1// © 2016 and later: Unicode, Inc. and others.
2// License & terms of use: http://www.unicode.org/copyright.html
3/*
4*******************************************************************************
5* Copyright (C) 2008-2015, International Business Machines Corporation and
6* others. All Rights Reserved.
7*******************************************************************************
8*
9*
10* File PLURRULE.H
11*
12* Modification History:*
13* Date Name Description
14*
15********************************************************************************
16*/
17
18#ifndef PLURRULE
19#define PLURRULE
20
21#include "unicode/utypes.h"
22
23#if U_SHOW_CPLUSPLUS_API
24
25/**
26 * \file
27 * \brief C++ API: PluralRules object
28 */
29
30#if !UCONFIG_NO_FORMATTING
31
32#include "unicode/format.h"
33#include "unicode/upluralrules.h"
34#ifndef U_HIDE_INTERNAL_API
35#include "unicode/numfmt.h"
36#endif /* U_HIDE_INTERNAL_API */
37
38/**
39 * Value returned by PluralRules::getUniqueKeywordValue() when there is no
40 * unique value to return.
41 * @stable ICU 4.8
42 */
43#define UPLRULES_NO_UNIQUE_VALUE ((double)-0.00123456777)
44
45U_NAMESPACE_BEGIN
46
47class Hashtable;
48class IFixedDecimal;
49class RuleChain;
50class PluralRuleParser;
51class PluralKeywordEnumeration;
52class AndConstraint;
53class SharedPluralRules;
54
55namespace number {
56class FormattedNumber;
57}
58
59/**
60 * Defines rules for mapping non-negative numeric values onto a small set of
61 * keywords. Rules are constructed from a text description, consisting
62 * of a series of keywords and conditions. The {@link #select} method
63 * examines each condition in order and returns the keyword for the
64 * first condition that matches the number. If none match,
65 * default rule(other) is returned.
66 *
67 * For more information, details, and tips for writing rules, see the
68 * LDML spec, C.11 Language Plural Rules:
69 * http://www.unicode.org/draft/reports/tr35/tr35.html#Language_Plural_Rules
70 *
71 * Examples:<pre>
72 * "one: n is 1; few: n in 2..4"</pre>
73 * This defines two rules, for 'one' and 'few'. The condition for
74 * 'one' is "n is 1" which means that the number must be equal to
75 * 1 for this condition to pass. The condition for 'few' is
76 * "n in 2..4" which means that the number must be between 2 and
77 * 4 inclusive for this condition to pass. All other numbers
78 * are assigned the keyword "other" by the default rule.
79 * </p><pre>
80 * "zero: n is 0; one: n is 1; zero: n mod 100 in 1..19"</pre>
81 * This illustrates that the same keyword can be defined multiple times.
82 * Each rule is examined in order, and the first keyword whose condition
83 * passes is the one returned. Also notes that a modulus is applied
84 * to n in the last rule. Thus its condition holds for 119, 219, 319...
85 * </p><pre>
86 * "one: n is 1; few: n mod 10 in 2..4 and n mod 100 not in 12..14"</pre>
87 * This illustrates conjunction and negation. The condition for 'few'
88 * has two parts, both of which must be met: "n mod 10 in 2..4" and
89 * "n mod 100 not in 12..14". The first part applies a modulus to n
90 * before the test as in the previous example. The second part applies
91 * a different modulus and also uses negation, thus it matches all
92 * numbers _not_ in 12, 13, 14, 112, 113, 114, 212, 213, 214...
93 * </p>
94 * <p>
95 * Syntax:<pre>
96 * \code
97 * rules = rule (';' rule)*
98 * rule = keyword ':' condition
99 * keyword = <identifier>
100 * condition = and_condition ('or' and_condition)*
101 * and_condition = relation ('and' relation)*
102 * relation = is_relation | in_relation | within_relation | 'n' <EOL>
103 * is_relation = expr 'is' ('not')? value
104 * in_relation = expr ('not')? 'in' range_list
105 * within_relation = expr ('not')? 'within' range
106 * expr = ('n' | 'i' | 'f' | 'v' | 'j') ('mod' value)?
107 * range_list = (range | value) (',' range_list)*
108 * value = digit+ ('.' digit+)?
109 * digit = 0|1|2|3|4|5|6|7|8|9
110 * range = value'..'value
111 * \endcode
112 * </pre></p>
113 * <p>
114 * <p>
115 * The i, f, and v values are defined as follows:
116 * </p>
117 * <ul>
118 * <li>i to be the integer digits.</li>
119 * <li>f to be the visible fractional digits, as an integer.</li>
120 * <li>v to be the number of visible fraction digits.</li>
121 * <li>j is defined to only match integers. That is j is 3 fails if v != 0 (eg for 3.1 or 3.0).</li>
122 * </ul>
123 * <p>
124 * Examples are in the following table:
125 * </p>
126 * <table border='1' style="border-collapse:collapse">
127 * <tr>
128 * <th>n</th>
129 * <th>i</th>
130 * <th>f</th>
131 * <th>v</th>
132 * </tr>
133 * <tr>
134 * <td>1.0</td>
135 * <td>1</td>
136 * <td align="right">0</td>
137 * <td>1</td>
138 * </tr>
139 * <tr>
140 * <td>1.00</td>
141 * <td>1</td>
142 * <td align="right">0</td>
143 * <td>2</td>
144 * </tr>
145 * <tr>
146 * <td>1.3</td>
147 * <td>1</td>
148 * <td align="right">3</td>
149 * <td>1</td>
150 * </tr>
151 * <tr>
152 * <td>1.03</td>
153 * <td>1</td>
154 * <td align="right">3</td>
155 * <td>2</td>
156 * </tr>
157 * <tr>
158 * <td>1.23</td>
159 * <td>1</td>
160 * <td align="right">23</td>
161 * <td>2</td>
162 * </tr>
163 * </table>
164 * <p>
165 * The difference between 'in' and 'within' is that 'in' only includes integers in the specified range, while 'within'
166 * includes all values. Using 'within' with a range_list consisting entirely of values is the same as using 'in' (it's
167 * not an error).
168 * </p>
169
170 * An "identifier" is a sequence of characters that do not have the
171 * Unicode Pattern_Syntax or Pattern_White_Space properties.
172 * <p>
173 * The difference between 'in' and 'within' is that 'in' only includes
174 * integers in the specified range, while 'within' includes all values.
175 * Using 'within' with a range_list consisting entirely of values is the
176 * same as using 'in' (it's not an error).
177 *</p>
178 * <p>
179 * Keywords
180 * could be defined by users or from ICU locale data. There are 6
181 * predefined values in ICU - 'zero', 'one', 'two', 'few', 'many' and
182 * 'other'. Callers need to check the value of keyword returned by
183 * {@link #select} method.
184 * </p>
185 *
186 * Examples:<pre>
187 * UnicodeString keyword = pl->select(number);
188 * if (keyword== UnicodeString("one") {
189 * ...
190 * }
191 * else if ( ... )
192 * </pre>
193 * <strong>Note:</strong><br>
194 * <p>
195 * ICU defines plural rules for many locales based on CLDR <i>Language Plural Rules</i>.
196 * For these predefined rules, see CLDR page at
197 * http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/language_plural_rules.html
198 * </p>
199 */
200class U_I18N_API PluralRules : public UObject {
201public:
202
203 /**
204 * Constructor.
205 * @param status Output param set to success/failure code on exit, which
206 * must not indicate a failure before the function call.
207 *
208 * @stable ICU 4.0
209 */
210 PluralRules(UErrorCode& status);
211
212 /**
213 * Copy constructor.
214 * @stable ICU 4.0
215 */
216 PluralRules(const PluralRules& other);
217
218 /**
219 * Destructor.
220 * @stable ICU 4.0
221 */
222 virtual ~PluralRules();
223
224 /**
225 * Clone
226 * @stable ICU 4.0
227 */
228 PluralRules* clone() const;
229
230 /**
231 * Assignment operator.
232 * @stable ICU 4.0
233 */
234 PluralRules& operator=(const PluralRules&);
235
236 /**
237 * Creates a PluralRules from a description if it is parsable, otherwise
238 * returns NULL.
239 *
240 * @param description rule description
241 * @param status Output param set to success/failure code on exit, which
242 * must not indicate a failure before the function call.
243 * @return new PluralRules pointer. NULL if there is an error.
244 * @stable ICU 4.0
245 */
246 static PluralRules* U_EXPORT2 createRules(const UnicodeString& description,
247 UErrorCode& status);
248
249 /**
250 * The default rules that accept any number.
251 *
252 * @param status Output param set to success/failure code on exit, which
253 * must not indicate a failure before the function call.
254 * @return new PluralRules pointer. NULL if there is an error.
255 * @stable ICU 4.0
256 */
257 static PluralRules* U_EXPORT2 createDefaultRules(UErrorCode& status);
258
259 /**
260 * Provides access to the predefined cardinal-number <code>PluralRules</code> for a given
261 * locale.
262 * Same as forLocale(locale, UPLURAL_TYPE_CARDINAL, status).
263 *
264 * @param locale The locale for which a <code>PluralRules</code> object is
265 * returned.
266 * @param status Output param set to success/failure code on exit, which
267 * must not indicate a failure before the function call.
268 * @return The predefined <code>PluralRules</code> object pointer for
269 * this locale. If there's no predefined rules for this locale,
270 * the rules for the closest parent in the locale hierarchy
271 * that has one will be returned. The final fallback always
272 * returns the default 'other' rules.
273 * @stable ICU 4.0
274 */
275 static PluralRules* U_EXPORT2 forLocale(const Locale& locale, UErrorCode& status);
276
277 /**
278 * Provides access to the predefined <code>PluralRules</code> for a given
279 * locale and the plural type.
280 *
281 * @param locale The locale for which a <code>PluralRules</code> object is
282 * returned.
283 * @param type The plural type (e.g., cardinal or ordinal).
284 * @param status Output param set to success/failure code on exit, which
285 * must not indicate a failure before the function call.
286 * @return The predefined <code>PluralRules</code> object pointer for
287 * this locale. If there's no predefined rules for this locale,
288 * the rules for the closest parent in the locale hierarchy
289 * that has one will be returned. The final fallback always
290 * returns the default 'other' rules.
291 * @stable ICU 50
292 */
293 static PluralRules* U_EXPORT2 forLocale(const Locale& locale, UPluralType type, UErrorCode& status);
294
295#ifndef U_HIDE_INTERNAL_API
296 /**
297 * Return a StringEnumeration over the locales for which there is plurals data.
298 * @return a StringEnumeration over the locales available.
299 * @internal
300 */
301 static StringEnumeration* U_EXPORT2 getAvailableLocales(UErrorCode &status);
302
303 /**
304 * Returns whether or not there are overrides.
305 * @param locale the locale to check.
306 * @return
307 * @internal
308 */
309 static UBool hasOverride(const Locale &locale);
310
311 /**
312 * For ICU use only.
313 * creates a SharedPluralRules object
314 * @internal
315 */
316 static PluralRules* U_EXPORT2 internalForLocale(const Locale& locale, UPluralType type, UErrorCode& status);
317
318 /**
319 * For ICU use only.
320 * Returns handle to the shared, cached PluralRules instance.
321 * Caller must call removeRef() on returned value once it is done with
322 * the shared instance.
323 * @internal
324 */
325 static const SharedPluralRules* U_EXPORT2 createSharedInstance(
326 const Locale& locale, UPluralType type, UErrorCode& status);
327
328
329#endif /* U_HIDE_INTERNAL_API */
330
331 /**
332 * Given an integer, returns the keyword of the first rule
333 * that applies to the number. This function can be used with
334 * isKeyword* functions to determine the keyword for default plural rules.
335 *
336 * @param number The number for which the rule has to be determined.
337 * @return The keyword of the selected rule.
338 * @stable ICU 4.0
339 */
340 UnicodeString select(int32_t number) const;
341
342 /**
343 * Given a floating-point number, returns the keyword of the first rule
344 * that applies to the number. This function can be used with
345 * isKeyword* functions to determine the keyword for default plural rules.
346 *
347 * @param number The number for which the rule has to be determined.
348 * @return The keyword of the selected rule.
349 * @stable ICU 4.0
350 */
351 UnicodeString select(double number) const;
352
353#ifndef U_HIDE_DRAFT_API
354 /**
355 * Given a formatted number, returns the keyword of the first rule
356 * that applies to the number. This function can be used with
357 * isKeyword* functions to determine the keyword for default plural rules.
358 *
359 * A FormattedNumber allows you to specify an exponent or trailing zeros,
360 * which can affect the plural category. To get a FormattedNumber, see
361 * NumberFormatter.
362 *
363 * @param number The number for which the rule has to be determined.
364 * @param status Set if an error occurs while selecting plural keyword.
365 * This could happen if the FormattedNumber is invalid.
366 * @return The keyword of the selected rule.
367 * @draft ICU 64
368 */
369 UnicodeString select(const number::FormattedNumber& number, UErrorCode& status) const;
370#endif /* U_HIDE_DRAFT_API */
371
372#ifndef U_HIDE_INTERNAL_API
373 /**
374 * @internal
375 */
376 UnicodeString select(const IFixedDecimal &number) const;
377#endif /* U_HIDE_INTERNAL_API */
378
379 /**
380 * Returns a list of all rule keywords used in this <code>PluralRules</code>
381 * object. The rule 'other' is always present by default.
382 *
383 * @param status Output param set to success/failure code on exit, which
384 * must not indicate a failure before the function call.
385 * @return StringEnumeration with the keywords.
386 * The caller must delete the object.
387 * @stable ICU 4.0
388 */
389 StringEnumeration* getKeywords(UErrorCode& status) const;
390
391#ifndef U_HIDE_DEPRECATED_API
392 /**
393 * Deprecated Function, does not return useful results.
394 *
395 * Originally intended to return a unique value for this keyword if it exists,
396 * else the constant UPLRULES_NO_UNIQUE_VALUE.
397 *
398 * @param keyword The keyword.
399 * @return Stub deprecated function returns UPLRULES_NO_UNIQUE_VALUE always.
400 * @deprecated ICU 55
401 */
402 double getUniqueKeywordValue(const UnicodeString& keyword);
403
404 /**
405 * Deprecated Function, does not produce useful results.
406 *
407 * Originally intended to return all the values for which select() would return the keyword.
408 * If the keyword is unknown, returns no values, but this is not an error. If
409 * the number of values is unlimited, returns no values and -1 as the
410 * count.
411 *
412 * The number of returned values is typically small.
413 *
414 * @param keyword The keyword.
415 * @param dest Array into which to put the returned values. May
416 * be NULL if destCapacity is 0.
417 * @param destCapacity The capacity of the array, must be at least 0.
418 * @param status The error code. Deprecated function, always sets U_UNSUPPORTED_ERROR.
419 * @return The count of values available, or -1. This count
420 * can be larger than destCapacity, but no more than
421 * destCapacity values will be written.
422 * @deprecated ICU 55
423 */
424 int32_t getAllKeywordValues(const UnicodeString &keyword,
425 double *dest, int32_t destCapacity,
426 UErrorCode& status);
427#endif /* U_HIDE_DEPRECATED_API */
428
429 /**
430 * Returns sample values for which select() would return the keyword. If
431 * the keyword is unknown, returns no values, but this is not an error.
432 *
433 * The number of returned values is typically small.
434 *
435 * @param keyword The keyword.
436 * @param dest Array into which to put the returned values. May
437 * be NULL if destCapacity is 0.
438 * @param destCapacity The capacity of the array, must be at least 0.
439 * @param status The error code.
440 * @return The count of values written.
441 * If more than destCapacity samples are available, then
442 * only destCapacity are written, and destCapacity is returned as the count,
443 * rather than setting a U_BUFFER_OVERFLOW_ERROR.
444 * (The actual number of keyword values could be unlimited.)
445 * @stable ICU 4.8
446 */
447 int32_t getSamples(const UnicodeString &keyword,
448 double *dest, int32_t destCapacity,
449 UErrorCode& status);
450
451 /**
452 * Returns TRUE if the given keyword is defined in this
453 * <code>PluralRules</code> object.
454 *
455 * @param keyword the input keyword.
456 * @return TRUE if the input keyword is defined.
457 * Otherwise, return FALSE.
458 * @stable ICU 4.0
459 */
460 UBool isKeyword(const UnicodeString& keyword) const;
461
462
463 /**
464 * Returns keyword for default plural form.
465 *
466 * @return keyword for default plural form.
467 * @stable ICU 4.0
468 */
469 UnicodeString getKeywordOther() const;
470
471#ifndef U_HIDE_INTERNAL_API
472 /**
473 *
474 * @internal
475 */
476 UnicodeString getRules() const;
477#endif /* U_HIDE_INTERNAL_API */
478
479 /**
480 * Compares the equality of two PluralRules objects.
481 *
482 * @param other The other PluralRules object to be compared with.
483 * @return True if the given PluralRules is the same as this
484 * PluralRules; false otherwise.
485 * @stable ICU 4.0
486 */
487 virtual UBool operator==(const PluralRules& other) const;
488
489 /**
490 * Compares the inequality of two PluralRules objects.
491 *
492 * @param other The PluralRules object to be compared with.
493 * @return True if the given PluralRules is not the same as this
494 * PluralRules; false otherwise.
495 * @stable ICU 4.0
496 */
497 UBool operator!=(const PluralRules& other) const {return !operator==(other);}
498
499
500 /**
501 * ICU "poor man's RTTI", returns a UClassID for this class.
502 *
503 * @stable ICU 4.0
504 *
505 */
506 static UClassID U_EXPORT2 getStaticClassID(void);
507
508 /**
509 * ICU "poor man's RTTI", returns a UClassID for the actual class.
510 *
511 * @stable ICU 4.0
512 */
513 virtual UClassID getDynamicClassID() const;
514
515
516private:
517 RuleChain *mRules;
518
519 PluralRules(); // default constructor not implemented
520 void parseDescription(const UnicodeString& ruleData, UErrorCode &status);
521 int32_t getNumberValue(const UnicodeString& token) const;
522 UnicodeString getRuleFromResource(const Locale& locale, UPluralType type, UErrorCode& status);
523 RuleChain *rulesForKeyword(const UnicodeString &keyword) const;
524
525 /**
526 * An internal status variable used to indicate that the object is in an 'invalid' state.
527 * Used by copy constructor, the assignment operator and the clone method.
528 */
529 UErrorCode mInternalStatus;
530
531 friend class PluralRuleParser;
532};
533
534U_NAMESPACE_END
535
536#endif /* #if !UCONFIG_NO_FORMATTING */
537
538#endif /* U_SHOW_CPLUSPLUS_API */
539
540#endif // _PLURRULE
541//eof
542