uenum.h File Reference

C API: String Enumeration. More...

#include "unicode/utypes.h"
#include "unicode/localpointer.h"
#include "unicode/strenum.h"

Go to the source code of this file.

Namespaces
namespace	icu
	File coll.h.

Typedefs
typedef struct UEnumeration	UEnumeration
	structure representing an enumeration object instance

Functions
void	uenum_close (UEnumeration *en)
	Disposes of resources in use by the iterator.
int32_t	uenum_count (UEnumeration *en, UErrorCode *status)
	Returns the number of elements that the iterator traverses.
const UChar *	uenum_unext (UEnumeration *en, int32_t *resultLength, UErrorCode *status)
	Returns the next element in the iterator's list.
const char *	uenum_next (UEnumeration *en, int32_t *resultLength, UErrorCode *status)
	Returns the next element in the iterator's list.
void	uenum_reset (UEnumeration *en, UErrorCode *status)
	Resets the iterator to the current list of service IDs.
UEnumeration *	uenum_openFromStringEnumeration (icu::StringEnumeration *adopted, UErrorCode *ec)
	Given a StringEnumeration, wrap it in a UEnumeration.
UEnumeration *	uenum_openUCharStringsEnumeration (const UChar *const strings[], int32_t count, UErrorCode *ec)
	Given an array of const UChar* strings, return a UEnumeration.
UEnumeration *	uenum_openCharStringsEnumeration (const char *const strings[], int32_t count, UErrorCode *ec)
	Given an array of const char* strings (invariant chars only), return a UEnumeration.

---

Detailed Description

C API: String Enumeration.

Definition in file uenum.h.

---

Typedef Documentation

typedef struct UEnumeration UEnumeration

structure representing an enumeration object instance

Stable:

ICU 2.2

Definition at line 39 of file uenum.h.

---

Function Documentation

void uenum_close

(

UEnumeration *

en

)

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.

Parameters:

en	UEnumeration structure pointer

Stable:

ICU 2.2

int32_t uenum_count	(	UEnumeration *	en,
		UErrorCode *	status
	)

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.

Parameters:

en	UEnumeration structure pointer
status	error code, can be U_ENUM_OUT_OF_SYNC_ERROR if the iterator is out of sync.

Returns:

number of elements in the iterator

Stable:

ICU 2.2

const char* uenum_next	(	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).

Parameters:

en	the iterator object
resultLength	pointer to receive the length of the result (not including the terminating \0). If the pointer is NULL it is ignored.
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.

Returns:

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

UEnumeration* uenum_openCharStringsEnumeration	(	const char *const	strings[],
		int32_t	count,
		UErrorCode *	ec
	)

Given an array of const char* strings (invariant chars only), return a UEnumeration.

String pointers from 0..count-1 must not be null. Do not free or modify either the string array or the characters it points to until this object has been destroyed with uenum_close.

  const char* strings[] = { "Firstly", "Secondly", "Thirdly", "Fourthly" };
  UEnumeration *u = uenum_openCharStringsEnumeration(strings, 4, &status);

Parameters:

strings	array of char* strings (each null terminated). All storage is owned by the caller.
count	length of the array
ec	error code

Returns:

the new UEnumeration object. Caller is responsible for calling uenum_close to free memory

See also:

uenum_close

Draft:

This API may be changed in the future versions and was introduced in ICU 50

UEnumeration* uenum_openFromStringEnumeration	(	icu::StringEnumeration *	adopted,
		UErrorCode *	ec
	)

Given a StringEnumeration, wrap it in a UEnumeration.

The StringEnumeration is adopted; after this call, the caller must not delete it (regardless of error status).

Parameters:

adopted	the C++ StringEnumeration to be wrapped in a UEnumeration.
ec	the error code.

Returns:

a UEnumeration wrapping the adopted StringEnumeration.

Stable:

ICU 4.2

UEnumeration* uenum_openUCharStringsEnumeration	(	const UChar *const	strings[],
		int32_t	count,
		UErrorCode *	ec
	)

Given an array of const UChar* strings, return a UEnumeration.

String pointers from 0..count-1 must not be null. Do not free or modify either the string array or the characters it points to until this object has been destroyed with uenum_close.

  static const UChar nko_1[] = {0x07c1,0}, nko_2[] = {0x07c2}, nko_3[] = {0x07c3,0}, nko_4[] = {0x07c4,0};
  static const UChar* ustrings[] = {  nko_1, nko_2, nko_3, nko_4  };
  UEnumeration *u = uenum_openUCharStringsEnumeration(ustrings, 4, &status);

Parameters:

strings	array of const UChar* strings (each null terminated). All storage is owned by the caller.
count	length of the array
ec	error code

Returns:

the new UEnumeration object. Caller is responsible for calling uenum_close to free memory.

See also:

uenum_close

Draft:

This API may be changed in the future versions and was introduced in ICU 50

void uenum_reset	(	UEnumeration *	en,
		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.

Parameters:

en	the iterator object
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

const UChar* 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 char* string, it is converted to UChar* with the invariant converter. The result is terminated by (UChar)0.

Parameters:

en	the iterator object
resultLength	pointer to receive the length of the result (not including the terminating \0). If the pointer is NULL it is ignored.
status	the error code, set to U_ENUM_OUT_OF_SYNC_ERROR if the iterator is out of sync with its service.

Returns:

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