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