   *              for the type of text being handled.
   *   @stable ICU 3.6
   */
 struct UTextFuncs {
     /**
      *   (public)  Function table size, sizeof(UTextFuncs)
      *             Intended for use should the table grow to accommodate added
      *             functions in the future, to allow tests for older format
      *             function tables that do not contain the extensions.
      *
      *             Fields are placed for optimal alignment on
      *             32/64/128-bit-pointer machines, by normally grouping together
      *             4 32-bit fields,
      *             4 pointers,
      *             2 64-bit fields
      *             in sequence.
      *   @stable ICU 3.6
      */
     int32_t       tableSize;
 
     /**
       *   (private)  Alignment padding.
       *              Do not use, reserved for use by the UText framework only.
       *   @internal
       */
     int32_t       reserved1, /** @internal */ reserved2, /** @internal */ reserved3;
 
 
     /**
      * (public) Function pointer for UTextClone
      *
      * @see UTextClone
      * @stable ICU 3.6
      */
     UTextClone *clone;
 
     /**
      * (public) function pointer for UTextLength
      * May be expensive to compute!
      *
      * @see UTextLength
      * @stable ICU 3.6
      */
     UTextNativeLength *nativeLength;
 
     /**
      * (public) Function pointer for UTextAccess.
      *
      * @see UTextAccess
      * @stable ICU 3.6
      */
     UTextAccess *access;
 
     /**
      * (public) Function pointer for UTextExtract.
      *
      * @see UTextExtract
      * @stable ICU 3.6
      */
     UTextExtract *extract;
 
     /**
      * (public) Function pointer for UTextReplace.
      *
      * @see UTextReplace
      * @stable ICU 3.6
      */
     UTextReplace *replace;
 
     /**
      * (public) Function pointer for UTextCopy.
      *
      * @see UTextCopy
      * @stable ICU 3.6
      */
     UTextCopy *copy;
 
     /**
      * (public) Function pointer for UTextMapOffsetToNative.
      *
      * @see UTextMapOffsetToNative
      * @stable ICU 3.6
      */
     UTextMapOffsetToNative *mapOffsetToNative;
 
     /**
      * (public) Function pointer for UTextMapNativeIndexToUTF16.
      *
      * @see UTextMapNativeIndexToUTF16
      * @stable ICU 3.6
      */
     UTextMapNativeIndexToUTF16 *mapNativeIndexToUTF16;
 
     /**
      * (public) Function pointer for UTextClose.
       *
       * @see UTextClose
       * @stable ICU 3.6
       */
     UTextClose  *close;
 
     /**
       * (private)  Spare function pointer
       * @internal
       */
     UTextClose  *spare1;
     
     /**
       * (private)  Spare function pointer
       * @internal
       */
     UTextClose  *spare2;
 
     /**
       * (private)  Spare function pointer
       * @internal
       */
     UTextClose  *spare3;
 
 };
 /**
  * Function dispatch table for UText
  * @see UTextFuncs
  */
 typedef struct UTextFuncs UTextFuncs;
 
  /**
   *   UText struct.  Provides the interface between the generic UText access code
   *                  and the UText provider code that works on specific kinds of
   *                  text  (UTF-8, noncontiguous UTF-16, whatever.)
   *
   *                  Applications that are using predefined types of text providers
   *                  to pass text data to ICU services will have no need to view the
   *                  internals of the UText structs that they open.
   *
   * @stable ICU 3.6
   */
 struct UText {
     /**
      *     (private)  Magic.  Used to help detect when UText functions are handed
      *                        invalid or uninitialized UText structs.
      *                        utext_openXYZ() functions take an initialized,
      *                        but not necessarily open, UText struct as an
      *                        optional fill-in parameter.  This magic field
      *                        is used to check for that initialization.
      *                        Text provider close functions must NOT clear
      *                        the magic field because that would prevent
      *                        reuse of the UText struct.
      * @internal
      */
     uint32_t       magic;
 
 
     /**
      *     (private)  Flags for managing the allocation and freeing of
      *                memory associated with this UText.
      * @internal
      */
     int32_t        flags;
 
 
     /**
       *  Text provider properties.  This set of flags is maintained by the
       *                             text provider implementation.
       *  @stable ICU 3.4
       */
     int32_t         providerProperties;
 
     /**
      * (public) sizeOfStruct=sizeof(UText)
      * Allows possible backward compatible extension.
      *
      * @stable ICU 3.4
      */
     int32_t         sizeOfStruct;
     
     /* ------ 16 byte alignment boundary -----------  */
     
 
     /**
       *  (protected) Native index of the first character position following
       *              the current chunk.
       *  @stable ICU 3.6
       */
     int64_t         chunkNativeLimit;
 
     /**
      *   (protected)  Size in bytes of the extra space (pExtra).
      *  @stable ICU 3.4
      */
     int32_t        extraSize;
 
     /**
       *    (protected) The highest chunk offset where native indexing and
       *    chunk (UTF-16) indexing correspond.  For UTF-16 sources, value
       *    will be equal to chunkLength.
       *
       *    @stable ICU 3.6
       */
     int32_t         nativeIndexingLimit;
 
     /* ---- 16 byte alignment boundary------ */
     
     /**
      *  (protected) Native index of the first character in the text chunk.
      *  @stable ICU 3.6
      */
     int64_t         chunkNativeStart;
 
     /**
      *  (protected) Current iteration position within the text chunk (UTF-16 buffer).
      *  This is the index to the character that will be returned by utext_next32().
      *  @stable ICU 3.6
      */
     int32_t         chunkOffset;
 
     /**
      *  (protected) Length the text chunk (UTF-16 buffer), in UChars.
      *  @stable ICU 3.6
      */
     int32_t         chunkLength;
 
     /* ---- 16  byte alignment boundary-- */
     
 
     /**
      *  (protected)  pointer to a chunk of text in UTF-16 format.
      *  May refer either to original storage of the source of the text, or
      *  if conversion was required, to a buffer owned by the UText.
      *  @stable ICU 3.6
      */
     const UChar    *chunkContents;
 
      /**
       * (public)     Pointer to Dispatch table for accessing functions for this UText.
       * @stable ICU 3.6
       */
     const UTextFuncs     *pFuncs;
 
     /**
      *  (protected)  Pointer to additional space requested by the
      *               text provider during the utext_open operation.
      * @stable ICU 3.4
      */
     void          *pExtra;
 
     /**
      * (protected) Pointer to string or text-containing object or similar.
      * This is the source of the text that this UText is wrapping, in a format
      *  that is known to the text provider functions.
      * @stable ICU 3.4
      */
     const void   *context;
 
     /* --- 16 byte alignment boundary--- */
 
     /**
      * (protected) Pointer fields available for use by the text provider.
      * Not used by UText common code.
      * @stable ICU 3.6
      */
     const void     *p; 
     /**
      * (protected) Pointer fields available for use by the text provider.
      * Not used by UText common code.
      * @stable ICU 3.6
      */
     const void     *q;
      /**
      * (protected) Pointer fields available for use by the text provider.
      * Not used by UText common code.
      * @stable ICU 3.6
       */
     const void     *r;
 
     /**
       *  Private field reserved for future use by the UText framework
       *     itself.  This is not to be touched by the text providers.
       * @internal ICU 3.4
       */
     void           *privP;
 
 
     /* --- 16 byte alignment boundary--- */
     
 
     /**
       * (protected) Integer field reserved for use by the text provider.
       * Not used by the UText framework, or by the client (user) of the UText.
       * @stable ICU 3.4
       */
     int64_t         a;
 
     /**
       * (protected) Integer field reserved for use by the text provider.
       * Not used by the UText framework, or by the client (user) of the UText.
       * @stable ICU 3.4
       */
     int32_t         b;
 
     /**
       * (protected) Integer field reserved for use by the text provider.
       * Not used by the UText framework, or by the client (user) of the UText.
       * @stable ICU 3.4
       */
     int32_t         c;
 
     /*  ---- 16 byte alignment boundary---- */
 
 
     /**
       *  Private field reserved for future use by the UText framework
       *     itself.  This is not to be touched by the text providers.
       * @internal ICU 3.4
       */
     int64_t         privA;
     /**
       *  Private field reserved for future use by the UText framework
       *     itself.  This is not to be touched by the text providers.
       * @internal ICU 3.4
       */
     int32_t         privB;
     /**
       *  Private field reserved for future use by the UText framework
       *     itself.  This is not to be touched by the text providers.
       * @internal ICU 3.4
       */
     int32_t         privC;
 };
 
 
 /**
  *  Common function for use by Text Provider implementations to allocate and/or initialize
  *  a new UText struct.  To be called in the implementation of utext_open() functions.
  *  If the supplied UText parameter is null, a new UText struct will be allocated on the heap.
  *  If the supplied UText is already open, the provider's close function will be called
  *  so that the struct can be reused by the open that is in progress.
  *
  * @param ut   pointer to a UText struct to be re-used, or null if a new UText
  *             should be allocated.
  * @param extraSpace The amount of additional space to be allocated as part
  *             of this UText, for use by types of providers that require
  *             additional storage.
  * @param status Errors are returned here.
  * @return pointer to the UText, allocated if necessary, with extra space set up if requested.
  * @stable ICU 3.4
  */
 U_CAPI UText * U_EXPORT2
 utext_setup(UText *ut, int32_t extraSpace, UErrorCode *status);
 
 // do not use #ifndef U_HIDE_INTERNAL_API around the following!
 /**
   * @internal
   *  Value used to help identify correctly initialized UText structs.
   *  Note:  must be publicly visible so that UTEXT_INITIALIZER can access it.
   */
 enum {
     UTEXT_MAGIC = 0x345ad82c
 };
 
 /**
  * initializer to be used with local (stack) instances of a UText
  *  struct.  UText structs must be initialized before passing
  *  them to one of the utext_open functions.
  *
  * @stable ICU 3.6
  */
 #define UTEXT_INITIALIZER {                                        \
                   UTEXT_MAGIC,          /* magic                */ \
                   0,                    /* flags                */ \
                   0,                    /* providerProps        */ \
                   sizeof(UText),        /* sizeOfStruct         */ \
                   0,                    /* chunkNativeLimit     */ \
                   0,                    /* extraSize            */ \
                   0,                    /* nativeIndexingLimit  */ \
                   0,                    /* chunkNativeStart     */ \
                   0,                    /* chunkOffset          */ \
                   0,                    /* chunkLength          */ \
                   NULL,                 /* chunkContents        */ \
                   NULL,                 /* pFuncs               */ \
                   NULL,                 /* pExtra               */ \
                   NULL,                 /* context              */ \
                   NULL, NULL, NULL,     /* p, q, r              */ \
                   NULL,                 /* privP                */ \
                   0, 0, 0,              /* a, b, c              */ \
                   0, 0, 0               /* privA,B,C,           */ \
                   }
 
 
 U_CDECL_END
 
 
 #if U_SHOW_CPLUSPLUS_API
 
 U_NAMESPACE_BEGIN
 
 /**
  * \class LocalUTextPointer
  * "Smart pointer" class, closes a UText via utext_close().
  * For most methods see the LocalPointerBase base class.
  *
  * @see LocalPointerBase
  * @see LocalPointer
  * @stable ICU 4.4
  */
 U_DEFINE_LOCAL_OPEN_POINTER(LocalUTextPointer, UText, utext_close);
 
 U_NAMESPACE_END
 
 #endif
 
 
 #endif

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