webengine/osswebengine/WebKit/icu/unicode/unorm.h
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     1 /*
       
     2 *******************************************************************************
       
     3 * Copyright (c) 1996-2004, International Business Machines Corporation
       
     4 *               and others. All Rights Reserved.
       
     5 *******************************************************************************
       
     6 * File unorm.h
       
     7 *
       
     8 * Created by: Vladimir Weinstein 12052000
       
     9 *
       
    10 * Modification history :
       
    11 *
       
    12 * Date        Name        Description
       
    13 * 02/01/01    synwee      Added normalization quickcheck enum and method.
       
    14 */
       
    15 #ifndef UNORM_H
       
    16 #define UNORM_H
       
    17 
       
    18 #include "unicode/utypes.h"
       
    19 
       
    20 #if !UCONFIG_NO_NORMALIZATION
       
    21 
       
    22 #include "unicode/uiter.h"
       
    23 
       
    24 /**
       
    25  * \file
       
    26  * \brief C API: Unicode Normalization 
       
    27  *
       
    28  * <h2>Unicode normalization API</h2>
       
    29  *
       
    30  * <code>unorm_normalize</code> transforms Unicode text into an equivalent composed or
       
    31  * decomposed form, allowing for easier sorting and searching of text.
       
    32  * <code>unorm_normalize</code> supports the standard normalization forms described in
       
    33  * <a href="http://www.unicode.org/unicode/reports/tr15/" target="unicode">
       
    34  * Unicode Standard Annex #15 &#8212; Unicode Normalization Forms</a>.
       
    35  *
       
    36  * Characters with accents or other adornments can be encoded in
       
    37  * several different ways in Unicode.  For example, take the character A-acute.
       
    38  * In Unicode, this can be encoded as a single character (the
       
    39  * "composed" form):
       
    40  *
       
    41  * \code
       
    42  *      00C1    LATIN CAPITAL LETTER A WITH ACUTE
       
    43  * \endcode
       
    44  *
       
    45  * or as two separate characters (the "decomposed" form):
       
    46  *
       
    47  * \code
       
    48  *      0041    LATIN CAPITAL LETTER A
       
    49  *      0301    COMBINING ACUTE ACCENT
       
    50  * \endcode
       
    51  *
       
    52  * To a user of your program, however, both of these sequences should be
       
    53  * treated as the same "user-level" character "A with acute accent".  When you are searching or
       
    54  * comparing text, you must ensure that these two sequences are treated 
       
    55  * equivalently.  In addition, you must handle characters with more than one
       
    56  * accent.  Sometimes the order of a character's combining accents is
       
    57  * significant, while in other cases accent sequences in different orders are
       
    58  * really equivalent.
       
    59  *
       
    60  * Similarly, the string "ffi" can be encoded as three separate letters:
       
    61  *
       
    62  * \code
       
    63  *      0066    LATIN SMALL LETTER F
       
    64  *      0066    LATIN SMALL LETTER F
       
    65  *      0069    LATIN SMALL LETTER I
       
    66  * \endcode
       
    67  *
       
    68  * or as the single character
       
    69  *
       
    70  * \code
       
    71  *      FB03    LATIN SMALL LIGATURE FFI
       
    72  * \endcode
       
    73  *
       
    74  * The ffi ligature is not a distinct semantic character, and strictly speaking
       
    75  * it shouldn't be in Unicode at all, but it was included for compatibility
       
    76  * with existing character sets that already provided it.  The Unicode standard
       
    77  * identifies such characters by giving them "compatibility" decompositions
       
    78  * into the corresponding semantic characters.  When sorting and searching, you
       
    79  * will often want to use these mappings.
       
    80  *
       
    81  * <code>unorm_normalize</code> helps solve these problems by transforming text into the
       
    82  * canonical composed and decomposed forms as shown in the first example above.  
       
    83  * In addition, you can have it perform compatibility decompositions so that 
       
    84  * you can treat compatibility characters the same as their equivalents.
       
    85  * Finally, <code>unorm_normalize</code> rearranges accents into the proper canonical
       
    86  * order, so that you do not have to worry about accent rearrangement on your
       
    87  * own.
       
    88  *
       
    89  * Form FCD, "Fast C or D", is also designed for collation.
       
    90  * It allows to work on strings that are not necessarily normalized
       
    91  * with an algorithm (like in collation) that works under "canonical closure", i.e., it treats precomposed
       
    92  * characters and their decomposed equivalents the same.
       
    93  *
       
    94  * It is not a normalization form because it does not provide for uniqueness of representation. Multiple strings
       
    95  * may be canonically equivalent (their NFDs are identical) and may all conform to FCD without being identical
       
    96  * themselves.
       
    97  *
       
    98  * The form is defined such that the "raw decomposition", the recursive canonical decomposition of each character,
       
    99  * results in a string that is canonically ordered. This means that precomposed characters are allowed for as long
       
   100  * as their decompositions do not need canonical reordering.
       
   101  *
       
   102  * Its advantage for a process like collation is that all NFD and most NFC texts - and many unnormalized texts -
       
   103  * already conform to FCD and do not need to be normalized (NFD) for such a process. The FCD quick check will
       
   104  * return UNORM_YES for most strings in practice.
       
   105  *
       
   106  * unorm_normalize(UNORM_FCD) may be implemented with UNORM_NFD.
       
   107  *
       
   108  * For more details on FCD see the collation design document:
       
   109  * http://oss.software.ibm.com/cvs/icu/~checkout~/icuhtml/design/collation/ICU_collation_design.htm
       
   110  *
       
   111  * ICU collation performs either NFD or FCD normalization automatically if normalization
       
   112  * is turned on for the collator object.
       
   113  * Beyond collation and string search, normalized strings may be useful for string equivalence comparisons,
       
   114  * transliteration/transcription, unique representations, etc.
       
   115  *
       
   116  * The W3C generally recommends to exchange texts in NFC.
       
   117  * Note also that most legacy character encodings use only precomposed forms and often do not
       
   118  * encode any combining marks by themselves. For conversion to such character encodings the
       
   119  * Unicode text needs to be normalized to NFC.
       
   120  * For more usage examples, see the Unicode Standard Annex.
       
   121  */
       
   122 
       
   123 /**
       
   124  * Constants for normalization modes.
       
   125  * @stable ICU 2.0
       
   126  */
       
   127 typedef enum {
       
   128   /** No decomposition/composition. @stable ICU 2.0 */
       
   129   UNORM_NONE = 1, 
       
   130   /** Canonical decomposition. @stable ICU 2.0 */
       
   131   UNORM_NFD = 2,
       
   132   /** Compatibility decomposition. @stable ICU 2.0 */
       
   133   UNORM_NFKD = 3,
       
   134   /** Canonical decomposition followed by canonical composition. @stable ICU 2.0 */
       
   135   UNORM_NFC = 4,
       
   136   /** Default normalization. @stable ICU 2.0 */
       
   137   UNORM_DEFAULT = UNORM_NFC, 
       
   138   /** Compatibility decomposition followed by canonical composition. @stable ICU 2.0 */
       
   139   UNORM_NFKC =5,
       
   140   /** "Fast C or D" form. @stable ICU 2.0 */
       
   141   UNORM_FCD = 6,
       
   142 
       
   143   /** One more than the highest normalization mode constant. @stable ICU 2.0 */
       
   144   UNORM_MODE_COUNT
       
   145 } UNormalizationMode;
       
   146 
       
   147 /**
       
   148  * Constants for options flags for normalization.
       
   149  * Use 0 for default options,
       
   150  * including normalization according to the Unicode version
       
   151  * that is currently supported by ICU (see u_getUnicodeVersion).
       
   152  * @stable ICU 2.6
       
   153  */
       
   154 enum {
       
   155     /**
       
   156      * Options bit set value to select Unicode 3.2 normalization
       
   157      * (except NormalizationCorrections).
       
   158      * At most one Unicode version can be selected at a time.
       
   159      * @stable ICU 2.6
       
   160      */
       
   161     UNORM_UNICODE_3_2=0x20
       
   162 };
       
   163 
       
   164 /**
       
   165  * Lowest-order bit number of unorm_compare() options bits corresponding to
       
   166  * normalization options bits.
       
   167  *
       
   168  * The options parameter for unorm_compare() uses most bits for
       
   169  * itself and for various comparison and folding flags.
       
   170  * The most significant bits, however, are shifted down and passed on
       
   171  * to the normalization implementation.
       
   172  * (That is, from unorm_compare(..., options, ...),
       
   173  * options>>UNORM_COMPARE_NORM_OPTIONS_SHIFT will be passed on to the
       
   174  * internal normalization functions.)
       
   175  *
       
   176  * @see unorm_compare
       
   177  * @stable ICU 2.6
       
   178  */
       
   179 #define UNORM_COMPARE_NORM_OPTIONS_SHIFT 20
       
   180 
       
   181 /**
       
   182  * Normalize a string.
       
   183  * The string will be normalized according the specified normalization mode
       
   184  * and options.
       
   185  *
       
   186  * @param source The string to normalize.
       
   187  * @param sourceLength The length of source, or -1 if NUL-terminated.
       
   188  * @param mode The normalization mode; one of UNORM_NONE, 
       
   189  *             UNORM_NFD, UNORM_NFC, UNORM_NFKC, UNORM_NFKD, UNORM_DEFAULT.
       
   190  * @param options The normalization options, ORed together (0 for no options).
       
   191  * @param result A pointer to a buffer to receive the result string.
       
   192  *               The result string is NUL-terminated if possible.
       
   193  * @param resultLength The maximum size of result.
       
   194  * @param status A pointer to a UErrorCode to receive any errors.
       
   195  * @return The total buffer size needed; if greater than resultLength,
       
   196  *         the output was truncated, and the error code is set to U_BUFFER_OVERFLOW_ERROR.
       
   197  * @stable ICU 2.0
       
   198  */
       
   199 U_STABLE int32_t U_EXPORT2 
       
   200 unorm_normalize(const UChar *source, int32_t sourceLength,
       
   201                 UNormalizationMode mode, int32_t options,
       
   202                 UChar *result, int32_t resultLength,
       
   203                 UErrorCode *status);
       
   204 #endif
       
   205 /**
       
   206  * Result values for unorm_quickCheck().
       
   207  * For details see Unicode Technical Report 15.
       
   208  * @stable ICU 2.0
       
   209  */
       
   210 typedef enum UNormalizationCheckResult {
       
   211   /** 
       
   212    * Indicates that string is not in the normalized format
       
   213    */
       
   214   UNORM_NO,
       
   215   /** 
       
   216    * Indicates that string is in the normalized format
       
   217    */
       
   218   UNORM_YES,
       
   219   /** 
       
   220    * Indicates that string cannot be determined if it is in the normalized 
       
   221    * format without further thorough checks.
       
   222    */
       
   223   UNORM_MAYBE
       
   224 } UNormalizationCheckResult;
       
   225 #if !UCONFIG_NO_NORMALIZATION
       
   226 /**
       
   227  * Performing quick check on a string, to quickly determine if the string is 
       
   228  * in a particular normalization format.
       
   229  * Three types of result can be returned UNORM_YES, UNORM_NO or
       
   230  * UNORM_MAYBE. Result UNORM_YES indicates that the argument
       
   231  * string is in the desired normalized format, UNORM_NO determines that
       
   232  * argument string is not in the desired normalized format. A 
       
   233  * UNORM_MAYBE result indicates that a more thorough check is required, 
       
   234  * the user may have to put the string in its normalized form and compare the 
       
   235  * results.
       
   236  *
       
   237  * @param source       string for determining if it is in a normalized format
       
   238  * @param sourcelength length of source to test, or -1 if NUL-terminated
       
   239  * @param mode         which normalization form to test for
       
   240  * @param status       a pointer to a UErrorCode to receive any errors
       
   241  * @return UNORM_YES, UNORM_NO or UNORM_MAYBE
       
   242  *
       
   243  * @see unorm_isNormalized
       
   244  * @stable ICU 2.0
       
   245  */
       
   246 U_STABLE UNormalizationCheckResult U_EXPORT2
       
   247 unorm_quickCheck(const UChar *source, int32_t sourcelength,
       
   248                  UNormalizationMode mode,
       
   249                  UErrorCode *status);
       
   250 
       
   251 /**
       
   252  * Performing quick check on a string; same as unorm_quickCheck but
       
   253  * takes an extra options parameter like most normalization functions.
       
   254  *
       
   255  * @param src        String that is to be tested if it is in a normalization format.
       
   256  * @param srcLength  Length of source to test, or -1 if NUL-terminated.
       
   257  * @param mode       Which normalization form to test for.
       
   258  * @param options    The normalization options, ORed together (0 for no options).
       
   259  * @param pErrorCode ICU error code in/out parameter.
       
   260  *                   Must fulfill U_SUCCESS before the function call.
       
   261  * @return UNORM_YES, UNORM_NO or UNORM_MAYBE
       
   262  *
       
   263  * @see unorm_quickCheck
       
   264  * @see unorm_isNormalized
       
   265  * @stable ICU 2.6
       
   266  */
       
   267 U_STABLE UNormalizationCheckResult U_EXPORT2
       
   268 unorm_quickCheckWithOptions(const UChar *src, int32_t srcLength, 
       
   269                             UNormalizationMode mode, int32_t options,
       
   270                             UErrorCode *pErrorCode);
       
   271 
       
   272 /**
       
   273  * Test if a string is in a given normalization form.
       
   274  * This is semantically equivalent to source.equals(normalize(source, mode)) .
       
   275  *
       
   276  * Unlike unorm_quickCheck(), this function returns a definitive result,
       
   277  * never a "maybe".
       
   278  * For NFD, NFKD, and FCD, both functions work exactly the same.
       
   279  * For NFC and NFKC where quickCheck may return "maybe", this function will
       
   280  * perform further tests to arrive at a TRUE/FALSE result.
       
   281  *
       
   282  * @param src        String that is to be tested if it is in a normalization format.
       
   283  * @param srcLength  Length of source to test, or -1 if NUL-terminated.
       
   284  * @param mode       Which normalization form to test for.
       
   285  * @param pErrorCode ICU error code in/out parameter.
       
   286  *                   Must fulfill U_SUCCESS before the function call.
       
   287  * @return Boolean value indicating whether the source string is in the
       
   288  *         "mode" normalization form.
       
   289  *
       
   290  * @see unorm_quickCheck
       
   291  * @stable ICU 2.2
       
   292  */
       
   293 U_STABLE UBool U_EXPORT2
       
   294 unorm_isNormalized(const UChar *src, int32_t srcLength,
       
   295                    UNormalizationMode mode,
       
   296                    UErrorCode *pErrorCode);
       
   297 
       
   298 /**
       
   299  * Test if a string is in a given normalization form; same as unorm_isNormalized but
       
   300  * takes an extra options parameter like most normalization functions.
       
   301  *
       
   302  * @param src        String that is to be tested if it is in a normalization format.
       
   303  * @param srcLength  Length of source to test, or -1 if NUL-terminated.
       
   304  * @param mode       Which normalization form to test for.
       
   305  * @param options    The normalization options, ORed together (0 for no options).
       
   306  * @param pErrorCode ICU error code in/out parameter.
       
   307  *                   Must fulfill U_SUCCESS before the function call.
       
   308  * @return Boolean value indicating whether the source string is in the
       
   309  *         "mode/options" normalization form.
       
   310  *
       
   311  * @see unorm_quickCheck
       
   312  * @see unorm_isNormalized
       
   313  * @stable ICU 2.6
       
   314  */
       
   315 U_STABLE UBool U_EXPORT2
       
   316 unorm_isNormalizedWithOptions(const UChar *src, int32_t srcLength,
       
   317                               UNormalizationMode mode, int32_t options,
       
   318                               UErrorCode *pErrorCode);
       
   319 
       
   320 /**
       
   321  * Iterative normalization forward.
       
   322  * This function (together with unorm_previous) is somewhat
       
   323  * similar to the C++ Normalizer class (see its non-static functions).
       
   324  *
       
   325  * Iterative normalization is useful when only a small portion of a longer
       
   326  * string/text needs to be processed.
       
   327  *
       
   328  * For example, the likelihood may be high that processing the first 10% of some
       
   329  * text will be sufficient to find certain data.
       
   330  * Another example: When one wants to concatenate two normalized strings and get a
       
   331  * normalized result, it is much more efficient to normalize just a small part of
       
   332  * the result around the concatenation place instead of re-normalizing everything.
       
   333  *
       
   334  * The input text is an instance of the C character iteration API UCharIterator.
       
   335  * It may wrap around a simple string, a CharacterIterator, a Replaceable, or any
       
   336  * other kind of text object.
       
   337  *
       
   338  * If a buffer overflow occurs, then the caller needs to reset the iterator to the
       
   339  * old index and call the function again with a larger buffer - if the caller cares
       
   340  * for the actual output.
       
   341  * Regardless of the output buffer, the iterator will always be moved to the next
       
   342  * normalization boundary.
       
   343  *
       
   344  * This function (like unorm_previous) serves two purposes:
       
   345  *
       
   346  * 1) To find the next boundary so that the normalization of the part of the text
       
   347  * from the current position to that boundary does not affect and is not affected
       
   348  * by the part of the text beyond that boundary.
       
   349  *
       
   350  * 2) To normalize the text up to the boundary.
       
   351  *
       
   352  * The second step is optional, per the doNormalize parameter.
       
   353  * It is omitted for operations like string concatenation, where the two adjacent
       
   354  * string ends need to be normalized together.
       
   355  * In such a case, the output buffer will just contain a copy of the text up to the
       
   356  * boundary.
       
   357  *
       
   358  * pNeededToNormalize is an output-only parameter. Its output value is only defined
       
   359  * if normalization was requested (doNormalize) and successful (especially, no
       
   360  * buffer overflow).
       
   361  * It is useful for operations like a normalizing transliterator, where one would
       
   362  * not want to replace a piece of text if it is not modified.
       
   363  *
       
   364  * If doNormalize==TRUE and pNeededToNormalize!=NULL then *pNeeded... is set TRUE
       
   365  * if the normalization was necessary.
       
   366  *
       
   367  * If doNormalize==FALSE then *pNeededToNormalize will be set to FALSE.
       
   368  *
       
   369  * If the buffer overflows, then *pNeededToNormalize will be undefined;
       
   370  * essentially, whenever U_FAILURE is true (like in buffer overflows), this result
       
   371  * will be undefined.
       
   372  *
       
   373  * @param src The input text in the form of a C character iterator.
       
   374  * @param dest The output buffer; can be NULL if destCapacity==0 for pure preflighting.
       
   375  * @param destCapacity The number of UChars that fit into dest.
       
   376  * @param mode The normalization mode.
       
   377  * @param options The normalization options, ORed together (0 for no options).
       
   378  * @param doNormalize Indicates if the source text up to the next boundary
       
   379  *                    is to be normalized (TRUE) or just copied (FALSE).
       
   380  * @param pNeededToNormalize Output flag indicating if the normalization resulted in
       
   381  *                           different text from the input.
       
   382  *                           Not defined if an error occurs including buffer overflow.
       
   383  *                           Always FALSE if !doNormalize.
       
   384  * @param pErrorCode ICU error code in/out parameter.
       
   385  *                   Must fulfill U_SUCCESS before the function call.
       
   386  * @return Length of output (number of UChars) when successful or buffer overflow.
       
   387  *
       
   388  * @see unorm_previous
       
   389  * @see unorm_normalize
       
   390  *
       
   391  * @stable ICU 2.1
       
   392  */
       
   393 U_STABLE int32_t U_EXPORT2
       
   394 unorm_next(UCharIterator *src,
       
   395            UChar *dest, int32_t destCapacity,
       
   396            UNormalizationMode mode, int32_t options,
       
   397            UBool doNormalize, UBool *pNeededToNormalize,
       
   398            UErrorCode *pErrorCode);
       
   399 
       
   400 /**
       
   401  * Iterative normalization backward.
       
   402  * This function (together with unorm_next) is somewhat
       
   403  * similar to the C++ Normalizer class (see its non-static functions).
       
   404  * For all details see unorm_next.
       
   405  *
       
   406  * @param src The input text in the form of a C character iterator.
       
   407  * @param dest The output buffer; can be NULL if destCapacity==0 for pure preflighting.
       
   408  * @param destCapacity The number of UChars that fit into dest.
       
   409  * @param mode The normalization mode.
       
   410  * @param options The normalization options, ORed together (0 for no options).
       
   411  * @param doNormalize Indicates if the source text up to the next boundary
       
   412  *                    is to be normalized (TRUE) or just copied (FALSE).
       
   413  * @param pNeededToNormalize Output flag indicating if the normalization resulted in
       
   414  *                           different text from the input.
       
   415  *                           Not defined if an error occurs including buffer overflow.
       
   416  *                           Always FALSE if !doNormalize.
       
   417  * @param pErrorCode ICU error code in/out parameter.
       
   418  *                   Must fulfill U_SUCCESS before the function call.
       
   419  * @return Length of output (number of UChars) when successful or buffer overflow.
       
   420  *
       
   421  * @see unorm_next
       
   422  * @see unorm_normalize
       
   423  *
       
   424  * @stable ICU 2.1
       
   425  */
       
   426 U_STABLE int32_t U_EXPORT2
       
   427 unorm_previous(UCharIterator *src,
       
   428                UChar *dest, int32_t destCapacity,
       
   429                UNormalizationMode mode, int32_t options,
       
   430                UBool doNormalize, UBool *pNeededToNormalize,
       
   431                UErrorCode *pErrorCode);
       
   432 
       
   433 /**
       
   434  * Concatenate normalized strings, making sure that the result is normalized as well.
       
   435  *
       
   436  * If both the left and the right strings are in
       
   437  * the normalization form according to "mode/options",
       
   438  * then the result will be
       
   439  *
       
   440  * \code
       
   441  *     dest=normalize(left+right, mode, options)
       
   442  * \endcode
       
   443  *
       
   444  * With the input strings already being normalized,
       
   445  * this function will use unorm_next() and unorm_previous()
       
   446  * to find the adjacent end pieces of the input strings.
       
   447  * Only the concatenation of these end pieces will be normalized and
       
   448  * then concatenated with the remaining parts of the input strings.
       
   449  *
       
   450  * It is allowed to have dest==left to avoid copying the entire left string.
       
   451  *
       
   452  * @param left Left source string, may be same as dest.
       
   453  * @param leftLength Length of left source string, or -1 if NUL-terminated.
       
   454  * @param right Right source string.
       
   455  * @param rightLength Length of right source string, or -1 if NUL-terminated.
       
   456  * @param dest The output buffer; can be NULL if destCapacity==0 for pure preflighting.
       
   457  * @param destCapacity The number of UChars that fit into dest.
       
   458  * @param mode The normalization mode.
       
   459  * @param options The normalization options, ORed together (0 for no options).
       
   460  * @param pErrorCode ICU error code in/out parameter.
       
   461  *                   Must fulfill U_SUCCESS before the function call.
       
   462  * @return Length of output (number of UChars) when successful or buffer overflow.
       
   463  *
       
   464  * @see unorm_normalize
       
   465  * @see unorm_next
       
   466  * @see unorm_previous
       
   467  *
       
   468  * @stable ICU 2.1
       
   469  */
       
   470 U_STABLE int32_t U_EXPORT2
       
   471 unorm_concatenate(const UChar *left, int32_t leftLength,
       
   472                   const UChar *right, int32_t rightLength,
       
   473                   UChar *dest, int32_t destCapacity,
       
   474                   UNormalizationMode mode, int32_t options,
       
   475                   UErrorCode *pErrorCode);
       
   476 
       
   477 /**
       
   478  * Option bit for unorm_compare:
       
   479  * Both input strings are assumed to fulfill FCD conditions.
       
   480  * @stable ICU 2.2
       
   481  */
       
   482 #define UNORM_INPUT_IS_FCD          0x20000
       
   483 
       
   484 /**
       
   485  * Option bit for unorm_compare:
       
   486  * Perform case-insensitive comparison.
       
   487  * @stable ICU 2.2
       
   488  */
       
   489 #define U_COMPARE_IGNORE_CASE       0x10000
       
   490 
       
   491 #ifndef U_COMPARE_CODE_POINT_ORDER
       
   492 /* see also unistr.h and ustring.h */
       
   493 /**
       
   494  * Option bit for u_strCaseCompare, u_strcasecmp, unorm_compare, etc:
       
   495  * Compare strings in code point order instead of code unit order.
       
   496  * @stable ICU 2.2
       
   497  */
       
   498 #define U_COMPARE_CODE_POINT_ORDER  0x8000
       
   499 #endif
       
   500 
       
   501 /**
       
   502  * Compare two strings for canonical equivalence.
       
   503  * Further options include case-insensitive comparison and
       
   504  * code point order (as opposed to code unit order).
       
   505  *
       
   506  * Canonical equivalence between two strings is defined as their normalized
       
   507  * forms (NFD or NFC) being identical.
       
   508  * This function compares strings incrementally instead of normalizing
       
   509  * (and optionally case-folding) both strings entirely,
       
   510  * improving performance significantly.
       
   511  *
       
   512  * Bulk normalization is only necessary if the strings do not fulfill the FCD
       
   513  * conditions. Only in this case, and only if the strings are relatively long,
       
   514  * is memory allocated temporarily.
       
   515  * For FCD strings and short non-FCD strings there is no memory allocation.
       
   516  *
       
   517  * Semantically, this is equivalent to
       
   518  *   strcmp[CodePointOrder](NFD(foldCase(NFD(s1))), NFD(foldCase(NFD(s2))))
       
   519  * where code point order and foldCase are all optional.
       
   520  *
       
   521  * UAX 21 2.5 Caseless Matching specifies that for a canonical caseless match
       
   522  * the case folding must be performed first, then the normalization.
       
   523  *
       
   524  * @param s1 First source string.
       
   525  * @param length1 Length of first source string, or -1 if NUL-terminated.
       
   526  *
       
   527  * @param s2 Second source string.
       
   528  * @param length2 Length of second source string, or -1 if NUL-terminated.
       
   529  *
       
   530  * @param options A bit set of options:
       
   531  *   - U_FOLD_CASE_DEFAULT or 0 is used for default options:
       
   532  *     Case-sensitive comparison in code unit order, and the input strings
       
   533  *     are quick-checked for FCD.
       
   534  *
       
   535  *   - UNORM_INPUT_IS_FCD
       
   536  *     Set if the caller knows that both s1 and s2 fulfill the FCD conditions.
       
   537  *     If not set, the function will quickCheck for FCD
       
   538  *     and normalize if necessary.
       
   539  *
       
   540  *   - U_COMPARE_CODE_POINT_ORDER
       
   541  *     Set to choose code point order instead of code unit order
       
   542  *     (see u_strCompare for details).
       
   543  *
       
   544  *   - U_COMPARE_IGNORE_CASE
       
   545  *     Set to compare strings case-insensitively using case folding,
       
   546  *     instead of case-sensitively.
       
   547  *     If set, then the following case folding options are used.
       
   548  *
       
   549  *   - Options as used with case-insensitive comparisons, currently:
       
   550  *
       
   551  *   - U_FOLD_CASE_EXCLUDE_SPECIAL_I
       
   552  *    (see u_strCaseCompare for details)
       
   553  *
       
   554  *   - regular normalization options shifted left by UNORM_COMPARE_NORM_OPTIONS_SHIFT
       
   555  *
       
   556  * @param pErrorCode ICU error code in/out parameter.
       
   557  *                   Must fulfill U_SUCCESS before the function call.
       
   558  * @return <0 or 0 or >0 as usual for string comparisons
       
   559  *
       
   560  * @see unorm_normalize
       
   561  * @see UNORM_FCD
       
   562  * @see u_strCompare
       
   563  * @see u_strCaseCompare
       
   564  *
       
   565  * @stable ICU 2.2
       
   566  */
       
   567 U_STABLE int32_t U_EXPORT2
       
   568 unorm_compare(const UChar *s1, int32_t length1,
       
   569               const UChar *s2, int32_t length2,
       
   570               uint32_t options,
       
   571               UErrorCode *pErrorCode);
       
   572 
       
   573 #endif /* #if !UCONFIG_NO_NORMALIZATION */
       
   574 
       
   575 #endif