To iterate over code points and strings, use a loop like this: *
* UnicodeSetIterator it(set);
* while (it.next()) {
* processItem(it.getString());
* }
*
* Each item in the set is accessed as a string. Set elements * consisting of single code points are returned as strings containing * just the one code point. * *
To iterate over code point ranges, instead of individual code points, * use a loop like this: *
* UnicodeSetIterator it(set);
* while (it.nextRange()) {
* if (it.isString()) {
* processString(it.getString());
* } else {
* processCodepointRange(it.getCodepoint(), it.getCodepointEnd());
* }
* }
*
*
* To iterate over only the strings, start with skipToStrings().
*
* @author M. Davis
* @stable ICU 2.4
*/
class U_COMMON_API UnicodeSetIterator U_FINAL : public UObject {
/**
* Value of codepoint if the iterator points to a string.
* If codepoint == IS_STRING, then examine
* string for the current iteration result.
*/
enum { IS_STRING = -1 };
/**
* Current code point, or the special value IS_STRING, if
* the iterator points to a string.
*/
UChar32 codepoint;
/**
* When iterating over ranges using nextRange(),
* codepointEnd contains the inclusive end of the
* iteration range, if codepoint != IS_STRING. If
* iterating over code points using next(), or if
* codepoint == IS_STRING, then the value of
* codepointEnd is undefined.
*/
UChar32 codepointEnd;
/**
* If codepoint == IS_STRING, then string points
* to the current string. If codepoint != IS_STRING, the
* value of string is undefined.
*/
const UnicodeString* string;
public:
/**
* Create an iterator over the given set. The iterator is valid
* only so long as set is valid.
* @param set set to iterate over
* @stable ICU 2.4
*/
UnicodeSetIterator(const UnicodeSet& set);
/**
* Create an iterator over nothing. next() and
* nextRange() return false. This is a convenience
* constructor allowing the target to be set later.
* @stable ICU 2.4
*/
UnicodeSetIterator();
/**
* Destructor.
* @stable ICU 2.4
*/
virtual ~UnicodeSetIterator();
/**
* Returns true if the current element is a string. If so, the
* caller can retrieve it with getString(). If this
* method returns false, the current element is a code point or
* code point range, depending on whether next() or
* nextRange() was called.
* Elements of types string and codepoint can both be retrieved
* with the function getString().
* Elements of type codepoint can also be retrieved with
* getCodepoint().
* For ranges, getCodepoint() returns the starting codepoint
* of the range, and getCodepointEnd() returns the end
* of the range.
* @stable ICU 2.4
*/
inline UBool isString() const;
/**
* Returns the current code point, if isString() returned
* false. Otherwise returns an undefined result.
* @stable ICU 2.4
*/
inline UChar32 getCodepoint() const;
/**
* Returns the end of the current code point range, if
* isString() returned false and nextRange() was
* called. Otherwise returns an undefined result.
* @stable ICU 2.4
*/
inline UChar32 getCodepointEnd() const;
/**
* Returns the current string, if isString() returned
* true. If the current iteration item is a code point, a UnicodeString
* containing that single code point is returned.
*
* Ownership of the returned string remains with the iterator.
* The string is guaranteed to remain valid only until the iterator is
* advanced to the next item, or until the iterator is deleted.
*
* @stable ICU 2.4
*/
const UnicodeString& getString();
#ifndef U_HIDE_DRAFT_API
/**
* Skips over the remaining code points/ranges, if any.
* A following call to next() or nextRange() will yield a string, if there is one.
* No-op if next() would return false, or if it would yield a string anyway.
*
* @return *this
* @draft ICU 70
* @see UnicodeSet#strings()
*/
inline UnicodeSetIterator &skipToStrings() {
// Finish code point/range iteration.
range = endRange;
endElement = -1;
nextElement = 0;
return *this;
}
#endif // U_HIDE_DRAFT_API
/**
* Advances the iteration position to the next element in the set,
* which can be either a single code point or a string.
* If there are no more elements in the set, return false.
*
* * If isString() == true, the value is a * string, otherwise the value is a * single code point. Elements of either type can be retrieved * with the function getString(), while elements of * consisting of a single code point can be retrieved with * getCodepoint() * *
The order of iteration is all code points in sorted order, * followed by all strings sorted order. Do not mix * calls to next() and nextRange() without * calling reset() between them. The results of doing so * are undefined. * * @return true if there was another element in the set. * @stable ICU 2.4 */ UBool next(); /** * Returns the next element in the set, either a code point range * or a string. If there are no more elements in the set, return * false. If isString() == true, the value is a * string and can be accessed with getString(). Otherwise the value is a * range of one or more code points from getCodepoint() to * getCodepointeEnd() inclusive. * *
The order of iteration is all code points ranges in sorted * order, followed by all strings sorted order. Ranges are * disjoint and non-contiguous. The value returned from getString() * is undefined unless isString() == true. Do not mix calls to * next() and nextRange() without calling * reset() between them. The results of doing so are * undefined. * * @return true if there was another element in the set. * @stable ICU 2.4 */ UBool nextRange(); /** * Sets this iterator to visit the elements of the given set and * resets it to the start of that set. The iterator is valid only * so long as set is valid. * @param set the set to iterate over. * @stable ICU 2.4 */ void reset(const UnicodeSet& set); /** * Resets this iterator to the start of the set. * @stable ICU 2.4 */ void reset(); /** * ICU "poor man's RTTI", returns a UClassID for this class. * * @stable ICU 2.4 */ static UClassID U_EXPORT2 getStaticClassID(); /** * ICU "poor man's RTTI", returns a UClassID for the actual class. * * @stable ICU 2.4 */ virtual UClassID getDynamicClassID() const override; // ======================= PRIVATES =========================== private: // endElement and nextElements are really UChar32's, but we keep // them as signed int32_t's so we can do comparisons with // endElement set to -1. Leave them as int32_t's. /** The set */ const UnicodeSet* set; /** End range */ int32_t endRange; /** Range */ int32_t range; /** End element */ int32_t endElement; /** Next element */ int32_t nextElement; /** Next string */ int32_t nextString; /** String count */ int32_t stringCount; /** * Points to the string to use when the caller asks for a * string and the current iteration item is a code point, not a string. */ UnicodeString *cpString; /** Copy constructor. Disallowed. */ UnicodeSetIterator(const UnicodeSetIterator&) = delete; /** Assignment operator. Disallowed. */ UnicodeSetIterator& operator=(const UnicodeSetIterator&) = delete; /** Load range */ void loadRange(int32_t range); }; inline UBool UnicodeSetIterator::isString() const { return codepoint < 0; } inline UChar32 UnicodeSetIterator::getCodepoint() const { return codepoint; } inline UChar32 UnicodeSetIterator::getCodepointEnd() const { return codepointEnd; } U_NAMESPACE_END #endif /* U_SHOW_CPLUSPLUS_API */ #endif