1 // Copyright (C) 2016 and later: Unicode, Inc. and others. 2 // License & terms of use: http://www.unicode.org/copyright.html 3 /******************************************************************** 4 * COPYRIGHT: 5 * Copyright (c) 1997-2011, International Business Machines Corporation and 6 * others. All Rights Reserved. 7 * Copyright (C) 2010 , Yahoo! Inc. 8 ******************************************************************** 9 * 10 * File SELFMT.H 11 * 12 * Modification History: 13 * 14 * Date Name Description 15 * 11/11/09 kirtig Finished first cut of implementation. 16 ********************************************************************/ 17 18 #ifndef SELFMT 19 #define SELFMT 20 21 #include "unicode/messagepattern.h" 22 #include "unicode/numfmt.h" 23 #include "unicode/utypes.h" 24 25 /** 26 * \file 27 * \brief C++ API: SelectFormat object 28 */ 29 30 #if !UCONFIG_NO_FORMATTING 31 32 U_NAMESPACE_BEGIN 33 34 class MessageFormat; 35 36 /** 37 * <p><code>SelectFormat</code> supports the creation of internationalized 38 * messages by selecting phrases based on keywords. The pattern specifies 39 * how to map keywords to phrases and provides a default phrase. The 40 * object provided to the format method is a string that's matched 41 * against the keywords. If there is a match, the corresponding phrase 42 * is selected; otherwise, the default phrase is used.</p> 43 * 44 * <h4>Using <code>SelectFormat</code> for Gender Agreement</h4> 45 * 46 * <p>Note: Typically, select formatting is done via <code>MessageFormat</code> 47 * with a <code>select</code> argument type, 48 * rather than using a stand-alone <code>SelectFormat</code>.</p> 49 * 50 * <p>The main use case for the select format is gender based inflection. 51 * When names or nouns are inserted into sentences, their gender can affect pronouns, 52 * verb forms, articles, and adjectives. Special care needs to be 53 * taken for the case where the gender cannot be determined. 54 * The impact varies between languages:</p> 55 * \htmlonly 56 * <ul> 57 * <li>English has three genders, and unknown gender is handled as a special 58 * case. Names use the gender of the named person (if known), nouns referring 59 * to people use natural gender, and inanimate objects are usually neutral. 60 * The gender only affects pronouns: "he", "she", "it", "they". 61 * 62 * <li>German differs from English in that the gender of nouns is rather 63 * arbitrary, even for nouns referring to people ("Mädchen", girl, is neutral). 64 * The gender affects pronouns ("er", "sie", "es"), articles ("der", "die", 65 * "das"), and adjective forms ("guter Mann", "gute Frau", "gutes Mädchen"). 66 * 67 * <li>French has only two genders; as in German the gender of nouns 68 * is rather arbitrary - for sun and moon, the genders 69 * are the opposite of those in German. The gender affects 70 * pronouns ("il", "elle"), articles ("le", "la"), 71 * adjective forms ("bon", "bonne"), and sometimes 72 * verb forms ("allé", "allée"). 73 * 74 * <li>Polish distinguishes five genders (or noun classes), 75 * human masculine, animate non-human masculine, inanimate masculine, 76 * feminine, and neuter. 77 * </ul> 78 * \endhtmlonly 79 * <p>Some other languages have noun classes that are not related to gender, 80 * but similar in grammatical use. 81 * Some African languages have around 20 noun classes.</p> 82 * 83 * <p><b>Note:</b>For the gender of a <i>person</i> in a given sentence, 84 * we usually need to distinguish only between female, male and other/unknown.</p> 85 * 86 * <p>To enable localizers to create sentence patterns that take their 87 * language's gender dependencies into consideration, software has to provide 88 * information about the gender associated with a noun or name to 89 * <code>MessageFormat</code>. 90 * Two main cases can be distinguished:</p> 91 * 92 * <ul> 93 * <li>For people, natural gender information should be maintained for each person. 94 * Keywords like "male", "female", "mixed" (for groups of people) 95 * and "unknown" could be used. 96 * 97 * <li>For nouns, grammatical gender information should be maintained for 98 * each noun and per language, e.g., in resource bundles. 99 * The keywords "masculine", "feminine", and "neuter" are commonly used, 100 * but some languages may require other keywords. 101 * </ul> 102 * 103 * <p>The resulting keyword is provided to <code>MessageFormat</code> as a 104 * parameter separate from the name or noun it's associated with. For example, 105 * to generate a message such as "Jean went to Paris", three separate arguments 106 * would be provided: The name of the person as argument 0, the gender of 107 * the person as argument 1, and the name of the city as argument 2. 108 * The sentence pattern for English, where the gender of the person has 109 * no impact on this simple sentence, would not refer to argument 1 at all:</p> 110 * 111 * <pre>{0} went to {2}.</pre> 112 * 113 * <p><b>Note:</b> The entire sentence should be included (and partially repeated) 114 * inside each phrase. Otherwise translators would have to be trained on how to 115 * move bits of the sentence in and out of the select argument of a message. 116 * (The examples below do not follow this recommendation!)</p> 117 * 118 * <p>The sentence pattern for French, where the gender of the person affects 119 * the form of the participle, uses a select format based on argument 1:</p> 120 * 121 * \htmlonly<pre>{0} est {1, select, female {allée} other {allé}} à {2}.</pre>\endhtmlonly 122 * 123 * <p>Patterns can be nested, so that it's possible to handle interactions of 124 * number and gender where necessary. For example, if the above sentence should 125 * allow for the names of several people to be inserted, the following sentence 126 * pattern can be used (with argument 0 the list of people's names, 127 * argument 1 the number of people, argument 2 their combined gender, and 128 * argument 3 the city name):</p> 129 * 130 * \htmlonly 131 * <pre>{0} {1, plural, 132 * one {est {2, select, female {allée} other {allé}}} 133 * other {sont {2, select, female {allées} other {allés}}} 134 * }à {3}.</pre> 135 * \endhtmlonly 136 * 137 * <h4>Patterns and Their Interpretation</h4> 138 * 139 * <p>The <code>SelectFormat</code> pattern string defines the phrase output 140 * for each user-defined keyword. 141 * The pattern is a sequence of (keyword, message) pairs. 142 * A keyword is a "pattern identifier": [^[[:Pattern_Syntax:][:Pattern_White_Space:]]]+</p> 143 * 144 * <p>Each message is a MessageFormat pattern string enclosed in {curly braces}.</p> 145 * 146 * <p>You always have to define a phrase for the default keyword 147 * <code>other</code>; this phrase is returned when the keyword 148 * provided to 149 * the <code>format</code> method matches no other keyword. 150 * If a pattern does not provide a phrase for <code>other</code>, the method 151 * it's provided to returns the error <code>U_DEFAULT_KEYWORD_MISSING</code>. 152 * <br> 153 * Pattern_White_Space between keywords and messages is ignored. 154 * Pattern_White_Space within a message is preserved and output.</p> 155 * 156 * <p><pre>Example: 157 * \htmlonly 158 * 159 * UErrorCode status = U_ZERO_ERROR; 160 * MessageFormat *msgFmt = new MessageFormat(UnicodeString("{0} est {1, select, female {allée} other {allé}} à Paris."), Locale("fr"), status); 161 * if (U_FAILURE(status)) { 162 * return; 163 * } 164 * FieldPosition ignore(FieldPosition::DONT_CARE); 165 * UnicodeString result; 166 * 167 * char* str1= "Kirti,female"; 168 * Formattable args1[] = {"Kirti","female"}; 169 * msgFmt->format(args1, 2, result, ignore, status); 170 * cout << "Input is " << str1 << " and result is: " << result << endl; 171 * delete msgFmt; 172 * 173 * \endhtmlonly 174 * </pre> 175 * </p> 176 * 177 * Produces the output:<br> 178 * \htmlonly 179 * <code>Kirti est allée à Paris.</code> 180 * \endhtmlonly 181 * 182 * @stable ICU 4.4 183 */ 184 185 class U_I18N_API SelectFormat : public Format { 186 public: 187 188 /** 189 * Creates a new <code>SelectFormat</code> for a given pattern string. 190 * @param pattern the pattern for this <code>SelectFormat</code>. 191 * errors are returned to status if the pattern is invalid. 192 * @param status output param set to success/failure code on exit, which 193 * must not indicate a failure before the function call. 194 * @stable ICU 4.4 195 */ 196 SelectFormat(const UnicodeString& pattern, UErrorCode& status); 197 198 /** 199 * copy constructor. 200 * @stable ICU 4.4 201 */ 202 SelectFormat(const SelectFormat& other); 203 204 /** 205 * Destructor. 206 * @stable ICU 4.4 207 */ 208 virtual ~SelectFormat(); 209 210 /** 211 * Sets the pattern used by this select format. 212 * for the keyword rules. 213 * Patterns and their interpretation are specified in the class description. 214 * 215 * @param pattern the pattern for this select format 216 * errors are returned to status if the pattern is invalid. 217 * @param status output param set to success/failure code on exit, which 218 * must not indicate a failure before the function call. 219 * @stable ICU 4.4 220 */ 221 void applyPattern(const UnicodeString& pattern, UErrorCode& status); 222 223 224 using Format::format; 225 226 /** 227 * Selects the phrase for the given keyword 228 * 229 * @param keyword The keyword that is used to select an alternative. 230 * @param appendTo output parameter to receive result. 231 * result is appended to existing contents. 232 * @param pos On input: an alignment field, if desired. 233 * On output: the offsets of the alignment field. 234 * @param status output param set to success/failure code on exit, which 235 * must not indicate a failure before the function call. 236 * @return Reference to 'appendTo' parameter. 237 * @stable ICU 4.4 238 */ 239 UnicodeString& format(const UnicodeString& keyword, 240 UnicodeString& appendTo, 241 FieldPosition& pos, 242 UErrorCode& status) const; 243 244 /** 245 * Assignment operator 246 * 247 * @param other the SelectFormat object to copy from. 248 * @stable ICU 4.4 249 */ 250 SelectFormat& operator=(const SelectFormat& other); 251 252 /** 253 * Return true if another object is semantically equal to this one. 254 * 255 * @param other the SelectFormat object to be compared with. 256 * @return true if other is semantically equal to this. 257 * @stable ICU 4.4 258 */ 259 virtual UBool operator==(const Format& other) const; 260 261 /** 262 * Return true if another object is semantically unequal to this one. 263 * 264 * @param other the SelectFormat object to be compared with. 265 * @return true if other is semantically unequal to this. 266 * @stable ICU 4.4 267 */ 268 virtual UBool operator!=(const Format& other) const; 269 270 /** 271 * Clones this Format object polymorphically. The caller owns the 272 * result and should delete it when done. 273 * @stable ICU 4.4 274 */ 275 virtual Format* clone(void) const; 276 277 /** 278 * Format an object to produce a string. 279 * This method handles keyword strings. 280 * If the Formattable object is not a <code>UnicodeString</code>, 281 * then it returns a failing UErrorCode. 282 * 283 * @param obj A keyword string that is used to select an alternative. 284 * @param appendTo output parameter to receive result. 285 * Result is appended to existing contents. 286 * @param pos On input: an alignment field, if desired. 287 * On output: the offsets of the alignment field. 288 * @param status output param filled with success/failure status. 289 * @return Reference to 'appendTo' parameter. 290 * @stable ICU 4.4 291 */ 292 UnicodeString& format(const Formattable& obj, 293 UnicodeString& appendTo, 294 FieldPosition& pos, 295 UErrorCode& status) const; 296 297 /** 298 * Returns the pattern from applyPattern() or constructor. 299 * 300 * @param appendTo output parameter to receive result. 301 * Result is appended to existing contents. 302 * @return the UnicodeString with inserted pattern. 303 * @stable ICU 4.4 304 */ 305 UnicodeString& toPattern(UnicodeString& appendTo); 306 307 /** 308 * This method is not yet supported by <code>SelectFormat</code>. 309 * <P> 310 * Before calling, set parse_pos.index to the offset you want to start 311 * parsing at in the source. After calling, parse_pos.index is the end of 312 * the text you parsed. If error occurs, index is unchanged. 313 * <P> 314 * When parsing, leading whitespace is discarded (with a successful parse), 315 * while trailing whitespace is left as is. 316 * <P> 317 * See Format::parseObject() for more. 318 * 319 * @param source The string to be parsed into an object. 320 * @param result Formattable to be set to the parse result. 321 * If parse fails, return contents are undefined. 322 * @param parse_pos The position to start parsing at. Upon return 323 * this param is set to the position after the 324 * last character successfully parsed. If the 325 * source is not parsed successfully, this param 326 * will remain unchanged. 327 * @stable ICU 4.4 328 */ 329 virtual void parseObject(const UnicodeString& source, 330 Formattable& result, 331 ParsePosition& parse_pos) const; 332 333 /** 334 * ICU "poor man's RTTI", returns a UClassID for this class. 335 * @stable ICU 4.4 336 */ 337 static UClassID U_EXPORT2 getStaticClassID(void); 338 339 /** 340 * ICU "poor man's RTTI", returns a UClassID for the actual class. 341 * @stable ICU 4.4 342 */ 343 virtual UClassID getDynamicClassID() const; 344 345 private: 346 friend class MessageFormat; 347 348 SelectFormat(); // default constructor not implemented. 349 350 /** 351 * Finds the SelectFormat sub-message for the given keyword, or the "other" sub-message. 352 * @param pattern A MessagePattern. 353 * @param partIndex the index of the first SelectFormat argument style part. 354 * @param keyword a keyword to be matched to one of the SelectFormat argument's keywords. 355 * @param ec Error code. 356 * @return the sub-message start part index. 357 */ 358 static int32_t findSubMessage(const MessagePattern& pattern, int32_t partIndex, 359 const UnicodeString& keyword, UErrorCode& ec); 360 361 MessagePattern msgPattern; 362 }; 363 364 U_NAMESPACE_END 365 366 #endif /* #if !UCONFIG_NO_FORMATTING */ 367 368 #endif // _SELFMT 369 //eof 370