/usr/include/unicode/ucoleitr.h (10056B)
* . "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').
*
* And in German phonebook collation,
* * . "*b"-> the first key is key('a'), the second key is key('e'), and * . the third key is key('b'). *
Example of the iterator usage: (without error checking) *
* . 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);
* . }
*
* * 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 int32_t. * * @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