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
24struct 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 */
53enum 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 */
75typedef enum UPluralType UPluralType;
76
77/**
78 * Opaque UPluralRules object for use in C programs.
79 * @stable ICU 4.8
80 */
81struct UPluralRules;
82typedef 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 */
93U_CAPI UPluralRules* U_EXPORT2
94uplrules_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 */
105U_CAPI UPluralRules* U_EXPORT2
106uplrules_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 */
113U_CAPI void U_EXPORT2
114uplrules_close(UPluralRules *uplrules);
115
116
117#if U_SHOW_CPLUSPLUS_API
118
119U_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 */
130U_DEFINE_LOCAL_OPEN_POINTER(LocalUPluralRulesPointer, UPluralRules, uplrules_close);
131
132U_NAMESPACE_END
133
134#endif
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 */
149U_CAPI int32_t U_EXPORT2
150uplrules_select(const UPluralRules *uplrules,
151 double number,
152 UChar *keyword, int32_t capacity,
153 UErrorCode *status);
154
155/**
156 * Given a formatted number, returns the keyword of the first rule
157 * that applies to the number, according to the supplied UPluralRules object.
158 *
159 * A UFormattedNumber allows you to specify an exponent or trailing zeros,
160 * which can affect the plural category. To get a UFormattedNumber, see
161 * {@link UNumberFormatter}.
162 *
163 * @param uplrules The UPluralRules object specifying the rules.
164 * @param number The formatted number for which the rule has to be determined.
165 * @param keyword The destination buffer for the keyword of the rule that
166 * applies to number.
167 * @param capacity The capacity of the keyword buffer.
168 * @param status A pointer to a UErrorCode to receive any errors.
169 * @return The length of the keyword.
170 * @stable ICU 64
171 */
172U_CAPI int32_t U_EXPORT2
173uplrules_selectFormatted(const UPluralRules *uplrules,
174 const struct UFormattedNumber* number,
175 UChar *keyword, int32_t capacity,
176 UErrorCode *status);
177
178#ifndef U_HIDE_INTERNAL_API
179/**
180 * Given a number, returns the keyword of the first rule that applies to the
181 * number, according to the UPluralRules object and given the number format
182 * specified by the UNumberFormat object.
183 * Note: This internal preview interface may be removed in the future if
184 * an architecturally cleaner solution reaches stable status.
185 * @param uplrules The UPluralRules object specifying the rules.
186 * @param number The number for which the rule has to be determined.
187 * @param fmt The UNumberFormat specifying how the number will be formatted
188 * (this can affect the plural form, e.g. "1 dollar" vs "1.0 dollars").
189 * If this is NULL, the function behaves like uplrules_select.
190 * @param keyword An output buffer to write the keyword of the rule that
191 * applies to number.
192 * @param capacity The capacity of the keyword buffer.
193 * @param status A pointer to a UErrorCode to receive any errors.
194 * @return The length of keyword.
195 * @internal ICU 59 technology preview, may be removed in the future
196 */
197U_INTERNAL int32_t U_EXPORT2
198uplrules_selectWithFormat(const UPluralRules *uplrules,
199 double number,
200 const UNumberFormat *fmt,
201 UChar *keyword, int32_t capacity,
202 UErrorCode *status);
203
204#endif /* U_HIDE_INTERNAL_API */
205
206/**
207 * Creates a string enumeration of all plural rule keywords used in this
208 * UPluralRules object. The rule "other" is always present by default.
209 * @param uplrules The UPluralRules object specifying the rules for
210 * a given locale.
211 * @param status A pointer to a UErrorCode to receive any errors.
212 * @return a string enumeration over plural rule keywords, or NULL
213 * upon error. The caller is responsible for closing the result.
214 * @stable ICU 59
215 */
216U_STABLE UEnumeration* U_EXPORT2
217uplrules_getKeywords(const UPluralRules *uplrules,
218 UErrorCode *status);
219
220#endif /* #if !UCONFIG_NO_FORMATTING */
221
222#endif
223