1 /* 2 ******************************************************************************* 3 * Copyright (C) 2001-2004, International Business Machines 4 * Corporation and others. All Rights Reserved. 5 ******************************************************************************* 6 * 7 * File ucoleitr.cpp 8 * 9 * Modification History: 10 * 11 * Date Name Description 12 * 02/15/2001 synwee Modified all methods to process its own function 13 * instead of calling the equivalent c++ api (coleitr.h) 14 *******************************************************************************/ 15 16 #ifndef UCOLEITR_H 17 #define UCOLEITR_H 18 19 #include "unicode/utypes.h" 20 21 #if !UCONFIG_NO_COLLATION 22 23 /** 24 * This indicates an error has occured during processing or if no more CEs is 25 * to be returned. 26 * @stable ICU 2.0 27 */ 28 #define UCOL_NULLORDER ((int32_t)0xFFFFFFFF) 29 30 #include "unicode/ucol.h" 31 32 /** 33 * The UCollationElements struct. 34 * For usage in C programs. 35 * @stable ICU 2.0 36 */ 37 typedef struct UCollationElements UCollationElements; 38 39 /** 40 * \file 41 * \brief C API: UCollationElements 42 * 43 * The UCollationElements API is used as an iterator to walk through each 44 * character of an international string. Use the iterator to return the 45 * ordering priority of the positioned character. The ordering priority of a 46 * character, which we refer to as a key, defines how a character is collated 47 * in the given collation object. 48 * For example, consider the following in Spanish: 49 * <pre> 50 * . "ca" -> the first key is key('c') and second key is key('a'). 51 * . "cha" -> the first key is key('ch') and second key is key('a'). 52 * </pre> 53 * And in German, 54 * <pre> 55 * . "<ae ligature>b"-> the first key is key('a'), the second key is key('e'), and 56 * . the third key is key('b'). 57 * </pre> 58 * <p>Example of the iterator usage: (without error checking) 59 * <pre> 60 * . void CollationElementIterator_Example() 61 * . { 62 * . UChar *s; 63 * . t_int32 order, primaryOrder; 64 * . UCollationElements *c; 65 * . UCollatorOld *coll; 66 * . UErrorCode success = U_ZERO_ERROR; 67 * . s=(UChar*)malloc(sizeof(UChar) * (strlen("This is a test")+1) ); 68 * . u_uastrcpy(s, "This is a test"); 69 * . coll = ucol_open(NULL, &success); 70 * . c = ucol_openElements(coll, str, u_strlen(str), &status); 71 * . order = ucol_next(c, &success); 72 * . ucol_reset(c); 73 * . order = ucol_prev(c, &success); 74 * . free(s); 75 * . ucol_close(coll); 76 * . ucol_closeElements(c); 77 * . } 78 * </pre> 79 * <p> 80 * ucol_next() returns the collation order of the next. 81 * ucol_prev() returns the collation order of the previous character. 82 * The Collation Element Iterator moves only in one direction between calls to 83 * ucol_reset. That is, ucol_next() and ucol_prev can not be inter-used. 84 * Whenever ucol_prev is to be called after ucol_next() or vice versa, 85 * ucol_reset has to be called first to reset the status, shifting pointers to 86 * either the end or the start of the string. Hence at the next call of 87 * ucol_prev or ucol_next, the first or last collation order will be returned. 88 * If a change of direction is done without a ucol_reset, the result is 89 * undefined. 90 * The result of a forward iterate (ucol_next) and reversed result of the 91 * backward iterate (ucol_prev) on the same string are equivalent, if 92 * collation orders with the value UCOL_IGNORABLE are ignored. 93 * Character based on the comparison level of the collator. A collation order 94 * consists of primary order, secondary order and tertiary order. The data 95 * type of the collation order is <strong>t_int32</strong>. 96 * 97 * @see UCollator 98 */ 99 100 /** 101 * Open the collation elements for a string. 102 * 103 * @param coll The collator containing the desired collation rules. 104 * @param text The text to iterate over. 105 * @param textLength The number of characters in text, or -1 if null-terminated 106 * @param status A pointer to an UErrorCode to receive any errors. 107 * @return a struct containing collation element information 108 * @stable ICU 2.0 109 */ 110 U_STABLE UCollationElements* U_EXPORT2 111 ucol_openElements(const UCollator *coll, 112 const UChar *text, 113 int32_t textLength, 114 UErrorCode *status); 115 116 /** 117 * get a hash code for a key... Not very useful! 118 * @param key the given key. 119 * @param length the size of the key array. 120 * @return the hash code. 121 * @stable ICU 2.0 122 */ 123 U_STABLE int32_t U_EXPORT2 124 ucol_keyHashCode(const uint8_t* key, int32_t length); 125 126 /** 127 * Close a UCollationElements. 128 * Once closed, a UCollationElements may no longer be used. 129 * @param elems The UCollationElements to close. 130 * @stable ICU 2.0 131 */ 132 U_STABLE void U_EXPORT2 133 ucol_closeElements(UCollationElements *elems); 134 135 /** 136 * Reset the collation elements to their initial state. 137 * This will move the 'cursor' to the beginning of the text. 138 * Property settings for collation will be reset to the current status. 139 * @param elems The UCollationElements to reset. 140 * @see ucol_next 141 * @see ucol_previous 142 * @stable ICU 2.0 143 */ 144 U_STABLE void U_EXPORT2 145 ucol_reset(UCollationElements *elems); 146 147 /** 148 * Get the ordering priority of the next collation element in the text. 149 * A single character may contain more than one collation element. 150 * @param elems The UCollationElements containing the text. 151 * @param status A pointer to an UErrorCode to receive any errors. 152 * @return The next collation elements ordering, otherwise returns NULLORDER 153 * if an error has occured or if the end of string has been reached 154 * @stable ICU 2.0 155 */ 156 U_STABLE int32_t U_EXPORT2 157 ucol_next(UCollationElements *elems, UErrorCode *status); 158 159 /** 160 * Get the ordering priority of the previous collation element in the text. 161 * A single character may contain more than one collation element. 162 * Note that internally a stack is used to store buffered collation elements. 163 * It is very rare that the stack will overflow, however if such a case is 164 * encountered, the problem can be solved by increasing the size 165 * UCOL_EXPAND_CE_BUFFER_SIZE in ucol_imp.h. 166 * @param elems The UCollationElements containing the text. 167 * @param status A pointer to an UErrorCode to receive any errors. Noteably 168 * a U_BUFFER_OVERFLOW_ERROR is returned if the internal stack 169 * buffer has been exhausted. 170 * @return The previous collation elements ordering, otherwise returns 171 * NULLORDER if an error has occured or if the start of string has 172 * been reached. 173 * @stable ICU 2.0 174 */ 175 U_STABLE int32_t U_EXPORT2 176 ucol_previous(UCollationElements *elems, UErrorCode *status); 177 178 /** 179 * Get the maximum length of any expansion sequences that end with the 180 * specified comparison order. 181 * This is useful for .... ? 182 * @param elems The UCollationElements containing the text. 183 * @param order A collation order returned by previous or next. 184 * @return maximum size of the expansion sequences ending with the collation 185 * element or 1 if collation element does not occur at the end of any 186 * expansion sequence 187 * @stable ICU 2.0 188 */ 189 U_STABLE int32_t U_EXPORT2 190 ucol_getMaxExpansion(const UCollationElements *elems, int32_t order); 191 192 /** 193 * Set the text containing the collation elements. 194 * Property settings for collation will remain the same. 195 * In order to reset the iterator to the current collation property settings, 196 * the API reset() has to be called. 197 * @param elems The UCollationElements to set. 198 * @param text The source text containing the collation elements. 199 * @param textLength The length of text, or -1 if null-terminated. 200 * @param status A pointer to an UErrorCode to receive any errors. 201 * @see ucol_getText 202 * @stable ICU 2.0 203 */ 204 U_STABLE void U_EXPORT2 205 ucol_setText( UCollationElements *elems, 206 const UChar *text, 207 int32_t textLength, 208 UErrorCode *status); 209 210 /** 211 * Get the offset of the current source character. 212 * This is an offset into the text of the character containing the current 213 * collation elements. 214 * @param elems The UCollationElements to query. 215 * @return The offset of the current source character. 216 * @see ucol_setOffset 217 * @stable ICU 2.0 218 */ 219 U_STABLE int32_t U_EXPORT2 220 ucol_getOffset(const UCollationElements *elems); 221 222 /** 223 * Set the offset of the current source character. 224 * This is an offset into the text of the character to be processed. 225 * Property settings for collation will remain the same. 226 * In order to reset the iterator to the current collation property settings, 227 * the API reset() has to be called. 228 * @param elems The UCollationElements to set. 229 * @param offset The desired character offset. 230 * @param status A pointer to an UErrorCode to receive any errors. 231 * @see ucol_getOffset 232 * @stable ICU 2.0 233 */ 234 U_STABLE void U_EXPORT2 235 ucol_setOffset(UCollationElements *elems, 236 int32_t offset, 237 UErrorCode *status); 238 239 /** 240 * Get the primary order of a collation order. 241 * @param order the collation order 242 * @return the primary order of a collation order. 243 * @stable ICU 2.6 244 */ 245 U_STABLE int32_t U_EXPORT2 246 ucol_primaryOrder (int32_t order); 247 248 /** 249 * Get the secondary order of a collation order. 250 * @param order the collation order 251 * @return the secondary order of a collation order. 252 * @stable ICU 2.6 253 */ 254 U_STABLE int32_t U_EXPORT2 255 ucol_secondaryOrder (int32_t order); 256 257 /** 258 * Get the tertiary order of a collation order. 259 * @param order the collation order 260 * @return the tertiary order of a collation order. 261 * @stable ICU 2.6 262 */ 263 U_STABLE int32_t U_EXPORT2 264 ucol_tertiaryOrder (int32_t order); 265 266 #endif /* #if !UCONFIG_NO_COLLATION */ 267 268 #endif 269