1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 *****************************************************************************************
5 * Copyright (C) 2013-2014, International Business Machines
6 * Corporation and others. All Rights Reserved.
7 *****************************************************************************************
8 */
9 
10 #ifndef UNUMSYS_H
11 #define UNUMSYS_H
12 
13 #include "unicode/utypes.h"
14 
15 #if !UCONFIG_NO_FORMATTING
16 
17 #include "unicode/uenum.h"
18 
19 #if U_SHOW_CPLUSPLUS_API
20 #include "unicode/localpointer.h"
21 #endif   // U_SHOW_CPLUSPLUS_API
22 
23 /**
24  * \file
25  * \brief C API: UNumberingSystem, information about numbering systems
26  *
27  * Defines numbering systems. A numbering system describes the scheme by which
28  * numbers are to be presented to the end user. In its simplest form, a numbering
29  * system describes the set of digit characters that are to be used to display
30  * numbers, such as Western digits, Thai digits, Arabic-Indic digits, etc., in a
31  * positional numbering system with a specified radix (typically 10).
32  * More complicated numbering systems are algorithmic in nature, and require use
33  * of an RBNF formatter (rule based number formatter), in order to calculate
34  * the characters to be displayed for a given number. Examples of algorithmic
35  * numbering systems include Roman numerals, Chinese numerals, and Hebrew numerals.
36  * Formatting rules for many commonly used numbering systems are included in
37  * the ICU package, based on the numbering system rules defined in CLDR.
38  * Alternate numbering systems can be specified to a locale by using the
39  * numbers locale keyword.
40  */
41 
42 /**
43  * Opaque UNumberingSystem object for use in C programs.
44  * @stable ICU 52
45  */
46 struct UNumberingSystem;
47 typedef struct UNumberingSystem UNumberingSystem;  /**< C typedef for struct UNumberingSystem. @stable ICU 52 */
48 
49 /**
50  * Opens a UNumberingSystem object using the default numbering system for the specified
51  * locale.
52  * @param locale    The locale for which the default numbering system should be opened.
53  * @param status    A pointer to a UErrorCode to receive any errors. For example, this
54  *                  may be U_UNSUPPORTED_ERROR for a locale such as "en@numbers=xyz" that
55  *                  specifies a numbering system unknown to ICU.
56  * @return          A UNumberingSystem for the specified locale, or NULL if an error
57  *                  occurred.
58  * @stable ICU 52
59  */
60 U_CAPI UNumberingSystem * U_EXPORT2
61 unumsys_open(const char *locale, UErrorCode *status);
62 
63 /**
64  * Opens a UNumberingSystem object using the name of one of the predefined numbering
65  * systems specified by CLDR and known to ICU, such as "latn", "arabext", or "hanidec";
66  * the full list is returned by unumsys_openAvailableNames. Note that some of the names
67  * listed at http://unicode.org/repos/cldr/tags/latest/common/bcp47/number.xml - e.g.
68  * default, native, traditional, finance - do not identify specific numbering systems,
69  * but rather key values that may only be used as part of a locale, which in turn
70  * defines how they are mapped to a specific numbering system such as "latn" or "hant".
71  *
72  * @param name      The name of the numbering system for which a UNumberingSystem object
73  *                  should be opened.
74  * @param status    A pointer to a UErrorCode to receive any errors. For example, this
75  *                  may be U_UNSUPPORTED_ERROR for a numbering system such as "xyz" that
76  *                  is unknown to ICU.
77  * @return          A UNumberingSystem for the specified name, or NULL if an error
78  *                  occurred.
79  * @stable ICU 52
80  */
81 U_CAPI UNumberingSystem * U_EXPORT2
82 unumsys_openByName(const char *name, UErrorCode *status);
83 
84 /**
85  * Close a UNumberingSystem object. Once closed it may no longer be used.
86  * @param unumsys   The UNumberingSystem object to close.
87  * @stable ICU 52
88  */
89 U_CAPI void U_EXPORT2
90 unumsys_close(UNumberingSystem *unumsys);
91 
92 #if U_SHOW_CPLUSPLUS_API
93 U_NAMESPACE_BEGIN
94 
95 /**
96  * \class LocalUNumberingSystemPointer
97  * "Smart pointer" class, closes a UNumberingSystem via unumsys_close().
98  * For most methods see the LocalPointerBase base class.
99  * @see LocalPointerBase
100  * @see LocalPointer
101  * @stable ICU 52
102  */
103 U_DEFINE_LOCAL_OPEN_POINTER(LocalUNumberingSystemPointer, UNumberingSystem, unumsys_close);
104 
105 U_NAMESPACE_END
106 #endif
107 
108 /**
109  * Returns an enumeration over the names of all of the predefined numbering systems known
110  * to ICU.
111  * The numbering system names will be in alphabetical (invariant) order.
112  * @param status    A pointer to a UErrorCode to receive any errors.
113  * @return          A pointer to a UEnumeration that must be closed with uenum_close(),
114  *                  or NULL if an error occurred.
115  * @stable ICU 52
116  */
117 U_CAPI UEnumeration * U_EXPORT2
118 unumsys_openAvailableNames(UErrorCode *status);
119 
120 /**
121  * Returns the name of the specified UNumberingSystem object (if it is one of the
122  * predefined names known to ICU).
123  * @param unumsys   The UNumberingSystem whose name is desired.
124  * @return          A pointer to the name of the specified UNumberingSystem object, or
125  *                  NULL if the name is not one of the ICU predefined names. The pointer
126  *                  is only valid for the lifetime of the UNumberingSystem object.
127  * @stable ICU 52
128  */
129 U_CAPI const char * U_EXPORT2
130 unumsys_getName(const UNumberingSystem *unumsys);
131 
132 /**
133  * Returns whether the given UNumberingSystem object is for an algorithmic (not purely
134  * positional) system.
135  * @param unumsys   The UNumberingSystem whose algorithmic status is desired.
136  * @return          true if the specified UNumberingSystem object is for an algorithmic
137  *                  system.
138  * @stable ICU 52
139  */
140 U_CAPI UBool U_EXPORT2
141 unumsys_isAlgorithmic(const UNumberingSystem *unumsys);
142 
143 /**
144  * Returns the radix of the specified UNumberingSystem object. Simple positional
145  * numbering systems typically have radix 10, but might have a radix of e.g. 16 for
146  * hexadecimal. The radix is less well-defined for non-positional algorithmic systems.
147  * @param unumsys   The UNumberingSystem whose radix is desired.
148  * @return          The radix of the specified UNumberingSystem object.
149  * @stable ICU 52
150  */
151 U_CAPI int32_t U_EXPORT2
152 unumsys_getRadix(const UNumberingSystem *unumsys);
153 
154 /**
155  * Get the description string of the specified UNumberingSystem object. For simple
156  * positional systems this is the ordered string of digits (with length matching
157  * the radix), e.g. "\u3007\u4E00\u4E8C\u4E09\u56DB\u4E94\u516D\u4E03\u516B\u4E5D"
158  * for "hanidec"; it would be "0123456789ABCDEF" for hexadecimal. For
159  * algorithmic systems this is the name of the RBNF ruleset used for formatting,
160  * e.g. "zh/SpelloutRules/%spellout-cardinal" for "hans" or "%greek-upper" for
161  * "grek".
162  * @param unumsys   The UNumberingSystem whose description string is desired.
163  * @param result    A pointer to a buffer to receive the description string.
164  * @param resultLength  The maximum size of result.
165  * @param status    A pointer to a UErrorCode to receive any errors.
166  * @return          The total buffer size needed; if greater than resultLength, the
167  *                  output was truncated.
168  * @stable ICU 52
169  */
170 U_CAPI int32_t U_EXPORT2
171 unumsys_getDescription(const UNumberingSystem *unumsys, UChar *result,
172                        int32_t resultLength, UErrorCode *status);
173 
174 #endif /* #if !UCONFIG_NO_FORMATTING */
175 
176 #endif
177