/*
*******************************************************************************
*
-* Copyright (C) 2002, International Business Machines
+* Copyright (C) 2002-2007, International Business Machines
* Corporation and others. All Rights Reserved.
*
*******************************************************************************
#define STRENUM_H
#include "unicode/uobject.h"
+#include "unicode/unistr.h"
+/**
+ * \file
+ * \brief C++ API: String Enumeration
+ */
+
U_NAMESPACE_BEGIN
-class UnicodeString;
-
/**
* Base class for 'pure' C++ implementations of uenum api. Adds a
* method that returns the next UnicodeString since in C++ this can
* upon any subsequent call to the enumeration's destructor, next,
* unext, snext, or reset.</p>
*
- * @draft ICU 2.4
+ * ICU 2.8 adds some default implementations and helper functions
+ * for subclasses.
+ *
+ * @stable ICU 2.4
*/
class U_COMMON_API StringEnumeration : public UObject {
- public:
- /**
- * Destructor.
- * @draft ICU 2.4
- */
- virtual ~StringEnumeration();
-
- /**
- * <p>Return 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, and the return value is zero.</p>
- *
- * <p>The return value will not change except possibly as a result of
- * a subsequent call to reset, or if the iterator becomes out of sync.</p>
- *
- * <p>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 storage format of the data being
- * traversed).</p>
- *
- * @param status the error code.
- * @return number of elements in the iterator.
- *
- * @draft ICU 2.4 */
- virtual int32_t count(UErrorCode& status) const = 0;
-
- /**
- * <p>Returns the next element as a NUL-terminated char*. If there
- * are no more elements, returns NULL. If the resultLength pointer
- * is not NULL, the length of the string (not counting the
- * terminating NUL) is returned at that address. If an error
- * status is returned, the value at resultLength is undefined.</p>
- *
- * <p>The returned pointer is owned by this iterator and must not be
- * deleted by the caller. The pointer is valid until the next call
- * to next, unext, snext, reset, or the enumerator's destructor.</p>
- *
- * <p>If the iterator is out of sync with its service, status is set
- * to U_ENUM_OUT_OF_SYNC_ERROR and NULL is returned.</p>
- *
- * <p>If the native service string is a UChar* string, it is
- * converted to char* with the invariant converter. 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 (though not NULL).</p>
- *
- * @param status the error code.
- * @param resultLength a pointer to receive the length, can be NULL.
- * @return a pointer to the string, or NULL.
- *
- * @draft ICU 2.4
- */
- virtual const char* next(int32_t *resultLength, UErrorCode& status) = 0;
-
- /**
- * <p>Returns the next element as a NUL-terminated UChar*. If there
- * are no more elements, returns NULL. If the resultLength pointer
- * is not NULL, the length of the string (not counting the
- * terminating NUL) is returned at that address. If an error
- * status is returned, the value at resultLength is undefined.</p>
- *
- * <p>The returned pointer is owned by this iterator and must not be
- * deleted by the caller. The pointer is valid until the next call
- * to next, unext, snext, reset, or the enumerator's destructor.</p>
- *
- * <p>If the iterator is out of sync with its service, status is set
- * to U_ENUM_OUT_OF_SYNC_ERROR and NULL is returned.</p>
- *
- * @param status the error code.
- * @param resultLength a ponter to receive the length, can be NULL.
- * @return a pointer to the string, or NULL.
- *
- * @draft ICU 2.4
- */
- virtual const UChar* unext(int32_t *resultLength, UErrorCode& status) = 0;
-
- /**
- * <p>Returns the next element a UnicodeString*. If there are no
- * more elements, returns NULL.</p>
- *
- * <p>The returned pointer is owned by this iterator and must not be
- * deleted by the caller. The pointer is valid until the next call
- * to next, unext, snext, reset, or the enumerator's destructor.</p>
- *
- * <p>If the iterator is out of sync with its service, status is set
- * to U_ENUM_OUT_OF_SYNC_ERROR and NULL is returned.</p>
- *
- * @param status the error code.
- * @return a pointer to the string, or NULL.
- *
- * @draft ICU 2.4
- */
- virtual const UnicodeString* snext(UErrorCode& status) = 0;
-
- /**
- * <p>Resets the iterator. This re-establishes sync with the
- * service and rewinds the iterator to start at the first
- * element.</p>
- *
- * <p>Previous pointers returned by next, unext, or snext become
- * invalid, and the value returned by count might change.</p>
- *
- * @param status the error code.
- *
- * @draft ICU 2.4
- */
- virtual void reset(UErrorCode& status) = 0;
-};
+public:
+ /**
+ * Destructor.
+ * @stable ICU 2.4
+ */
+ virtual ~StringEnumeration();
+
+ /**
+ * Clone this object, an instance of a subclass of StringEnumeration.
+ * Clones can be used concurrently in multiple threads.
+ * If a subclass does not implement clone(), or if an error occurs,
+ * then NULL is returned.
+ * The clone functions in all subclasses return a base class pointer
+ * because some compilers do not support covariant (same-as-this)
+ * return types; cast to the appropriate subclass if necessary.
+ * The caller must delete the clone.
+ *
+ * @return a clone of this object
+ *
+ * @see getDynamicClassID
+ * @stable ICU 2.8
+ */
+ virtual StringEnumeration *clone() const;
+
+ /**
+ * <p>Return 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, and the return value is zero.</p>
+ *
+ * <p>The return value will not change except possibly as a result of
+ * a subsequent call to reset, or if the iterator becomes out of sync.</p>
+ *
+ * <p>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 storage format of the data being
+ * traversed).</p>
+ *
+ * @param status the error code.
+ * @return number of elements in the iterator.
+ *
+ * @stable ICU 2.4 */
+ virtual int32_t count(UErrorCode& status) const = 0;
+
+ /**
+ * <p>Returns the next element as a NUL-terminated char*. If there
+ * are no more elements, returns NULL. If the resultLength pointer
+ * is not NULL, the length of the string (not counting the
+ * terminating NUL) is returned at that address. If an error
+ * status is returned, the value at resultLength is undefined.</p>
+ *
+ * <p>The returned pointer is owned by this iterator and must not be
+ * deleted by the caller. The pointer is valid until the next call
+ * to next, unext, snext, reset, or the enumerator's destructor.</p>
+ *
+ * <p>If the iterator is out of sync with its service, status is set
+ * to U_ENUM_OUT_OF_SYNC_ERROR and NULL is returned.</p>
+ *
+ * <p>If the native service string is a UChar* string, it is
+ * converted to char* with the invariant converter. 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 (though not NULL).</p>
+ *
+ * Starting with ICU 2.8, the default implementation calls snext()
+ * and handles the conversion.
+ *
+ * @param status the error code.
+ * @param resultLength a pointer to receive the length, can be NULL.
+ * @return a pointer to the string, or NULL.
+ *
+ * @stable ICU 2.4
+ */
+ virtual const char* next(int32_t *resultLength, UErrorCode& status);
-inline StringEnumeration::~StringEnumeration() {
-}
+ /**
+ * <p>Returns the next element as a NUL-terminated UChar*. If there
+ * are no more elements, returns NULL. If the resultLength pointer
+ * is not NULL, the length of the string (not counting the
+ * terminating NUL) is returned at that address. If an error
+ * status is returned, the value at resultLength is undefined.</p>
+ *
+ * <p>The returned pointer is owned by this iterator and must not be
+ * deleted by the caller. The pointer is valid until the next call
+ * to next, unext, snext, reset, or the enumerator's destructor.</p>
+ *
+ * <p>If the iterator is out of sync with its service, status is set
+ * to U_ENUM_OUT_OF_SYNC_ERROR and NULL is returned.</p>
+ *
+ * Starting with ICU 2.8, the default implementation calls snext()
+ * and handles the conversion.
+ *
+ * @param status the error code.
+ * @param resultLength a ponter to receive the length, can be NULL.
+ * @return a pointer to the string, or NULL.
+ *
+ * @stable ICU 2.4
+ */
+ virtual const UChar* unext(int32_t *resultLength, UErrorCode& status);
+
+ /**
+ * <p>Returns the next element a UnicodeString*. If there are no
+ * more elements, returns NULL.</p>
+ *
+ * <p>The returned pointer is owned by this iterator and must not be
+ * deleted by the caller. The pointer is valid until the next call
+ * to next, unext, snext, reset, or the enumerator's destructor.</p>
+ *
+ * <p>If the iterator is out of sync with its service, status is set
+ * to U_ENUM_OUT_OF_SYNC_ERROR and NULL is returned.</p>
+ *
+ * @param status the error code.
+ * @return a pointer to the string, or NULL.
+ *
+ * @stable ICU 2.4
+ */
+ virtual const UnicodeString* snext(UErrorCode& status) = 0;
+
+ /**
+ * <p>Resets the iterator. This re-establishes sync with the
+ * service and rewinds the iterator to start at the first
+ * element.</p>
+ *
+ * <p>Previous pointers returned by next, unext, or snext become
+ * invalid, and the value returned by count might change.</p>
+ *
+ * @param status the error code.
+ *
+ * @stable ICU 2.4
+ */
+ virtual void reset(UErrorCode& status) = 0;
+
+ /**
+ * Compares this enumeration to other to check if both are equal
+ *
+ * @param that The other string enumeration to compare this object to
+ * @return TRUE if the enumerations are equal. FALSE if not.
+ * @stable ICU 3.6
+ */
+ virtual UBool operator==(const StringEnumeration& that)const;
+ /**
+ * Compares this enumeration to other to check if both are not equal
+ *
+ * @param that The other string enumeration to compare this object to
+ * @return TRUE if the enumerations are equal. FALSE if not.
+ * @stable ICU 3.6
+ */
+ virtual UBool operator!=(const StringEnumeration& that)const;
+
+protected:
+ /**
+ * UnicodeString field for use with default implementations and subclasses.
+ * @stable ICU 2.8
+ */
+ UnicodeString unistr;
+ /**
+ * char * default buffer for use with default implementations and subclasses.
+ * @stable ICU 2.8
+ */
+ char charsBuffer[32];
+ /**
+ * char * buffer for use with default implementations and subclasses.
+ * Allocated in constructor and in ensureCharsCapacity().
+ * @stable ICU 2.8
+ */
+ char *chars;
+ /**
+ * Capacity of chars, for use with default implementations and subclasses.
+ * @stable ICU 2.8
+ */
+ int32_t charsCapacity;
+
+ /**
+ * Default constructor for use with default implementations and subclasses.
+ * @stable ICU 2.8
+ */
+ StringEnumeration();
+
+ /**
+ * Ensures that chars is at least as large as the requested capacity.
+ * For use with default implementations and subclasses.
+ *
+ * @param capacity Requested capacity.
+ * @param status ICU in/out error code.
+ * @stable ICU 2.8
+ */
+ void ensureCharsCapacity(int32_t capacity, UErrorCode &status);
+
+ /**
+ * Converts s to Unicode and sets unistr to the result.
+ * For use with default implementations and subclasses,
+ * especially for implementations of snext() in terms of next().
+ * This is provided with a helper function instead of a default implementation
+ * of snext() to avoid potential infinite loops between next() and snext().
+ *
+ * For example:
+ * \code
+ * const UnicodeString* snext(UErrorCode& status) {
+ * int32_t resultLength=0;
+ * const char *s=next(&resultLength, status);
+ * return setChars(s, resultLength, status);
+ * }
+ * \endcode
+ *
+ * @param s String to be converted to Unicode.
+ * @param length Length of the string.
+ * @param status ICU in/out error code.
+ * @return A pointer to unistr.
+ * @stable ICU 2.8
+ */
+ UnicodeString *setChars(const char *s, int32_t length, UErrorCode &status);
+};
U_NAMESPACE_END
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