// Copyright (C) 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 2008-2015, International Business Machines Corporation and
* others. All Rights Reserved.
*******************************************************************************
*
*
* File PLURRULE.H
*
* Modification History:*
* Date Name Description
*
********************************************************************************
*/
#ifndef PLURRULE
#define PLURRULE
#include "unicode/utypes.h"
/**
* \file
* \brief C++ API: PluralRules object
*/
#if !UCONFIG_NO_FORMATTING
#include "unicode/format.h"
#include "unicode/upluralrules.h"
/**
* Value returned by PluralRules::getUniqueKeywordValue() when there is no
* unique value to return.
* @stable ICU 4.8
*/
#define UPLRULES_NO_UNIQUE_VALUE ((double)-0.00123456777)
U_NAMESPACE_BEGIN
class Hashtable;
class FixedDecimal;
class VisibleDigitsWithExponent;
class RuleChain;
class PluralRuleParser;
class PluralKeywordEnumeration;
class AndConstraint;
class SharedPluralRules;
/**
* Defines rules for mapping non-negative numeric values onto a small set of
* keywords. Rules are constructed from a text description, consisting
* of a series of keywords and conditions. The {@link #select} method
* examines each condition in order and returns the keyword for the
* first condition that matches the number. If none match,
* default rule(other) is returned.
*
* For more information, details, and tips for writing rules, see the
* LDML spec, C.11 Language Plural Rules:
* http://www.unicode.org/draft/reports/tr35/tr35.html#Language_Plural_Rules
*
* Examples:<pre>
* "one: n is 1; few: n in 2..4"</pre>
* This defines two rules, for 'one' and 'few'. The condition for
* 'one' is "n is 1" which means that the number must be equal to
* 1 for this condition to pass. The condition for 'few' is
* "n in 2..4" which means that the number must be between 2 and
* 4 inclusive for this condition to pass. All other numbers
* are assigned the keyword "other" by the default rule.
* </p><pre>
* "zero: n is 0; one: n is 1; zero: n mod 100 in 1..19"</pre>
* This illustrates that the same keyword can be defined multiple times.
* Each rule is examined in order, and the first keyword whose condition
* passes is the one returned. Also notes that a modulus is applied
* to n in the last rule. Thus its condition holds for 119, 219, 319...
* </p><pre>
* "one: n is 1; few: n mod 10 in 2..4 and n mod 100 not in 12..14"</pre>
* This illustrates conjunction and negation. The condition for 'few'
* has two parts, both of which must be met: "n mod 10 in 2..4" and
* "n mod 100 not in 12..14". The first part applies a modulus to n
* before the test as in the previous example. The second part applies
* a different modulus and also uses negation, thus it matches all
* numbers _not_ in 12, 13, 14, 112, 113, 114, 212, 213, 214...
* </p>
* <p>
* Syntax:<pre>
* \code
* rules = rule (';' rule)*
* rule = keyword ':' condition
* keyword = <identifier>
* condition = and_condition ('or' and_condition)*
* and_condition = relation ('and' relation)*
* relation = is_relation | in_relation | within_relation | 'n' <EOL>
* is_relation = expr 'is' ('not')? value
* in_relation = expr ('not')? 'in' range_list
* within_relation = expr ('not')? 'within' range
* expr = ('n' | 'i' | 'f' | 'v' | 'j') ('mod' value)?
* range_list = (range | value) (',' range_list)*
* value = digit+ ('.' digit+)?
* digit = 0|1|2|3|4|5|6|7|8|9
* range = value'..'value
* \endcode
* </pre></p>
* <p>
* <p>
* The i, f, and v values are defined as follows:
* </p>
* <ul>
* <li>i to be the integer digits.</li>
* <li>f to be the visible fractional digits, as an integer.</li>
* <li>v to be the number of visible fraction digits.</li>
* <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>
* </ul>
* <p>
* Examples are in the following table:
* </p>
* <table border='1' style="border-collapse:collapse">
* <tbody>
* <tr>
* <th>n</th>
* <th>i</th>
* <th>f</th>
* <th>v</th>
* </tr>
* <tr>
* <td>1.0</td>
* <td>1</td>
* <td align="right">0</td>
* <td>1</td>
* </tr>
* <tr>
* <td>1.00</td>
* <td>1</td>
* <td align="right">0</td>
* <td>2</td>
* </tr>
* <tr>
* <td>1.3</td>
* <td>1</td>
* <td align="right">3</td>
* <td>1</td>
* </tr>
* <tr>
* <td>1.03</td>
* <td>1</td>
* <td align="right">3</td>
* <td>2</td>
* </tr>
* <tr>
* <td>1.23</td>
* <td>1</td>
* <td align="right">23</td>
* <td>2</td>
* </tr>
* </tbody>
* </table>
* <p>
* The difference between 'in' and 'within' is that 'in' only includes integers in the specified range, while 'within'
* includes all values. Using 'within' with a range_list consisting entirely of values is the same as using 'in' (it's
* not an error).
* </p>
* An "identifier" is a sequence of characters that do not have the
* Unicode Pattern_Syntax or Pattern_White_Space properties.
* <p>
* The difference between 'in' and 'within' is that 'in' only includes
* integers in the specified range, while 'within' includes all values.
* Using 'within' with a range_list consisting entirely of values is the
* same as using 'in' (it's not an error).
*</p>
* <p>
* Keywords
* could be defined by users or from ICU locale data. There are 6
* predefined values in ICU - 'zero', 'one', 'two', 'few', 'many' and
* 'other'. Callers need to check the value of keyword returned by
* {@link #select} method.
* </p>
*
* Examples:<pre>
* UnicodeString keyword = pl->select(number);
* if (keyword== UnicodeString("one") {
* ...
* }
* else if ( ... )
* </pre>
* <strong>Note:</strong><br>
* <p>
* ICU defines plural rules for many locales based on CLDR <i>Language Plural Rules</i>.
* For these predefined rules, see CLDR page at
* http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/language_plural_rules.html
* </p>
*/
class U_I18N_API PluralRules : public UObject {
public:
/**
* Constructor.
* @param status Output param set to success/failure code on exit, which
* must not indicate a failure before the function call.
*
* @stable ICU 4.0
*/
PluralRules(UErrorCode& status);
/**
* Copy constructor.
* @stable ICU 4.0
*/
PluralRules(const PluralRules& other);
/**
* Destructor.
* @stable ICU 4.0
*/
virtual ~PluralRules();
/**
* Clone
* @stable ICU 4.0
*/
PluralRules* clone() const;
/**
* Assignment operator.
* @stable ICU 4.0
*/
PluralRules& operator=(const PluralRules&);
/**
* Creates a PluralRules from a description if it is parsable, otherwise
* returns NULL.
*
* @param description rule description
* @param status Output param set to success/failure code on exit, which
* must not indicate a failure before the function call.
* @return new PluralRules pointer. NULL if there is an error.
* @stable ICU 4.0
*/
static PluralRules* U_EXPORT2 createRules(const UnicodeString& description,
UErrorCode& status);
/**
* The default rules that accept any number.
*
* @param status Output param set to success/failure code on exit, which
* must not indicate a failure before the function call.
* @return new PluralRules pointer. NULL if there is an error.
* @stable ICU 4.0
*/
static PluralRules* U_EXPORT2 createDefaultRules(UErrorCode& status);
/**
* Provides access to the predefined cardinal-number <code>PluralRules</code> for a given
* locale.
* Same as forLocale(locale, UPLURAL_TYPE_CARDINAL, status).
*
* @param locale The locale for which a <code>PluralRules</code> object is
* returned.
* @param status Output param set to success/failure code on exit, which
* must not indicate a failure before the function call.
* @return The predefined <code>PluralRules</code> object pointer for
* this locale. If there's no predefined rules for this locale,
* the rules for the closest parent in the locale hierarchy
* that has one will be returned. The final fallback always
* returns the default 'other' rules.
* @stable ICU 4.0
*/
static PluralRules* U_EXPORT2 forLocale(const Locale& locale, UErrorCode& status);
/**
* Provides access to the predefined <code>PluralRules</code> for a given
* locale and the plural type.
*
* @param locale The locale for which a <code>PluralRules</code> object is
* returned.
* @param type The plural type (e.g., cardinal or ordinal).
* @param status Output param set to success/failure code on exit, which
* must not indicate a failure before the function call.
* @return The predefined <code>PluralRules</code> object pointer for
* this locale. If there's no predefined rules for this locale,
* the rules for the closest parent in the locale hierarchy
* that has one will be returned. The final fallback always
* returns the default 'other' rules.
* @stable ICU 50
*/
static PluralRules* U_EXPORT2 forLocale(const Locale& locale, UPluralType type, UErrorCode& status);
#ifndef U_HIDE_INTERNAL_API
/**
* Return a StringEnumeration over the locales for which there is plurals data.
* @return a StringEnumeration over the locales available.
* @internal
*/
static StringEnumeration* U_EXPORT2 getAvailableLocales(UErrorCode &status);
/**
* Returns whether or not there are overrides.
* @param locale the locale to check.
* @return
* @internal
*/
static UBool hasOverride(const Locale &locale);
/**
* For ICU use only.
* creates a SharedPluralRules object
* @internal
*/
static PluralRules* U_EXPORT2 internalForLocale(const Locale& locale, UPluralType type, UErrorCode& status);
/**
* For ICU use only.
* Returns handle to the shared, cached PluralRules instance.
* Caller must call removeRef() on returned value once it is done with
* the shared instance.
* @internal
*/
static const SharedPluralRules* U_EXPORT2 createSharedInstance(
const Locale& locale, UPluralType type, UErrorCode& status);
#endif /* U_HIDE_INTERNAL_API */
/**
* Given a number, returns the keyword of the first rule that applies to
* the number. This function can be used with isKeyword* functions to
* determine the keyword for default plural rules.
*
* @param number The number for which the rule has to be determined.
* @return The keyword of the selected rule.
* @stable ICU 4.0
*/
UnicodeString select(int32_t number) const;
/**
* Given a number, returns the keyword of the first rule that applies to
* the number. This function can be used with isKeyword* functions to
* determine the keyword for default plural rules.
*
* @param number The number for which the rule has to be determined.
* @return The keyword of the selected rule.
* @stable ICU 4.0
*/
UnicodeString select(double number) const;
#ifndef U_HIDE_INTERNAL_API
/**
* @internal
*/
UnicodeString select(const FixedDecimal &number) const;
/**
* @internal
*/
UnicodeString select(const VisibleDigitsWithExponent &number) const;
#endif /* U_HIDE_INTERNAL_API */
/**
* Returns a list of all rule keywords used in this <code>PluralRules</code>
* object. The rule 'other' is always present by default.
*
* @param status Output param set to success/failure code on exit, which
* must not indicate a failure before the function call.
* @return StringEnumeration with the keywords.
* The caller must delete the object.
* @stable ICU 4.0
*/
StringEnumeration* getKeywords(UErrorCode& status) const;
#ifndef U_HIDE_DEPRECATED_API
/**
* Deprecated Function, does not return useful results.
*
* Originally intended to return a unique value for this keyword if it exists,
* else the constant UPLRULES_NO_UNIQUE_VALUE.
*
* @param keyword The keyword.
* @return Stub deprecated function returns UPLRULES_NO_UNIQUE_VALUE always.
* @deprecated ICU 55
*/
double getUniqueKeywordValue(const UnicodeString& keyword);
/**
* Deprecated Function, does not produce useful results.
*
* Orginally intended to return all the values for which select() would return the keyword.
* If the keyword is unknown, returns no values, but this is not an error. If
* the number of values is unlimited, returns no values and -1 as the
* count.
*
* The number of returned values is typically small.
*
* @param keyword The keyword.
* @param dest Array into which to put the returned values. May
* be NULL if destCapacity is 0.
* @param destCapacity The capacity of the array, must be at least 0.
* @param status The error code. Deprecated function, always sets U_UNSUPPORTED_ERROR.
* @return The count of values available, or -1. This count
* can be larger than destCapacity, but no more than
* destCapacity values will be written.
* @deprecated ICU 55
*/
int32_t getAllKeywordValues(const UnicodeString &keyword,
double *dest, int32_t destCapacity,
UErrorCode& status);
#endif /* U_HIDE_DEPRECATED_API */
/**
* Returns sample values for which select() would return the keyword. If
* the keyword is unknown, returns no values, but this is not an error.
*
* The number of returned values is typically small.
*
* @param keyword The keyword.
* @param dest Array into which to put the returned values. May
* be NULL if destCapacity is 0.
* @param destCapacity The capacity of the array, must be at least 0.
* @param status The error code.
* @return The count of values written.
* If more than destCapacity samples are available, then
* only destCapacity are written, and destCapacity is returned as the count,
* rather than setting a U_BUFFER_OVERFLOW_ERROR.
* (The actual number of keyword values could be unlimited.)
* @stable ICU 4.8
*/
int32_t getSamples(const UnicodeString &keyword,
double *dest, int32_t destCapacity,
UErrorCode& status);
/**
* Returns TRUE if the given keyword is defined in this
* <code>PluralRules</code> object.
*
* @param keyword the input keyword.
* @return TRUE if the input keyword is defined.
* Otherwise, return FALSE.
* @stable ICU 4.0
*/
UBool isKeyword(const UnicodeString& keyword) const;
/**
* Returns keyword for default plural form.
*
* @return keyword for default plural form.
* @stable ICU 4.0
*/
UnicodeString getKeywordOther() const;
#ifndef U_HIDE_INTERNAL_API
/**
*
* @internal
*/
UnicodeString getRules() const;
#endif /* U_HIDE_INTERNAL_API */
/**
* Compares the equality of two PluralRules objects.
*
* @param other The other PluralRules object to be compared with.
* @return True if the given PluralRules is the same as this
* PluralRules; false otherwise.
* @stable ICU 4.0
*/
virtual UBool operator==(const PluralRules& other) const;
/**
* Compares the inequality of two PluralRules objects.
*
* @param other The PluralRules object to be compared with.
* @return True if the given PluralRules is not the same as this
* PluralRules; false otherwise.
* @stable ICU 4.0
*/
UBool operator!=(const PluralRules& other) const {return !operator==(other);}
/**
* ICU "poor man's RTTI", returns a UClassID for this class.
*
* @stable ICU 4.0
*
*/
static UClassID U_EXPORT2 getStaticClassID(void);
/**
* ICU "poor man's RTTI", returns a UClassID for the actual class.
*
* @stable ICU 4.0
*/
virtual UClassID getDynamicClassID() const;
private:
RuleChain *mRules;
PluralRules(); // default constructor not implemented
void parseDescription(const UnicodeString& ruleData, UErrorCode &status);
int32_t getNumberValue(const UnicodeString& token) const;
UnicodeString getRuleFromResource(const Locale& locale, UPluralType type, UErrorCode& status);
RuleChain *rulesForKeyword(const UnicodeString &keyword) const;
friend class PluralRuleParser;
};
U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_FORMATTING */
#endif // _PLURRULE
//eof