The Tor Browser: comparison intl/icu/source/i18n/unicode/plurfmt.h

--1:000000000000
+:c6e446b614cf
+/*
+*******************************************************************************
+* Copyright (C) 2007-2013, 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;
+/**
+* <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 */
+friend class MessageFormat;
+};
+U_NAMESPACE_END
+#endif /* #if !UCONFIG_NO_FORMATTING */
+#endif // _PLURFMT
+//eof

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comparison: intl/icu/source/i18n/unicode/plurfmt.h

intl/icu/source/i18n/unicode/plurfmt.h