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/*
*******************************************************************************
*
* Copyright (C) 2002-2004, International Business Machines
* Corporation and others. All Rights Reserved.
*
*******************************************************************************
* file name: uenum.h
* encoding: US-ASCII
* tab size: 8 (not used)
* indentation:2
*
* created on: 2002jul08
* created by: Vladimir Weinstein
*/
#ifndef __UENUM_H
#define __UENUM_H
#include "unicode/utypes.h"
/**
* An enumeration object.
* For usage in C programs.
* @stable ICU 2.2
*/
struct UEnumeration;
/** structure representing an enumeration object instance @stable ICU 2.2 */
typedef struct UEnumeration UEnumeration;
/**
* Disposes of resources in use by the iterator. If en is NULL,
* does nothing. After this call, any char* or UChar* pointer
* returned by uenum_unext() or uenum_next() is invalid.
* @param en UEnumeration structure pointer
* @stable ICU 2.2
*/
U_STABLE void U_EXPORT2
uenum_close(UEnumeration* en);
/**
* Returns the number of elements that the iterator traverses. If
* the iterator is out-of-sync with its service, status is set to
* U_ENUM_OUT_OF_SYNC_ERROR.
* This is a convenience function. It can end up being very
* expensive as all the items might have to be pre-fetched (depending
* on the type of data being traversed). Use with caution and only
* when necessary.
* @param en UEnumeration structure pointer
* @param status error code, can be U_ENUM_OUT_OF_SYNC_ERROR if the
* iterator is out of sync.
* @return number of elements in the iterator
* @stable ICU 2.2
*/
U_STABLE int32_t U_EXPORT2
uenum_count(UEnumeration* en, UErrorCode* status);
/**
* Returns the next element in the iterator's list. If there are
* no more elements, returns NULL. If the iterator is out-of-sync
* with its service, status is set to U_ENUM_OUT_OF_SYNC_ERROR and
* NULL is returned. If the native service string is a char* string,
* it is converted to UChar* with the invariant converter.
* The result is terminated by (UChar)0.
* @param en the iterator object
* @param resultLength pointer to receive the length of the result
* (not including the terminating \\0).
* If the pointer is NULL it is ignored.
* @param status the error code, set to U_ENUM_OUT_OF_SYNC_ERROR if
* the iterator is out of sync with its service.
* @return a pointer to the string. The string will be
* zero-terminated. The return pointer is owned by this iterator
* and must not be deleted by the caller. The pointer is valid
* until the next call to any uenum_... method, including
* uenum_next() or uenum_unext(). When all strings have been
* traversed, returns NULL.
* @stable ICU 2.2
*/
U_STABLE const UChar* U_EXPORT2
uenum_unext(UEnumeration* en,
int32_t* resultLength,
UErrorCode* status);
/**
* Returns the next element in the iterator's list. If there are
* no more elements, returns NULL. If the iterator is out-of-sync
* with its service, status is set to U_ENUM_OUT_OF_SYNC_ERROR and
* NULL is returned. If the native service string is a UChar*
* string, it is converted to char* with the invariant converter.
* The result is terminated by (char)0. If the conversion fails
* (because a character cannot be converted) then status is set to
* U_INVARIANT_CONVERSION_ERROR and the return value is undefined
* (but non-NULL).
* @param en the iterator object
* @param resultLength pointer to receive the length of the result
* (not including the terminating \\0).
* If the pointer is NULL it is ignored.
* @param status the error code, set to U_ENUM_OUT_OF_SYNC_ERROR if
* the iterator is out of sync with its service. Set to
* U_INVARIANT_CONVERSION_ERROR if the underlying native string is
* UChar* and conversion to char* with the invariant converter
* fails. This error pertains only to current string, so iteration
* might be able to continue successfully.
* @return a pointer to the string. The string will be
* zero-terminated. The return pointer is owned by this iterator
* and must not be deleted by the caller. The pointer is valid
* until the next call to any uenum_... method, including
* uenum_next() or uenum_unext(). When all strings have been
* traversed, returns NULL.
* @stable ICU 2.2
*/
U_STABLE const char* U_EXPORT2
uenum_next(UEnumeration* en,
int32_t* resultLength,
UErrorCode* status);
/**
* Resets the iterator to the current list of service IDs. This
* re-establishes sync with the service and rewinds the iterator
* to start at the first element.
* @param en the iterator object
* @param status the error code, set to U_ENUM_OUT_OF_SYNC_ERROR if
* the iterator is out of sync with its service.
* @stable ICU 2.2
*/
U_STABLE void U_EXPORT2
uenum_reset(UEnumeration* en, UErrorCode* status);
#endif