icuSources/i18n/unicode/upluralrules.h

   1 // © 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 /*
   4 *****************************************************************************************
   5 * Copyright (C) 2010-2013, International Business Machines
   6 * Corporation and others. All Rights Reserved.
   7 *****************************************************************************************
   8 */
   9
  10 #ifndef UPLURALRULES_H
  11 #define UPLURALRULES_H
  12
  13 #include "unicode/utypes.h"
  14
  15 #if !UCONFIG_NO_FORMATTING
  16
  17 #include "unicode/localpointer.h"
  18 #include "unicode/uenum.h"
  19 #ifndef U_HIDE_INTERNAL_API
  20 #include "unicode/unum.h"
  21 #endif  /* U_HIDE_INTERNAL_API */
  22
  23 // Forward-declaration
  24 struct UFormattedNumber;
  25
  26 /**
  27  * \file
  28  * \brief C API: Plural rules, select plural keywords for numeric values.
  29  *
  30  * A UPluralRules object defines rules for mapping non-negative numeric
  31  * values onto a small set of keywords. Rules are constructed from a text
  32  * description, consisting of a series of keywords and conditions.
  33  * The uplrules_select function examines each condition in order and
  34  * returns the keyword for the first condition that matches the number.
  35  * If none match, the default rule(other) is returned.
  36  *
  37  * For more information, see the LDML spec, C.11 Language Plural Rules:
  38  * http://www.unicode.org/reports/tr35/#Language_Plural_Rules
  39  *
  40  * Keywords: ICU locale data has 6 predefined values -
  41  * 'zero', 'one', 'two', 'few', 'many' and 'other'. Callers need to check
  42  * the value of keyword returned by the uplrules_select function.
  43  *
  44  * These are based on CLDR <i>Language Plural Rules</i>. For these
  45  * predefined rules, see the CLDR page at
  46  * http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/language_plural_rules.html
  47  */
  48
  49 /**
  50  * Type of plurals and PluralRules.
  51  * @stable ICU 50
  52  */
  53 enum UPluralType {
  54     /**
  55      * Plural rules for cardinal numbers: 1 file vs. 2 files.
  56      * @stable ICU 50
  57      */
  58     UPLURAL_TYPE_CARDINAL,
  59     /**
  60      * Plural rules for ordinal numbers: 1st file, 2nd file, 3rd file, 4th file, etc.
  61      * @stable ICU 50
  62      */
  63     UPLURAL_TYPE_ORDINAL,
  64 #ifndef U_HIDE_DEPRECATED_API
  65     /**
  66      * One more than the highest normal UPluralType value.
  67      * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
  68      */
  69     UPLURAL_TYPE_COUNT
  70 #endif  /* U_HIDE_DEPRECATED_API */
  71 };
  72 /**
  73  * @stable ICU 50
  74  */
  75 typedef enum UPluralType UPluralType;
  76
  77 /**
  78  * Opaque UPluralRules object for use in C programs.
  79  * @stable ICU 4.8
  80  */
  81 struct UPluralRules;
  82 typedef struct UPluralRules UPluralRules;  /**< C typedef for struct UPluralRules. @stable ICU 4.8 */
  83
  84 /**
  85  * Opens a new UPluralRules object using the predefined cardinal-number plural rules for a
  86  * given locale.
  87  * Same as uplrules_openForType(locale, UPLURAL_TYPE_CARDINAL, status).
  88  * @param locale The locale for which the rules are desired.
  89  * @param status A pointer to a UErrorCode to receive any errors.
  90  * @return A UPluralRules for the specified locale, or NULL if an error occurred.
  91  * @stable ICU 4.8
  92  */
  93 U_CAPI UPluralRules* U_EXPORT2
  94 uplrules_open(const char *locale, UErrorCode *status);
  95
  96 /**
  97  * Opens a new UPluralRules object using the predefined plural rules for a
  98  * given locale and the plural type.
  99  * @param locale The locale for which the rules are desired.
 100  * @param type The plural type (e.g., cardinal or ordinal).
 101  * @param status A pointer to a UErrorCode to receive any errors.
 102  * @return A UPluralRules for the specified locale, or NULL if an error occurred.
 103  * @stable ICU 50
 104  */
 105 U_CAPI UPluralRules* U_EXPORT2
 106 uplrules_openForType(const char *locale, UPluralType type, UErrorCode *status);
 107
 108 /**
 109  * Closes a UPluralRules object. Once closed it may no longer be used.
 110  * @param uplrules The UPluralRules object to close.
 111  * @stable ICU 4.8
 112  */
 113 U_CAPI void U_EXPORT2
 114 uplrules_close(UPluralRules *uplrules);
 115
 116
 117 #if U_SHOW_CPLUSPLUS_API
 118
 119 U_NAMESPACE_BEGIN
 120
 121 /**
 122  * \class LocalUPluralRulesPointer
 123  * "Smart pointer" class, closes a UPluralRules via uplrules_close().
 124  * For most methods see the LocalPointerBase base class.
 125  *
 126  * @see LocalPointerBase
 127  * @see LocalPointer
 128  * @stable ICU 4.8
 129  */
 130 U_DEFINE_LOCAL_OPEN_POINTER(LocalUPluralRulesPointer, UPluralRules, uplrules_close);
 131
 132 U_NAMESPACE_END
 133
 134 #endif // U_SHOW_CPLUSPLUS_API
 135
 136
 137 /**
 138  * Given a floating-point number, returns the keyword of the first rule that
 139  * applies to the number, according to the supplied UPluralRules object.
 140  * @param uplrules The UPluralRules object specifying the rules.
 141  * @param number The number for which the rule has to be determined.
 142  * @param keyword An output buffer to write the keyword of the rule that
 143  *         applies to number.
 144  * @param capacity The capacity of the keyword buffer.
 145  * @param status A pointer to a UErrorCode to receive any errors.
 146  * @return The length of the keyword.
 147  * @stable ICU 4.8
 148  */
 149 U_CAPI int32_t U_EXPORT2
 150 uplrules_select(const UPluralRules *uplrules,
 151                double number,
 152                UChar *keyword, int32_t capacity,
 153                UErrorCode *status);
 154
 155 #ifndef U_HIDE_DRAFT_API
 156 /**
 157  * Given a formatted number, returns the keyword of the first rule
 158  * that applies to the number, according to the supplied UPluralRules object.
 159  *
 160  * A UFormattedNumber allows you to specify an exponent or trailing zeros,
 161  * which can affect the plural category. To get a UFormattedNumber, see
 162  * {@link UNumberFormatter}.
 163  *
 164  * @param uplrules The UPluralRules object specifying the rules.
 165  * @param number The formatted number for which the rule has to be determined.
 166  * @param keyword The destination buffer for the keyword of the rule that
 167  *         applies to number.
 168  * @param capacity The capacity of the keyword buffer.
 169  * @param status A pointer to a UErrorCode to receive any errors.
 170  * @return The length of the keyword.
 171  * @draft ICU 64
 172  */
 173 U_CAPI int32_t U_EXPORT2
 174 uplrules_selectFormatted(const UPluralRules *uplrules,
 175                const struct UFormattedNumber* number,
 176                UChar *keyword, int32_t capacity,
 177                UErrorCode *status);
 178 #endif  /* U_HIDE_DRAFT_API */
 179
 180 #ifndef U_HIDE_INTERNAL_API
 181 /**
 182  * Given a number, returns the keyword of the first rule that applies to the
 183  * number, according to the UPluralRules object and given the number format
 184  * specified by the UNumberFormat object.
 185  * Note: This internal preview interface may be removed in the future if
 186  * an architecturally cleaner solution reaches stable status.
 187  * @param uplrules The UPluralRules object specifying the rules.
 188  * @param number The number for which the rule has to be determined.
 189  * @param fmt The UNumberFormat specifying how the number will be formatted
 190  *        (this can affect the plural form, e.g. "1 dollar" vs "1.0 dollars").
 191  *        If this is NULL, the function behaves like uplrules_select.
 192  * @param keyword An output buffer to write the keyword of the rule that
 193  *         applies to number.
 194  * @param capacity The capacity of the keyword buffer.
 195  * @param status A pointer to a UErrorCode to receive any errors.
 196  * @return The length of keyword.
 197  * @internal ICU 59 technology preview, may be removed in the future
 198  */
 199 U_INTERNAL int32_t U_EXPORT2
 200 uplrules_selectWithFormat(const UPluralRules *uplrules,
 201                           double number,
 202                           const UNumberFormat *fmt,
 203                           UChar *keyword, int32_t capacity,
 204                           UErrorCode *status);
 205
 206 #endif  /* U_HIDE_INTERNAL_API */
 207
 208 /**
 209  * Creates a string enumeration of all plural rule keywords used in this
 210  * UPluralRules object. The rule "other" is always present by default.
 211  * @param uplrules The UPluralRules object specifying the rules for
 212  *        a given locale.
 213  * @param status A pointer to a UErrorCode to receive any errors.
 214  * @return a string enumeration over plural rule keywords, or NULL
 215  * upon error. The caller is responsible for closing the result.
 216  * @stable ICU 59
 217  */
 218 U_STABLE UEnumeration* U_EXPORT2
 219 uplrules_getKeywords(const UPluralRules *uplrules,
 220                      UErrorCode *status);
 221
 222 #endif /* #if !UCONFIG_NO_FORMATTING */
 223
 224 #endif