diff options
Diffstat (limited to 'intl/icu/source/i18n/unicode/plurfmt.h')
| -rw-r--r-- | intl/icu/source/i18n/unicode/plurfmt.h | 617 |
1 files changed, 617 insertions, 0 deletions
diff --git a/intl/icu/source/i18n/unicode/plurfmt.h b/intl/icu/source/i18n/unicode/plurfmt.h new file mode 100644 index 000000000..369a8b7cc --- /dev/null +++ b/intl/icu/source/i18n/unicode/plurfmt.h @@ -0,0 +1,617 @@ +// Copyright (C) 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* +******************************************************************************* +* 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 |