1// © 2016 and later: Unicode, Inc. and others.
2// License & terms of use: http://www.unicode.org/copyright.html
3/*
4*******************************************************************************
5*
6* Copyright (C) 2002-2013, International Business Machines
7* Corporation and others. All Rights Reserved.
8*
9*******************************************************************************
10* file name: uenum.h
11* encoding: UTF-8
12* tab size: 8 (not used)
13* indentation:2
14*
15* created on: 2002jul08
16* created by: Vladimir Weinstein
17*/
18
19#ifndef __UENUM_H
20#define __UENUM_H
21
22#include "unicode/utypes.h"
23#include "unicode/localpointer.h"
24
25#if U_SHOW_CPLUSPLUS_API
26U_NAMESPACE_BEGIN
27class StringEnumeration;
28U_NAMESPACE_END
29#endif
30
31/**
32 * \file
33 * \brief C API: String Enumeration
34 */
35
36/**
37 * An enumeration object.
38 * For usage in C programs.
39 * @stable ICU 2.2
40 */
41struct UEnumeration;
42/** structure representing an enumeration object instance @stable ICU 2.2 */
43typedef struct UEnumeration UEnumeration;
44
45/**
46 * Disposes of resources in use by the iterator. If en is NULL,
47 * does nothing. After this call, any char* or UChar* pointer
48 * returned by uenum_unext() or uenum_next() is invalid.
49 * @param en UEnumeration structure pointer
50 * @stable ICU 2.2
51 */
52U_STABLE void U_EXPORT2
53uenum_close(UEnumeration* en);
54
55#if U_SHOW_CPLUSPLUS_API
56
57U_NAMESPACE_BEGIN
58
59/**
60 * \class LocalUEnumerationPointer
61 * "Smart pointer" class, closes a UEnumeration via uenum_close().
62 * For most methods see the LocalPointerBase base class.
63 *
64 * @see LocalPointerBase
65 * @see LocalPointer
66 * @stable ICU 4.4
67 */
68U_DEFINE_LOCAL_OPEN_POINTER(LocalUEnumerationPointer, UEnumeration, uenum_close);
69
70U_NAMESPACE_END
71
72#endif
73
74/**
75 * Returns the number of elements that the iterator traverses. If
76 * the iterator is out-of-sync with its service, status is set to
77 * U_ENUM_OUT_OF_SYNC_ERROR.
78 * This is a convenience function. It can end up being very
79 * expensive as all the items might have to be pre-fetched (depending
80 * on the type of data being traversed). Use with caution and only
81 * when necessary.
82 * @param en UEnumeration structure pointer
83 * @param status error code, can be U_ENUM_OUT_OF_SYNC_ERROR if the
84 * iterator is out of sync.
85 * @return number of elements in the iterator
86 * @stable ICU 2.2
87 */
88U_STABLE int32_t U_EXPORT2
89uenum_count(UEnumeration* en, UErrorCode* status);
90
91/**
92 * Returns the next element in the iterator's list. If there are
93 * no more elements, returns NULL. If the iterator is out-of-sync
94 * with its service, status is set to U_ENUM_OUT_OF_SYNC_ERROR and
95 * NULL is returned. If the native service string is a char* string,
96 * it is converted to UChar* with the invariant converter.
97 * The result is terminated by (UChar)0.
98 * @param en the iterator object
99 * @param resultLength pointer to receive the length of the result
100 * (not including the terminating \\0).
101 * If the pointer is NULL it is ignored.
102 * @param status the error code, set to U_ENUM_OUT_OF_SYNC_ERROR if
103 * the iterator is out of sync with its service.
104 * @return a pointer to the string. The string will be
105 * zero-terminated. The return pointer is owned by this iterator
106 * and must not be deleted by the caller. The pointer is valid
107 * until the next call to any uenum_... method, including
108 * uenum_next() or uenum_unext(). When all strings have been
109 * traversed, returns NULL.
110 * @stable ICU 2.2
111 */
112U_STABLE const UChar* U_EXPORT2
113uenum_unext(UEnumeration* en,
114 int32_t* resultLength,
115 UErrorCode* status);
116
117/**
118 * Returns the next element in the iterator's list. If there are
119 * no more elements, returns NULL. If the iterator is out-of-sync
120 * with its service, status is set to U_ENUM_OUT_OF_SYNC_ERROR and
121 * NULL is returned. If the native service string is a UChar*
122 * string, it is converted to char* with the invariant converter.
123 * The result is terminated by (char)0. If the conversion fails
124 * (because a character cannot be converted) then status is set to
125 * U_INVARIANT_CONVERSION_ERROR and the return value is undefined
126 * (but non-NULL).
127 * @param en the iterator object
128 * @param resultLength pointer to receive the length of the result
129 * (not including the terminating \\0).
130 * If the pointer is NULL it is ignored.
131 * @param status the error code, set to U_ENUM_OUT_OF_SYNC_ERROR if
132 * the iterator is out of sync with its service. Set to
133 * U_INVARIANT_CONVERSION_ERROR if the underlying native string is
134 * UChar* and conversion to char* with the invariant converter
135 * fails. This error pertains only to current string, so iteration
136 * might be able to continue successfully.
137 * @return a pointer to the string. The string will be
138 * zero-terminated. The return pointer is owned by this iterator
139 * and must not be deleted by the caller. The pointer is valid
140 * until the next call to any uenum_... method, including
141 * uenum_next() or uenum_unext(). When all strings have been
142 * traversed, returns NULL.
143 * @stable ICU 2.2
144 */
145U_STABLE const char* U_EXPORT2
146uenum_next(UEnumeration* en,
147 int32_t* resultLength,
148 UErrorCode* status);
149
150/**
151 * Resets the iterator to the current list of service IDs. This
152 * re-establishes sync with the service and rewinds the iterator
153 * to start at the first element.
154 * @param en the iterator object
155 * @param status the error code, set to U_ENUM_OUT_OF_SYNC_ERROR if
156 * the iterator is out of sync with its service.
157 * @stable ICU 2.2
158 */
159U_STABLE void U_EXPORT2
160uenum_reset(UEnumeration* en, UErrorCode* status);
161
162#if U_SHOW_CPLUSPLUS_API
163
164/**
165 * Given a StringEnumeration, wrap it in a UEnumeration. The
166 * StringEnumeration is adopted; after this call, the caller must not
167 * delete it (regardless of error status).
168 * @param adopted the C++ StringEnumeration to be wrapped in a UEnumeration.
169 * @param ec the error code.
170 * @return a UEnumeration wrapping the adopted StringEnumeration.
171 * @stable ICU 4.2
172 */
173U_STABLE UEnumeration* U_EXPORT2
174uenum_openFromStringEnumeration(icu::StringEnumeration* adopted, UErrorCode* ec);
175
176#endif
177
178/**
179 * Given an array of const UChar* strings, return a UEnumeration. String pointers from 0..count-1 must not be null.
180 * Do not free or modify either the string array or the characters it points to until this object has been destroyed with uenum_close.
181 * \snippet test/cintltst/uenumtst.c uenum_openUCharStringsEnumeration
182 * @param strings array of const UChar* strings (each null terminated). All storage is owned by the caller.
183 * @param count length of the array
184 * @param ec error code
185 * @return the new UEnumeration object. Caller is responsible for calling uenum_close to free memory.
186 * @see uenum_close
187 * @stable ICU 50
188 */
189U_STABLE UEnumeration* U_EXPORT2
190uenum_openUCharStringsEnumeration(const UChar* const strings[], int32_t count,
191 UErrorCode* ec);
192
193/* Note: next function is not hidden as draft, as it is used internally (it was formerly an internal function). */
194
195/**
196 * Given an array of const char* strings (invariant chars only), return a UEnumeration. String pointers from 0..count-1 must not be null.
197 * Do not free or modify either the string array or the characters it points to until this object has been destroyed with uenum_close.
198 * \snippet test/cintltst/uenumtst.c uenum_openCharStringsEnumeration
199 * @param strings array of char* strings (each null terminated). All storage is owned by the caller.
200 * @param count length of the array
201 * @param ec error code
202 * @return the new UEnumeration object. Caller is responsible for calling uenum_close to free memory
203 * @see uenum_close
204 * @stable ICU 50
205 */
206U_STABLE UEnumeration* U_EXPORT2
207uenum_openCharStringsEnumeration(const char* const strings[], int32_t count,
208 UErrorCode* ec);
209
210#endif
211