To iterate over code points, use a loop like this: *
* UnicodeSetIterator it(set);
* while (set.next()) {
* if (set.codepoint != UnicodeSetIterator::IS_STRING) {
* processCodepoint(set.codepoint);
* } else {
* processString(set.string);
* }
* }
*
*
* To iterate over code point ranges, use a loop like this: *
* UnicodeSetIterator it(set);
* while (set.nextRange()) {
* if (set.codepoint != UnicodeSetIterator::IS_STRING) {
* processCodepointRange(set.codepoint, set.codepointEnd);
* } else {
* processString(set.string);
* }
* }
*
* @author M. Davis
* @stable ICU 2.0
*/
public class UnicodeSetIterator {
/**
* Value of {@code codepoint} if the iterator points to a string.
* If {@code codepoint == IS_STRING}, then examine
* {@code string} for the current iteration result.
* @stable ICU 2.0
*/
public static int IS_STRING = -1;
/**
* Current code point, or the special value {@code IS_STRING}, if
* the iterator points to a string.
* @stable ICU 2.0
*/
public int codepoint;
/**
* When iterating over ranges using {@code nextRange()},
* {@code codepointEnd} contains the inclusive end of the
* iteration range, if {@code codepoint != IS_STRING}. If
* iterating over code points using {@code next()}, or if
* {@code codepoint == IS_STRING}, then the value of
* {@code codepointEnd} is undefined.
* @stable ICU 2.0
*/
public int codepointEnd;
/**
* If {@code codepoint == IS_STRING}, then {@code string} points
* to the current string. If {@code codepoint != IS_STRING}, the
* value of {@code string} is undefined.
* @stable ICU 2.0
*/
public String string;
/**
* Create an iterator over the given set.
* @param set set to iterate over
* @stable ICU 2.0
*/
public UnicodeSetIterator(UnicodeSet set) {
reset(set);
}
/**
* 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 {@code codepoint == IS_STRING}, the value is a
* string in the {@code string} field. Otherwise the value is a
* range of one or more code points from {@code codepoint} to
* {@code codepointeEnd} 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. {@code string} is undefined
* unless {@code codepoint == IS_STRING}. Do not mix calls to
* {@code next()} and {@code nextRange()} without calling
* {@code reset()} between them. The results of doing so are
* undefined.
*
* @return true if there was another element in the set and this
* object contains the element.
* @stable ICU 2.0
*/
public boolean nextRange() {
if (nextElement <= endElement) {
codepointEnd = endElement;
codepoint = nextElement;
nextElement = endElement+1;
return true;
}
if (range < endRange) {
loadRange(++range);
codepointEnd = endElement;
codepoint = nextElement;
nextElement = endElement+1;
return true;
}
// stringIterator == null iff there are no string elements remaining
if (stringIterator == null) return false;
codepoint = IS_STRING; // signal that value is actually a string
string = stringIterator.next();
if (!stringIterator.hasNext()) stringIterator = null;
return true;
}
/**
* 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 {@code set} is valid.
* @param uset the set to iterate over.
* @stable ICU 2.0
*/
public void reset(UnicodeSet uset) {
set = uset;
reset();
}
/**
* Resets this iterator to the start of the set.
* @stable ICU 2.0
*/
public void reset() {
endRange = set.getRangeCount() - 1;
range = 0;
endElement = -1;
nextElement = 0;
if (endRange >= 0) {
loadRange(range);
}
stringIterator = null;
if (set.strings != null) {
stringIterator = set.strings.iterator();
if (!stringIterator.hasNext()) stringIterator = null;
}
}
// ======================= PRIVATES ===========================
private UnicodeSet set;
private int endRange = 0;
private int range = 0;
/**
* @internal
*/
protected int endElement;
/**
* @internal
*/
protected int nextElement;
private Iterator