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