/* ******************************************************************************* * Copyright (C) 2007-2014, International Business Machines Corporation and * others. All Rights Reserved. ******************************************************************************* * * File PLURFMT.H ******************************************************************************** */ #ifndef PLURFMT #define PLURFMT #include "unicode/utypes.h" /** * \file * \brief C++ API: PluralFormat object */ #if !UCONFIG_NO_FORMATTING #include "unicode/messagepattern.h" #include "unicode/numfmt.h" #include "unicode/plurrule.h" U_NAMESPACE_BEGIN class Hashtable; class NFRule; /** * <p> * <code>PluralFormat</code> supports the creation of internationalized * messages with plural inflection. It is based on <i>plural * selection</i>, i.e. the caller specifies messages for each * plural case that can appear in the user's language and the * <code>PluralFormat</code> selects the appropriate message based on * the number. * </p> * <h4>The Problem of Plural Forms in Internationalized Messages</h4> * <p> * Different languages have different ways to inflect * plurals. Creating internationalized messages that include plural * forms is only feasible when the framework is able to handle plural * forms of <i>all</i> languages correctly. <code>ChoiceFormat</code> * doesn't handle this well, because it attaches a number interval to * each message and selects the message whose interval contains a * given number. This can only handle a finite number of * intervals. But in some languages, like Polish, one plural case * applies to infinitely many intervals (e.g., the plural case applies to * numbers ending with 2, 3, or 4 except those ending with 12, 13, or * 14). Thus <code>ChoiceFormat</code> is not adequate. * </p><p> * <code>PluralFormat</code> deals with this by breaking the problem * into two parts: * <ul> * <li>It uses <code>PluralRules</code> that can define more complex * conditions for a plural case than just a single interval. These plural * rules define both what plural cases exist in a language, and to * which numbers these cases apply. * <li>It provides predefined plural rules for many languages. Thus, the programmer * need not worry about the plural cases of a language and * does not have to define the plural cases; they can simply * use the predefined keywords. The whole plural formatting of messages can * be done using localized patterns from resource bundles. For predefined plural * rules, see the CLDR <i>Language Plural Rules</i> page at * http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/language_plural_rules.html * </ul> * </p> * <h4>Usage of <code>PluralFormat</code></h4> * <p>Note: Typically, plural formatting is done via <code>MessageFormat</code> * with a <code>plural</code> argument type, * rather than using a stand-alone <code>PluralFormat</code>. * </p><p> * This discussion assumes that you use <code>PluralFormat</code> with * a predefined set of plural rules. You can create one using one of * the constructors that takes a <code>locale</code> object. To * specify the message pattern, you can either pass it to the * constructor or set it explicitly using the * <code>applyPattern()</code> method. The <code>format()</code> * method takes a number object and selects the message of the * matching plural case. This message will be returned. * </p> * <h5>Patterns and Their Interpretation</h5> * <p> * The pattern text defines the message output for each plural case of the * specified locale. Syntax: * <pre> * pluralStyle = [offsetValue] (selector '{' message '}')+ * offsetValue = "offset:" number * selector = explicitValue | keyword * explicitValue = '=' number // adjacent, no white space in between * keyword = [^[[:Pattern_Syntax:][:Pattern_White_Space:]]]+ * message: see {@link MessageFormat} * </pre> * Pattern_White_Space between syntax elements is ignored, except * between the {curly braces} and their sub-message, * and between the '=' and the number of an explicitValue. * * </p><p> * There are 6 predefined casekeyword in CLDR/ICU - 'zero', 'one', 'two', 'few', 'many' and * 'other'. You always have to define a message text for the default plural case * <code>other</code> which is contained in every rule set. * If you do not specify a message text for a particular plural case, the * message text of the plural case <code>other</code> gets assigned to this * plural case. * </p><p> * When formatting, the input number is first matched against the explicitValue clauses. * If there is no exact-number match, then a keyword is selected by calling * the <code>PluralRules</code> with the input number <em>minus the offset</em>. * (The offset defaults to 0 if it is omitted from the pattern string.) * If there is no clause with that keyword, then the "other" clauses is returned. * </p><p> * An unquoted pound sign (<code>#</code>) in the selected sub-message * itself (i.e., outside of arguments nested in the sub-message) * is replaced by the input number minus the offset. * The number-minus-offset value is formatted using a * <code>NumberFormat</code> for the <code>PluralFormat</code>'s locale. If you * need special number formatting, you have to use a <code>MessageFormat</code> * and explicitly specify a <code>NumberFormat</code> argument. * <strong>Note:</strong> That argument is formatting without subtracting the offset! * If you need a custom format and have a non-zero offset, then you need to pass the * number-minus-offset value as a separate parameter. * </p> * For a usage example, see the {@link MessageFormat} class documentation. * * <h4>Defining Custom Plural Rules</h4> * <p>If you need to use <code>PluralFormat</code> with custom rules, you can * create a <code>PluralRules</code> object and pass it to * <code>PluralFormat</code>'s constructor. If you also specify a locale in this * constructor, this locale will be used to format the number in the message * texts. * </p><p> * For more information about <code>PluralRules</code>, see * {@link PluralRules}. * </p> * * ported from Java * @stable ICU 4.0 */ class U_I18N_API PluralFormat : public Format { public: /** * Creates a new cardinal-number <code>PluralFormat</code> for the default locale. * This locale will be used to get the set of plural rules and for standard * number formatting. * @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 */ PluralFormat(UErrorCode& status); /** * Creates a new cardinal-number <code>PluralFormat</code> for a given locale. * @param locale the <code>PluralFormat</code> will be configured with * rules for this locale. This locale will also be used for * standard number formatting. * @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 */ PluralFormat(const Locale& locale, UErrorCode& status); /** * Creates a new <code>PluralFormat</code> for a given set of rules. * The standard number formatting will be done using the default locale. * @param rules defines the behavior of the <code>PluralFormat</code> * object. * @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 */ PluralFormat(const PluralRules& rules, UErrorCode& status); /** * Creates a new <code>PluralFormat</code> for a given set of rules. * The standard number formatting will be done using the given locale. * @param locale the default number formatting will be done using this * locale. * @param rules defines the behavior of the <code>PluralFormat</code> * object. * @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 * <p> * <h4>Sample code</h4> * \snippet samples/plurfmtsample/plurfmtsample.cpp PluralFormatExample1 * \snippet samples/plurfmtsample/plurfmtsample.cpp PluralFormatExample * <p> */ PluralFormat(const Locale& locale, const PluralRules& rules, UErrorCode& status); /** * Creates a new <code>PluralFormat</code> for the plural type. * The standard number formatting will be done using the given locale. * @param locale the default number formatting will be done using this * locale. * @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. * @stable ICU 50 */ PluralFormat(const Locale& locale, UPluralType type, UErrorCode& status); /** * Creates a new cardinal-number <code>PluralFormat</code> for a given pattern string. * The default locale will be used to get the set of plural rules and for * standard number formatting. * @param pattern the pattern for this <code>PluralFormat</code>. * errors are returned to status if the pattern is invalid. * @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 */ PluralFormat(const UnicodeString& pattern, UErrorCode& status); /** * Creates a new cardinal-number <code>PluralFormat</code> for a given pattern string and * locale. * The locale will be used to get the set of plural rules and for * standard number formatting. * @param locale the <code>PluralFormat</code> will be configured with * rules for this locale. This locale will also be used for * standard number formatting. * @param pattern the pattern for this <code>PluralFormat</code>. * errors are returned to status if the pattern is invalid. * @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 */ PluralFormat(const Locale& locale, const UnicodeString& pattern, UErrorCode& status); /** * Creates a new <code>PluralFormat</code> for a given set of rules, a * pattern and a locale. * @param rules defines the behavior of the <code>PluralFormat</code> * object. * @param pattern the pattern for this <code>PluralFormat</code>. * errors are returned to status if the pattern is invalid. * @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 */ PluralFormat(const PluralRules& rules, const UnicodeString& pattern, UErrorCode& status); /** * Creates a new <code>PluralFormat</code> for a given set of rules, a * pattern and a locale. * @param locale the <code>PluralFormat</code> will be configured with * rules for this locale. This locale will also be used for * standard number formatting. * @param rules defines the behavior of the <code>PluralFormat</code> * object. * @param pattern the pattern for this <code>PluralFormat</code>. * errors are returned to status if the pattern is invalid. * @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 */ PluralFormat(const Locale& locale, const PluralRules& rules, const UnicodeString& pattern, UErrorCode& status); /** * Creates a new <code>PluralFormat</code> for a plural type, a * pattern and a locale. * @param locale the <code>PluralFormat</code> will be configured with * rules for this locale. This locale will also be used for * standard number formatting. * @param type The plural type (e.g., cardinal or ordinal). * @param pattern the pattern for this <code>PluralFormat</code>. * errors are returned to status if the pattern is invalid. * @param status output param set to success/failure code on exit, which * must not indicate a failure before the function call. * @stable ICU 50 */ PluralFormat(const Locale& locale, UPluralType type, const UnicodeString& pattern, UErrorCode& status); /** * copy constructor. * @stable ICU 4.0 */ PluralFormat(const PluralFormat& other); /** * Destructor. * @stable ICU 4.0 */ virtual ~PluralFormat(); /** * Sets the pattern used by this plural format. * The method parses the pattern and creates a map of format strings * for the plural rules. * Patterns and their interpretation are specified in the class description. * * @param pattern the pattern for this plural format * errors are returned to status if the pattern is invalid. * @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 */ void applyPattern(const UnicodeString& pattern, UErrorCode& status); using Format::format; /** * Formats a plural message for a given number. * * @param number a number for which the plural message should be formatted * for. If no pattern has been applied to this * <code>PluralFormat</code> object yet, the formatted number * will be returned. * @param status output param set to success/failure code on exit, which * must not indicate a failure before the function call. * @return the string containing the formatted plural message. * @stable ICU 4.0 */ UnicodeString format(int32_t number, UErrorCode& status) const; /** * Formats a plural message for a given number. * * @param number a number for which the plural message should be formatted * for. If no pattern has been applied to this * PluralFormat object yet, the formatted number * will be returned. * @param status output param set to success or failure code on exit, which * must not indicate a failure before the function call. * @return the string containing the formatted plural message. * @stable ICU 4.0 */ UnicodeString format(double number, UErrorCode& status) const; /** * Formats a plural message for a given number. * * @param number a number for which the plural message should be formatted * for. If no pattern has been applied to this * <code>PluralFormat</code> object yet, the formatted number * will be returned. * @param appendTo output parameter to receive result. * result is appended to existing contents. * @param pos On input: an alignment field, if desired. * On output: the offsets of the alignment field. * @param status output param set to success/failure code on exit, which * must not indicate a failure before the function call. * @return the string containing the formatted plural message. * @stable ICU 4.0 */ UnicodeString& format(int32_t number, UnicodeString& appendTo, FieldPosition& pos, UErrorCode& status) const; /** * Formats a plural message for a given number. * * @param number a number for which the plural message should be formatted * for. If no pattern has been applied to this * PluralFormat object yet, the formatted number * will be returned. * @param appendTo output parameter to receive result. * result is appended to existing contents. * @param pos On input: an alignment field, if desired. * On output: the offsets of the alignment field. * @param status output param set to success/failure code on exit, which * must not indicate a failure before the function call. * @return the string containing the formatted plural message. * @stable ICU 4.0 */ UnicodeString& format(double number, UnicodeString& appendTo, FieldPosition& pos, UErrorCode& status) const; #ifndef U_HIDE_DEPRECATED_API /** * Sets the locale used by this <code>PluraFormat</code> object. * Note: Calling this method resets this <code>PluraFormat</code> object, * i.e., a pattern that was applied previously will be removed, * and the NumberFormat is set to the default number format for * the locale. The resulting format behaves the same as one * constructed from {@link #PluralFormat(const Locale& locale, UPluralType type, UErrorCode& status)} * with UPLURAL_TYPE_CARDINAL. * @param locale the <code>locale</code> to use to configure the formatter. * @param status output param set to success/failure code on exit, which * must not indicate a failure before the function call. * @deprecated ICU 50 This method clears the pattern and might create * a different kind of PluralRules instance; * use one of the constructors to create a new instance instead. */ void setLocale(const Locale& locale, UErrorCode& status); #endif /* U_HIDE_DEPRECATED_API */ /** * Sets the number format used by this formatter. You only need to * call this if you want a different number format than the default * formatter for the locale. * @param format the number format to use. * @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 */ void setNumberFormat(const NumberFormat* format, UErrorCode& status); /** * Assignment operator * * @param other the PluralFormat object to copy from. * @stable ICU 4.0 */ PluralFormat& operator=(const PluralFormat& other); /** * Return true if another object is semantically equal to this one. * * @param other the PluralFormat object to be compared with. * @return true if other is semantically equal to this. * @stable ICU 4.0 */ virtual UBool operator==(const Format& other) const; /** * Return true if another object is semantically unequal to this one. * * @param other the PluralFormat object to be compared with. * @return true if other is semantically unequal to this. * @stable ICU 4.0 */ virtual UBool operator!=(const Format& other) const; /** * Clones this Format object polymorphically. The caller owns the * result and should delete it when done. * @stable ICU 4.0 */ virtual Format* clone(void) const; /** * Formats a plural message for a number taken from a Formattable object. * * @param obj The object containing a number for which the * plural message should be formatted. * The object must be of a numeric type. * @param appendTo output parameter to receive result. * Result is appended to existing contents. * @param pos On input: an alignment field, if desired. * On output: the offsets of the alignment field. * @param status output param filled with success/failure status. * @return Reference to 'appendTo' parameter. * @stable ICU 4.0 */ UnicodeString& format(const Formattable& obj, UnicodeString& appendTo, FieldPosition& pos, UErrorCode& status) const; /** * Returns the pattern from applyPattern() or constructor(). * * @param appendTo output parameter to receive result. * Result is appended to existing contents. * @return the UnicodeString with inserted pattern. * @stable ICU 4.0 */ UnicodeString& toPattern(UnicodeString& appendTo); /** * This method is not yet supported by <code>PluralFormat</code>. * <P> * Before calling, set parse_pos.index to the offset you want to start * parsing at in the source. After calling, parse_pos.index is the end of * the text you parsed. If error occurs, index is unchanged. * <P> * When parsing, leading whitespace is discarded (with a successful parse), * while trailing whitespace is left as is. * <P> * See Format::parseObject() for more. * * @param source The string to be parsed into an object. * @param result Formattable to be set to the parse result. * If parse fails, return contents are undefined. * @param parse_pos The position to start parsing at. Upon return * this param is set to the position after the * last character successfully parsed. If the * source is not parsed successfully, this param * will remain unchanged. * @stable ICU 4.0 */ virtual void parseObject(const UnicodeString& source, Formattable& result, ParsePosition& parse_pos) const; /** * 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; #if (defined(__xlC__) && (__xlC__ < 0x0C00)) || (U_PLATFORM == U_PF_OS390) || (U_PLATFORM ==U_PF_OS400) // Work around a compiler bug on xlC 11.1 on AIX 7.1 that would // prevent PluralSelectorAdapter from implementing private PluralSelector. // xlC error message: // 1540-0300 (S) The "private" member "class icu_49::PluralFormat::PluralSelector" cannot be accessed. public: #else private: #endif /** * @internal */ class U_I18N_API PluralSelector : public UMemory { public: virtual ~PluralSelector(); /** * Given a number, returns the appropriate PluralFormat keyword. * * @param context worker object for the selector. * @param number The number to be plural-formatted. * @param ec Error code. * @return The selected PluralFormat keyword. * @internal */ virtual UnicodeString select(void *context, double number, UErrorCode& ec) const = 0; }; /** * @internal */ class U_I18N_API PluralSelectorAdapter : public PluralSelector { public: PluralSelectorAdapter() : pluralRules(NULL) { } virtual ~PluralSelectorAdapter(); virtual UnicodeString select(void *context, double number, UErrorCode& /*ec*/) const; /**< @internal */ void reset(); PluralRules* pluralRules; }; #if defined(__xlC__) // End of xlC bug workaround, keep remaining definitions private. private: #endif Locale locale; MessagePattern msgPattern; NumberFormat* numberFormat; double offset; PluralSelectorAdapter pluralRulesWrapper; PluralFormat(); // default constructor not implemented void init(const PluralRules* rules, UPluralType type, UErrorCode& status); /** * Copies dynamically allocated values (pointer fields). * Others are copied using their copy constructors and assignment operators. */ void copyObjects(const PluralFormat& other); UnicodeString& format(const Formattable& numberObject, double number, UnicodeString& appendTo, FieldPosition& pos, UErrorCode& status) const; /**< @internal */ /** * Finds the PluralFormat sub-message for the given number, or the "other" sub-message. * @param pattern A MessagePattern. * @param partIndex the index of the first PluralFormat argument style part. * @param selector the PluralSelector for mapping the number (minus offset) to a keyword. * @param context worker object for the selector. * @param number a number to be matched to one of the PluralFormat argument's explicit values, * or mapped via the PluralSelector. * @param ec ICU error code. * @return the sub-message start part index. */ static int32_t findSubMessage( const MessagePattern& pattern, int32_t partIndex, const PluralSelector& selector, void *context, double number, UErrorCode& ec); /**< @internal */ void parseType(const UnicodeString& source, const NFRule *rbnfLenientScanner, Formattable& result, FieldPosition& pos) const; friend class MessageFormat; friend class NFRule; }; U_NAMESPACE_END #endif /* #if !UCONFIG_NO_FORMATTING */ #endif // _PLURFMT //eof