/* ******************************************************************************* * Copyright (c) 1996-2010, International Business Machines Corporation * and others. All Rights Reserved. ******************************************************************************* * File unorm.h * * Created by: Vladimir Weinstein 12052000 * * Modification history : * * Date Name Description * 02/01/01 synwee Added normalization quickcheck enum and method. */ #ifndef UNORM_H #define UNORM_H #include "unicode/utypes.h" #if !UCONFIG_NO_NORMALIZATION #include "unicode/uiter.h" #include "unicode/unorm2.h" /** * \file * \brief C API: Unicode Normalization * * <h2>Unicode normalization API</h2> * * Note: This API has been replaced by the unorm2.h API and is only available * for backward compatibility. The functions here simply delegate to the * unorm2.h functions, for example unorm2_getInstance() and unorm2_normalize(). * There is one exception: The new API does not provide a replacement for unorm_compare(). * * <code>unorm_normalize</code> transforms Unicode text into an equivalent composed or * decomposed form, allowing for easier sorting and searching of text. * <code>unorm_normalize</code> supports the standard normalization forms described in * <a href="http://www.unicode.org/unicode/reports/tr15/" target="unicode"> * Unicode Standard Annex #15: Unicode Normalization Forms</a>. * * Characters with accents or other adornments can be encoded in * several different ways in Unicode. For example, take the character A-acute. * In Unicode, this can be encoded as a single character (the * "composed" form): * * \code * 00C1 LATIN CAPITAL LETTER A WITH ACUTE * \endcode * * or as two separate characters (the "decomposed" form): * * \code * 0041 LATIN CAPITAL LETTER A * 0301 COMBINING ACUTE ACCENT * \endcode * * To a user of your program, however, both of these sequences should be * treated as the same "user-level" character "A with acute accent". When you are searching or * comparing text, you must ensure that these two sequences are treated * equivalently. In addition, you must handle characters with more than one * accent. Sometimes the order of a character's combining accents is * significant, while in other cases accent sequences in different orders are * really equivalent. * * Similarly, the string "ffi" can be encoded as three separate letters: * * \code * 0066 LATIN SMALL LETTER F * 0066 LATIN SMALL LETTER F * 0069 LATIN SMALL LETTER I * \endcode * * or as the single character * * \code * FB03 LATIN SMALL LIGATURE FFI * \endcode * * The ffi ligature is not a distinct semantic character, and strictly speaking * it shouldn't be in Unicode at all, but it was included for compatibility * with existing character sets that already provided it. The Unicode standard * identifies such characters by giving them "compatibility" decompositions * into the corresponding semantic characters. When sorting and searching, you * will often want to use these mappings. * * <code>unorm_normalize</code> helps solve these problems by transforming text into the * canonical composed and decomposed forms as shown in the first example above. * In addition, you can have it perform compatibility decompositions so that * you can treat compatibility characters the same as their equivalents. * Finally, <code>unorm_normalize</code> rearranges accents into the proper canonical * order, so that you do not have to worry about accent rearrangement on your * own. * * Form FCD, "Fast C or D", is also designed for collation. * It allows to work on strings that are not necessarily normalized * with an algorithm (like in collation) that works under "canonical closure", i.e., it treats precomposed * characters and their decomposed equivalents the same. * * It is not a normalization form because it does not provide for uniqueness of representation. Multiple strings * may be canonically equivalent (their NFDs are identical) and may all conform to FCD without being identical * themselves. * * The form is defined such that the "raw decomposition", the recursive canonical decomposition of each character, * results in a string that is canonically ordered. This means that precomposed characters are allowed for as long * as their decompositions do not need canonical reordering. * * Its advantage for a process like collation is that all NFD and most NFC texts - and many unnormalized texts - * already conform to FCD and do not need to be normalized (NFD) for such a process. The FCD quick check will * return UNORM_YES for most strings in practice. * * unorm_normalize(UNORM_FCD) may be implemented with UNORM_NFD. * * For more details on FCD see the collation design document: * http://source.icu-project.org/repos/icu/icuhtml/trunk/design/collation/ICU_collation_design.htm * * ICU collation performs either NFD or FCD normalization automatically if normalization * is turned on for the collator object. * Beyond collation and string search, normalized strings may be useful for string equivalence comparisons, * transliteration/transcription, unique representations, etc. * * The W3C generally recommends to exchange texts in NFC. * Note also that most legacy character encodings use only precomposed forms and often do not * encode any combining marks by themselves. For conversion to such character encodings the * Unicode text needs to be normalized to NFC. * For more usage examples, see the Unicode Standard Annex. */ /** * Constants for normalization modes. * @stable ICU 2.0 */ typedef enum { /** No decomposition/composition. @stable ICU 2.0 */ UNORM_NONE = 1, /** Canonical decomposition. @stable ICU 2.0 */ UNORM_NFD = 2, /** Compatibility decomposition. @stable ICU 2.0 */ UNORM_NFKD = 3, /** Canonical decomposition followed by canonical composition. @stable ICU 2.0 */ UNORM_NFC = 4, /** Default normalization. @stable ICU 2.0 */ UNORM_DEFAULT = UNORM_NFC, /** Compatibility decomposition followed by canonical composition. @stable ICU 2.0 */ UNORM_NFKC =5, /** "Fast C or D" form. @stable ICU 2.0 */ UNORM_FCD = 6, /** One more than the highest normalization mode constant. @stable ICU 2.0 */ UNORM_MODE_COUNT } UNormalizationMode; /** * Constants for options flags for normalization. * Use 0 for default options, * including normalization according to the Unicode version * that is currently supported by ICU (see u_getUnicodeVersion). * @stable ICU 2.6 */ enum { /** * Options bit set value to select Unicode 3.2 normalization * (except NormalizationCorrections). * At most one Unicode version can be selected at a time. * @stable ICU 2.6 */ UNORM_UNICODE_3_2=0x20 }; /** * Lowest-order bit number of unorm_compare() options bits corresponding to * normalization options bits. * * The options parameter for unorm_compare() uses most bits for * itself and for various comparison and folding flags. * The most significant bits, however, are shifted down and passed on * to the normalization implementation. * (That is, from unorm_compare(..., options, ...), * options>>UNORM_COMPARE_NORM_OPTIONS_SHIFT will be passed on to the * internal normalization functions.) * * @see unorm_compare * @stable ICU 2.6 */ #define UNORM_COMPARE_NORM_OPTIONS_SHIFT 20 /** * Normalize a string. * The string will be normalized according the specified normalization mode * and options. * The source and result buffers must not be the same, nor overlap. * * @param source The string to normalize. * @param sourceLength The length of source, or -1 if NUL-terminated. * @param mode The normalization mode; one of UNORM_NONE, * UNORM_NFD, UNORM_NFC, UNORM_NFKC, UNORM_NFKD, UNORM_DEFAULT. * @param options The normalization options, ORed together (0 for no options). * @param result A pointer to a buffer to receive the result string. * The result string is NUL-terminated if possible. * @param resultLength The maximum size of result. * @param status A pointer to a UErrorCode to receive any errors. * @return The total buffer size needed; if greater than resultLength, * the output was truncated, and the error code is set to U_BUFFER_OVERFLOW_ERROR. * @stable ICU 2.0 */ U_STABLE int32_t U_EXPORT2 unorm_normalize(const UChar *source, int32_t sourceLength, UNormalizationMode mode, int32_t options, UChar *result, int32_t resultLength, UErrorCode *status); /** * Performing quick check on a string, to quickly determine if the string is * in a particular normalization format. * Three types of result can be returned UNORM_YES, UNORM_NO or * UNORM_MAYBE. Result UNORM_YES indicates that the argument * string is in the desired normalized format, UNORM_NO determines that * argument string is not in the desired normalized format. A * UNORM_MAYBE result indicates that a more thorough check is required, * the user may have to put the string in its normalized form and compare the * results. * * @param source string for determining if it is in a normalized format * @param sourcelength length of source to test, or -1 if NUL-terminated * @param mode which normalization form to test for * @param status a pointer to a UErrorCode to receive any errors * @return UNORM_YES, UNORM_NO or UNORM_MAYBE * * @see unorm_isNormalized * @stable ICU 2.0 */ U_STABLE UNormalizationCheckResult U_EXPORT2 unorm_quickCheck(const UChar *source, int32_t sourcelength, UNormalizationMode mode, UErrorCode *status); /** * Performing quick check on a string; same as unorm_quickCheck but * takes an extra options parameter like most normalization functions. * * @param src String that is to be tested if it is in a normalization format. * @param srcLength Length of source to test, or -1 if NUL-terminated. * @param mode Which normalization form to test for. * @param options The normalization options, ORed together (0 for no options). * @param pErrorCode ICU error code in/out parameter. * Must fulfill U_SUCCESS before the function call. * @return UNORM_YES, UNORM_NO or UNORM_MAYBE * * @see unorm_quickCheck * @see unorm_isNormalized * @stable ICU 2.6 */ U_STABLE UNormalizationCheckResult U_EXPORT2 unorm_quickCheckWithOptions(const UChar *src, int32_t srcLength, UNormalizationMode mode, int32_t options, UErrorCode *pErrorCode); /** * Test if a string is in a given normalization form. * This is semantically equivalent to source.equals(normalize(source, mode)) . * * Unlike unorm_quickCheck(), this function returns a definitive result, * never a "maybe". * For NFD, NFKD, and FCD, both functions work exactly the same. * For NFC and NFKC where quickCheck may return "maybe", this function will * perform further tests to arrive at a TRUE/FALSE result. * * @param src String that is to be tested if it is in a normalization format. * @param srcLength Length of source to test, or -1 if NUL-terminated. * @param mode Which normalization form to test for. * @param pErrorCode ICU error code in/out parameter. * Must fulfill U_SUCCESS before the function call. * @return Boolean value indicating whether the source string is in the * "mode" normalization form. * * @see unorm_quickCheck * @stable ICU 2.2 */ U_STABLE UBool U_EXPORT2 unorm_isNormalized(const UChar *src, int32_t srcLength, UNormalizationMode mode, UErrorCode *pErrorCode); /** * Test if a string is in a given normalization form; same as unorm_isNormalized but * takes an extra options parameter like most normalization functions. * * @param src String that is to be tested if it is in a normalization format. * @param srcLength Length of source to test, or -1 if NUL-terminated. * @param mode Which normalization form to test for. * @param options The normalization options, ORed together (0 for no options). * @param pErrorCode ICU error code in/out parameter. * Must fulfill U_SUCCESS before the function call. * @return Boolean value indicating whether the source string is in the * "mode/options" normalization form. * * @see unorm_quickCheck * @see unorm_isNormalized * @stable ICU 2.6 */ U_STABLE UBool U_EXPORT2 unorm_isNormalizedWithOptions(const UChar *src, int32_t srcLength, UNormalizationMode mode, int32_t options, UErrorCode *pErrorCode); /** * Iterative normalization forward. * This function (together with unorm_previous) is somewhat * similar to the C++ Normalizer class (see its non-static functions). * * Iterative normalization is useful when only a small portion of a longer * string/text needs to be processed. * * For example, the likelihood may be high that processing the first 10% of some * text will be sufficient to find certain data. * Another example: When one wants to concatenate two normalized strings and get a * normalized result, it is much more efficient to normalize just a small part of * the result around the concatenation place instead of re-normalizing everything. * * The input text is an instance of the C character iteration API UCharIterator. * It may wrap around a simple string, a CharacterIterator, a Replaceable, or any * other kind of text object. * * If a buffer overflow occurs, then the caller needs to reset the iterator to the * old index and call the function again with a larger buffer - if the caller cares * for the actual output. * Regardless of the output buffer, the iterator will always be moved to the next * normalization boundary. * * This function (like unorm_previous) serves two purposes: * * 1) To find the next boundary so that the normalization of the part of the text * from the current position to that boundary does not affect and is not affected * by the part of the text beyond that boundary. * * 2) To normalize the text up to the boundary. * * The second step is optional, per the doNormalize parameter. * It is omitted for operations like string concatenation, where the two adjacent * string ends need to be normalized together. * In such a case, the output buffer will just contain a copy of the text up to the * boundary. * * pNeededToNormalize is an output-only parameter. Its output value is only defined * if normalization was requested (doNormalize) and successful (especially, no * buffer overflow). * It is useful for operations like a normalizing transliterator, where one would * not want to replace a piece of text if it is not modified. * * If doNormalize==TRUE and pNeededToNormalize!=NULL then *pNeeded... is set TRUE * if the normalization was necessary. * * If doNormalize==FALSE then *pNeededToNormalize will be set to FALSE. * * If the buffer overflows, then *pNeededToNormalize will be undefined; * essentially, whenever U_FAILURE is true (like in buffer overflows), this result * will be undefined. * * @param src The input text in the form of a C character iterator. * @param dest The output buffer; can be NULL if destCapacity==0 for pure preflighting. * @param destCapacity The number of UChars that fit into dest. * @param mode The normalization mode. * @param options The normalization options, ORed together (0 for no options). * @param doNormalize Indicates if the source text up to the next boundary * is to be normalized (TRUE) or just copied (FALSE). * @param pNeededToNormalize Output flag indicating if the normalization resulted in * different text from the input. * Not defined if an error occurs including buffer overflow. * Always FALSE if !doNormalize. * @param pErrorCode ICU error code in/out parameter. * Must fulfill U_SUCCESS before the function call. * @return Length of output (number of UChars) when successful or buffer overflow. * * @see unorm_previous * @see unorm_normalize * * @stable ICU 2.1 */ U_STABLE int32_t U_EXPORT2 unorm_next(UCharIterator *src, UChar *dest, int32_t destCapacity, UNormalizationMode mode, int32_t options, UBool doNormalize, UBool *pNeededToNormalize, UErrorCode *pErrorCode); /** * Iterative normalization backward. * This function (together with unorm_next) is somewhat * similar to the C++ Normalizer class (see its non-static functions). * For all details see unorm_next. * * @param src The input text in the form of a C character iterator. * @param dest The output buffer; can be NULL if destCapacity==0 for pure preflighting. * @param destCapacity The number of UChars that fit into dest. * @param mode The normalization mode. * @param options The normalization options, ORed together (0 for no options). * @param doNormalize Indicates if the source text up to the next boundary * is to be normalized (TRUE) or just copied (FALSE). * @param pNeededToNormalize Output flag indicating if the normalization resulted in * different text from the input. * Not defined if an error occurs including buffer overflow. * Always FALSE if !doNormalize. * @param pErrorCode ICU error code in/out parameter. * Must fulfill U_SUCCESS before the function call. * @return Length of output (number of UChars) when successful or buffer overflow. * * @see unorm_next * @see unorm_normalize * * @stable ICU 2.1 */ U_STABLE int32_t U_EXPORT2 unorm_previous(UCharIterator *src, UChar *dest, int32_t destCapacity, UNormalizationMode mode, int32_t options, UBool doNormalize, UBool *pNeededToNormalize, UErrorCode *pErrorCode); /** * Concatenate normalized strings, making sure that the result is normalized as well. * * If both the left and the right strings are in * the normalization form according to "mode/options", * then the result will be * * \code * dest=normalize(left+right, mode, options) * \endcode * * With the input strings already being normalized, * this function will use unorm_next() and unorm_previous() * to find the adjacent end pieces of the input strings. * Only the concatenation of these end pieces will be normalized and * then concatenated with the remaining parts of the input strings. * * It is allowed to have dest==left to avoid copying the entire left string. * * @param left Left source string, may be same as dest. * @param leftLength Length of left source string, or -1 if NUL-terminated. * @param right Right source string. Must not be the same as dest, nor overlap. * @param rightLength Length of right source string, or -1 if NUL-terminated. * @param dest The output buffer; can be NULL if destCapacity==0 for pure preflighting. * @param destCapacity The number of UChars that fit into dest. * @param mode The normalization mode. * @param options The normalization options, ORed together (0 for no options). * @param pErrorCode ICU error code in/out parameter. * Must fulfill U_SUCCESS before the function call. * @return Length of output (number of UChars) when successful or buffer overflow. * * @see unorm_normalize * @see unorm_next * @see unorm_previous * * @stable ICU 2.1 */ U_STABLE int32_t U_EXPORT2 unorm_concatenate(const UChar *left, int32_t leftLength, const UChar *right, int32_t rightLength, UChar *dest, int32_t destCapacity, UNormalizationMode mode, int32_t options, UErrorCode *pErrorCode); /** * Option bit for unorm_compare: * Both input strings are assumed to fulfill FCD conditions. * @stable ICU 2.2 */ #define UNORM_INPUT_IS_FCD 0x20000 /** * Option bit for unorm_compare: * Perform case-insensitive comparison. * @stable ICU 2.2 */ #define U_COMPARE_IGNORE_CASE 0x10000 #ifndef U_COMPARE_CODE_POINT_ORDER /* see also unistr.h and ustring.h */ /** * Option bit for u_strCaseCompare, u_strcasecmp, unorm_compare, etc: * Compare strings in code point order instead of code unit order. * @stable ICU 2.2 */ #define U_COMPARE_CODE_POINT_ORDER 0x8000 #endif /** * Compare two strings for canonical equivalence. * Further options include case-insensitive comparison and * code point order (as opposed to code unit order). * * Canonical equivalence between two strings is defined as their normalized * forms (NFD or NFC) being identical. * This function compares strings incrementally instead of normalizing * (and optionally case-folding) both strings entirely, * improving performance significantly. * * Bulk normalization is only necessary if the strings do not fulfill the FCD * conditions. Only in this case, and only if the strings are relatively long, * is memory allocated temporarily. * For FCD strings and short non-FCD strings there is no memory allocation. * * Semantically, this is equivalent to * strcmp[CodePointOrder](NFD(foldCase(NFD(s1))), NFD(foldCase(NFD(s2)))) * where code point order and foldCase are all optional. * * UAX 21 2.5 Caseless Matching specifies that for a canonical caseless match * the case folding must be performed first, then the normalization. * * @param s1 First source string. * @param length1 Length of first source string, or -1 if NUL-terminated. * * @param s2 Second source string. * @param length2 Length of second source string, or -1 if NUL-terminated. * * @param options A bit set of options: * - U_FOLD_CASE_DEFAULT or 0 is used for default options: * Case-sensitive comparison in code unit order, and the input strings * are quick-checked for FCD. * * - UNORM_INPUT_IS_FCD * Set if the caller knows that both s1 and s2 fulfill the FCD conditions. * If not set, the function will quickCheck for FCD * and normalize if necessary. * * - U_COMPARE_CODE_POINT_ORDER * Set to choose code point order instead of code unit order * (see u_strCompare for details). * * - U_COMPARE_IGNORE_CASE * Set to compare strings case-insensitively using case folding, * instead of case-sensitively. * If set, then the following case folding options are used. * * - Options as used with case-insensitive comparisons, currently: * * - U_FOLD_CASE_EXCLUDE_SPECIAL_I * (see u_strCaseCompare for details) * * - regular normalization options shifted left by UNORM_COMPARE_NORM_OPTIONS_SHIFT * * @param pErrorCode ICU error code in/out parameter. * Must fulfill U_SUCCESS before the function call. * @return <0 or 0 or >0 as usual for string comparisons * * @see unorm_normalize * @see UNORM_FCD * @see u_strCompare * @see u_strCaseCompare * * @stable ICU 2.2 */ U_STABLE int32_t U_EXPORT2 unorm_compare(const UChar *s1, int32_t length1, const UChar *s2, int32_t length2, uint32_t options, UErrorCode *pErrorCode); #endif /* #if !UCONFIG_NO_NORMALIZATION */ #endif