/*
*******************************************************************************
* Copyright (C) 2007, 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"
U_NAMESPACE_BEGIN
class Hashtable;
class RuleChain;
class RuleParser;
/**
* Defines rules for mapping positive long 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.
*
* Examples:
* "one: n is 1; few: n in 2..4"
* 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.
*
* "zero: n is 0; one: n is 1; zero: n mod 100 in 1..19"
* 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...
*
* "one: n is 1; few: n mod 10 in 2..4 and n mod 100 not in 12..14"
* 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...
*
*
* 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.
*
*
* Examples:
* UnicodeString keyword = pl->select(number);
* if (keyword== UnicodeString("one") {
* ...
* }
* else if ( ... )
*
*/
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.
*
* @draft ICU 4.0
*/
PluralRules(UErrorCode& status);
/**
* Copy constructor.
* @draft ICU 4.0
*/
PluralRules(const PluralRules& other);
/**
* Destructor.
* @draft ICU 4.0
*/
virtual ~PluralRules();
/**
* Clone
* @draft ICU 4.0
*/
PluralRules* clone() const;
/**
* Assignment operator.
* @draft 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.
* @draft 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.
* @draft ICU 4.0
*/
static PluralRules* U_EXPORT2 createDefaultRules(UErrorCode& status);
/**
* Provides access to the predefined PluralRules for a given
* locale.
*
* @param locale The locale for which a PluralRules 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 PluralRules 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.
* @draft ICU 4.0
*/
static PluralRules* U_EXPORT2 forLocale(const Locale& locale, UErrorCode& status);
/**
* 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.
* @draft ICU 4.0
*/
UnicodeString select(int32_t number) const;
/**
* Returns a list of all rule keywords used in this PluralRules
* 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.
* @draft ICU 4.0
*/
StringEnumeration* getKeywords(UErrorCode& status) const;
/**
* Returns TRUE if the given keyword is defined in this
* PluralRules object.
*
* @param keyword the input keyword.
* @return TRUE if the input keyword is defined.
* Otherwise, return FALSE.
* @draft ICU 4.0
*/
UBool isKeyword(const UnicodeString& keyword) const;
/**
* Returns keyword for default plural form.
*
* @return keyword for default plural form.
* @internal 4.0
* @draft ICU 4.0
*/
UnicodeString getKeywordOther() const;
/**
* 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.
* @draft 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.
* @draft ICU 4.0
*/
UBool operator!=(const PluralRules& other) const {return !operator==(other);}
/**
* ICU "poor man's RTTI", returns a UClassID for this class.
*
* @draft ICU 4.0
*
*/
static UClassID U_EXPORT2 getStaticClassID(void);
/**
* ICU "poor man's RTTI", returns a UClassID for the actual class.
*
* @draft ICU 4.0
*/
virtual UClassID getDynamicClassID() const;
private:
Hashtable *fLocaleStringsHash;
UnicodeString localeName;
RuleChain *rules;
RuleParser *parser;
PluralRules(); // default constructor not implemented
void getRuleData(UErrorCode& status);
int32_t getRepeatLimit() const;
UErrorCode parseDescription(UnicodeString& ruleData, RuleChain& rules);
void getNextLocale(const UnicodeString& localeData, int32_t* curIndex, UnicodeString& localeName);
void addRules(RuleChain& rules, UErrorCode& err);
void addRules(const UnicodeString& localeName, RuleChain& rules, UBool addToHash, UErrorCode& err);
void initHashtable(UErrorCode& err);
int32_t getNumberValue(const UnicodeString& token) const;
};
U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_FORMATTING */
#endif // _PLURRULE
//eof