Index: icu46/source/common/unicode/strenum.h |
=================================================================== |
--- icu46/source/common/unicode/strenum.h (revision 0) |
+++ icu46/source/common/unicode/strenum.h (revision 0) |
@@ -0,0 +1,271 @@ |
+/* |
+******************************************************************************* |
+* |
+* Copyright (C) 2002-2007, International Business Machines |
+* Corporation and others. All Rights Reserved. |
+* |
+******************************************************************************* |
+*/ |
+ |
+#ifndef STRENUM_H |
+#define STRENUM_H |
+ |
+#include "unicode/uobject.h" |
+#include "unicode/unistr.h" |
+ |
+/** |
+ * \file |
+ * \brief C++ API: String Enumeration |
+ */ |
+ |
+U_NAMESPACE_BEGIN |
+ |
+/** |
+ * Base class for 'pure' C++ implementations of uenum api. Adds a |
+ * method that returns the next UnicodeString since in C++ this can |
+ * be a common storage format for strings. |
+ * |
+ * <p>The model is that the enumeration is over strings maintained by |
+ * a 'service.' At any point, the service might change, invalidating |
+ * the enumerator (though this is expected to be rare). The iterator |
+ * returns an error if this has occurred. Lack of the error is no |
+ * guarantee that the service didn't change immediately after the |
+ * call, so the returned string still might not be 'valid' on |
+ * subsequent use.</p> |
+ * |
+ * <p>Strings may take the form of const char*, const UChar*, or const |
+ * UnicodeString*. The type you get is determine by the variant of |
+ * 'next' that you call. In general the StringEnumeration is |
+ * optimized for one of these types, but all StringEnumerations can |
+ * return all types. Returned strings are each terminated with a NUL. |
+ * Depending on the service data, they might also include embedded NUL |
+ * characters, so API is provided to optionally return the true |
+ * length, counting the embedded NULs but not counting the terminating |
+ * NUL.</p> |
+ * |
+ * <p>The pointers returned by next, unext, and snext become invalid |
+ * upon any subsequent call to the enumeration's destructor, next, |
+ * unext, snext, or reset.</p> |
+ * |
+ * 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. |
+ * @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); |
+ |
+ /** |
+ * <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 |
+ |
+/* STRENUM_H */ |
+#endif |
Property changes on: icu46/source/common/unicode/strenum.h |
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+ LF |