// © 2016 and later: Unicode, Inc. and others. // License & terms of use: http://www.unicode.org/copyright.html /* ******************************************************************************* * Copyright (C) 2001-2014, International Business Machines * Corporation and others. All Rights Reserved. ******************************************************************************* * * File ucoleitr.h * * Modification History: * * Date Name Description * 02/15/2001 synwee Modified all methods to process its own function * instead of calling the equivalent c++ api (coleitr.h) *******************************************************************************/ #ifndef UCOLEITR_H #define UCOLEITR_H #include "unicode/utypes.h" #if !UCONFIG_NO_COLLATION /** * This indicates an error has occurred during processing or if no more CEs is * to be returned. * @stable ICU 2.0 */ #define UCOL_NULLORDER … #include "unicode/ucol.h" /** * The UCollationElements struct. * For usage in C programs. * @stable ICU 2.0 */ UCollationElements; /** * \file * \brief C API: UCollationElements * * The UCollationElements API is used as an iterator to walk through each * character of an international string. Use the iterator to return the * ordering priority of the positioned character. The ordering priority of a * character, which we refer to as a key, defines how a character is collated * in the given collation object. * For example, consider the following in Slovak and in traditional Spanish collation: * <pre> * . "ca" -> the first key is key('c') and second key is key('a'). * . "cha" -> the first key is key('ch') and second key is key('a'). * </pre> * And in German phonebook collation, * <pre> * . "<ae ligature>b"-> the first key is key('a'), the second key is key('e'), and * . the third key is key('b'). * </pre> * <p>Example of the iterator usage: (without error checking) * <pre> * . void CollationElementIterator_Example() * . { * . UChar *s; * . t_int32 order, primaryOrder; * . UCollationElements *c; * . UCollatorOld *coll; * . UErrorCode success = U_ZERO_ERROR; * . str=(UChar*)malloc(sizeof(UChar) * (strlen("This is a test")+1) ); * . u_uastrcpy(str, "This is a test"); * . coll = ucol_open(NULL, &success); * . c = ucol_openElements(coll, str, u_strlen(str), &status); * . order = ucol_next(c, &success); * . ucol_reset(c); * . order = ucol_prev(c, &success); * . free(str); * . ucol_close(coll); * . ucol_closeElements(c); * . } * </pre> * <p> * ucol_next() returns the collation order of the next. * ucol_prev() returns the collation order of the previous character. * The Collation Element Iterator moves only in one direction between calls to * ucol_reset. That is, ucol_next() and ucol_prev can not be inter-used. * Whenever ucol_prev is to be called after ucol_next() or vice versa, * ucol_reset has to be called first to reset the status, shifting pointers to * either the end or the start of the string. Hence at the next call of * ucol_prev or ucol_next, the first or last collation order will be returned. * If a change of direction is done without a ucol_reset, the result is * undefined. * The result of a forward iterate (ucol_next) and reversed result of the * backward iterate (ucol_prev) on the same string are equivalent, if * collation orders with the value 0 are ignored. * Character based on the comparison level of the collator. A collation order * consists of primary order, secondary order and tertiary order. The data * type of the collation order is <strong>int32_t</strong>. * * @see UCollator */ /** * Open the collation elements for a string. * * The UCollationElements retains a pointer to the supplied text. * The caller must not modify or delete the text while the UCollationElements * object is used to iterate over this text. * * @param coll The collator containing the desired collation rules. * @param text The text to iterate over. * @param textLength The number of characters in text, or -1 if null-terminated * @param status A pointer to a UErrorCode to receive any errors. * @return a struct containing collation element information * @stable ICU 2.0 */ U_CAPI UCollationElements* U_EXPORT2 ucol_openElements(const UCollator *coll, const UChar *text, int32_t textLength, UErrorCode *status); /** * get a hash code for a key... Not very useful! * @param key the given key. * @param length the size of the key array. * @return the hash code. * @stable ICU 2.0 */ U_CAPI int32_t U_EXPORT2 ucol_keyHashCode(const uint8_t* key, int32_t length); /** * Close a UCollationElements. * Once closed, a UCollationElements may no longer be used. * @param elems The UCollationElements to close. * @stable ICU 2.0 */ U_CAPI void U_EXPORT2 ucol_closeElements(UCollationElements *elems); /** * Reset the collation elements to their initial state. * This will move the 'cursor' to the beginning of the text. * Property settings for collation will be reset to the current status. * @param elems The UCollationElements to reset. * @see ucol_next * @see ucol_previous * @stable ICU 2.0 */ U_CAPI void U_EXPORT2 ucol_reset(UCollationElements *elems); /** * Get the ordering priority of the next collation element in the text. * A single character may contain more than one collation element. * @param elems The UCollationElements containing the text. * @param status A pointer to a UErrorCode to receive any errors. * @return The next collation elements ordering, otherwise returns UCOL_NULLORDER * if an error has occurred or if the end of string has been reached * @stable ICU 2.0 */ U_CAPI int32_t U_EXPORT2 ucol_next(UCollationElements *elems, UErrorCode *status); /** * Get the ordering priority of the previous collation element in the text. * A single character may contain more than one collation element. * Note that internally a stack is used to store buffered collation elements. * @param elems The UCollationElements containing the text. * @param status A pointer to a UErrorCode to receive any errors. Notably * a U_BUFFER_OVERFLOW_ERROR is returned if the internal stack * buffer has been exhausted. * @return The previous collation elements ordering, otherwise returns * UCOL_NULLORDER if an error has occurred or if the start of string has * been reached. * @stable ICU 2.0 */ U_CAPI int32_t U_EXPORT2 ucol_previous(UCollationElements *elems, UErrorCode *status); /** * Get the maximum length of any expansion sequences that end with the * specified comparison order. * This is useful for .... ? * @param elems The UCollationElements containing the text. * @param order A collation order returned by previous or next. * @return maximum size of the expansion sequences ending with the collation * element or 1 if collation element does not occur at the end of any * expansion sequence * @stable ICU 2.0 */ U_CAPI int32_t U_EXPORT2 ucol_getMaxExpansion(const UCollationElements *elems, int32_t order); /** * Set the text containing the collation elements. * Property settings for collation will remain the same. * In order to reset the iterator to the current collation property settings, * the API reset() has to be called. * * The UCollationElements retains a pointer to the supplied text. * The caller must not modify or delete the text while the UCollationElements * object is used to iterate over this text. * * @param elems The UCollationElements to set. * @param text The source text containing the collation elements. * @param textLength The length of text, or -1 if null-terminated. * @param status A pointer to a UErrorCode to receive any errors. * @see ucol_getText * @stable ICU 2.0 */ U_CAPI void U_EXPORT2 ucol_setText( UCollationElements *elems, const UChar *text, int32_t textLength, UErrorCode *status); /** * Get the offset of the current source character. * This is an offset into the text of the character containing the current * collation elements. * @param elems The UCollationElements to query. * @return The offset of the current source character. * @see ucol_setOffset * @stable ICU 2.0 */ U_CAPI int32_t U_EXPORT2 ucol_getOffset(const UCollationElements *elems); /** * Set the offset of the current source character. * This is an offset into the text of the character to be processed. * Property settings for collation will remain the same. * In order to reset the iterator to the current collation property settings, * the API reset() has to be called. * @param elems The UCollationElements to set. * @param offset The desired character offset. * @param status A pointer to a UErrorCode to receive any errors. * @see ucol_getOffset * @stable ICU 2.0 */ U_CAPI void U_EXPORT2 ucol_setOffset(UCollationElements *elems, int32_t offset, UErrorCode *status); /** * Get the primary order of a collation order. * @param order the collation order * @return the primary order of a collation order. * @stable ICU 2.6 */ U_CAPI int32_t U_EXPORT2 ucol_primaryOrder (int32_t order); /** * Get the secondary order of a collation order. * @param order the collation order * @return the secondary order of a collation order. * @stable ICU 2.6 */ U_CAPI int32_t U_EXPORT2 ucol_secondaryOrder (int32_t order); /** * Get the tertiary order of a collation order. * @param order the collation order * @return the tertiary order of a collation order. * @stable ICU 2.6 */ U_CAPI int32_t U_EXPORT2 ucol_tertiaryOrder (int32_t order); #endif /* #if !UCONFIG_NO_COLLATION */ #endif
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