com.ibm.icu.text

Class UnicodeSetIterator

java.lang.Object

com.ibm.icu.text.UnicodeSetIterator

public final class UnicodeSetIterator
extends Object

UnicodeSetIterator iterates over the contents of a UnicodeSet. It iterates over either code points or code point ranges. After all code points or ranges have been returned, it returns the multicharacter strings of the UnicodeSet, if any.

This class is not intended for public subclassing.

To iterate over code points and multicharacter strings, use a loop like this:

 for (UnicodeSetIterator it = new UnicodeSetIterator(set); it.next();) {
   processString(it.getString());
 }
 

To iterate over code point ranges, use a loop like this:

 for (UnicodeSetIterator it = new UnicodeSetIterator(set); it.nextRange();) {
   if (it.codepoint != UnicodeSetIterator.IS_STRING) {
     processCodepointRange(it.codepoint, it.codepointEnd);
   } else {
     processString(it.getString());
   }
 }
 

To iterate over only the strings, start with new UnicodeSetIterator(set).skipToStrings().

Warning: For speed, UnicodeSet iteration does not check for concurrent modification. Do not alter the UnicodeSet while iterating.

Author:

M. Davis

See Also:

UnicodeSet.ranges(), UnicodeSet.strings(), UnicodeSet.iterator()

Status:

Stable ICU 2.0.

Field Summary

Fields

Modifier and Type	Field and Description
int	codepoint Current code point, or the special value IS_STRING, if the iterator points to a string.
int	codepointEnd When iterating over ranges using nextRange(), codepointEnd contains the inclusive end of the iteration range, if codepoint !
static int	IS_STRING Value of codepoint if the iterator points to a string.
String	string If codepoint == IS_STRING, then string points to the current string.

Constructor Summary

Constructors

Constructor and Description
UnicodeSetIterator() Create an iterator over nothing.
UnicodeSetIterator(UnicodeSet set) Create an iterator over the given set.

Method Summary

Modifier and Type	Method and Description
String	getString() Gets the current string from the iterator.
boolean	next() Returns the next element in the set, either a single code point or a string.
boolean	nextRange() Returns the next element in the set, either a code point range or a string.
void	reset() Resets this iterator to the start of the set.
void	reset(UnicodeSet uset) Sets this iterator to visit the elements of the given set and resets it to the start of that set.
UnicodeSetIterator	skipToStrings() Skips over the remaining code points/ranges, if any.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

IS_STRING

public static final int IS_STRING

Value of codepoint if the iterator points to a string. If codepoint == IS_STRING, then examine string for the current iteration result.

See Also:

Constant Field Values

Status:

Stable ICU 2.0.

codepoint

public int codepoint

Current code point, or the special value IS_STRING, if the iterator points to a string.

Status:

Stable ICU 2.0.

codepointEnd

public int codepointEnd

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.

Status:

Stable ICU 2.0.

string

public String string

If codepoint == IS_STRING, then string points to the current string. If codepoint != IS_STRING, the value of string is undefined.

Status:

Stable ICU 2.0.

Constructor Detail

UnicodeSetIterator

public UnicodeSetIterator(UnicodeSet set)

Create an iterator over the given set.

Parameters:

set - set to iterate over

Status:

Stable ICU 2.0.

UnicodeSetIterator

public UnicodeSetIterator()

Create an iterator over nothing. next() and nextRange() return false. This is a convenience constructor allowing the target to be set later.

Status:

Stable ICU 2.0.

Method Detail

skipToStrings

public UnicodeSetIterator skipToStrings()

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.

Returns:

this

See Also:

UnicodeSet.strings()

Status:

Stable ICU 70.

next

public boolean next()

Returns the next element in the set, either a single code point or a string. If there are no more elements in the set, return false. If codepoint == IS_STRING, the value is a string in the string field. Otherwise the value is a single code point in the codepoint field.

The order of iteration is all code points in sorted order, followed by all strings sorted order. codepointEnd is undefined after calling this method. string is undefined unless codepoint == IS_STRING. Do not mix calls to next() and nextRange() without calling reset() between them. The results of doing so are undefined.

Warning: For speed, UnicodeSet iteration does not check for concurrent modification. Do not alter the UnicodeSet while iterating.

Returns:

true if there was another element in the set and this object contains the element.

Status:

Stable ICU 2.0.

nextRange

public boolean nextRange()

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 codepoint == IS_STRING, the value is a string in the string field. Otherwise the value is a range of one or more code points from codepoint to 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. string is undefined unless codepoint == IS_STRING. Do not mix calls to next() and nextRange() without calling reset() between them. The results of doing so are undefined.

Returns:

true if there was another element in the set and this object contains the element.

Status:

Stable ICU 2.0.

reset

public void reset(UnicodeSet uset)

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.

Parameters:

uset - the set to iterate over.

Status:

Stable ICU 2.0.

reset

public void reset()

Resets this iterator to the start of the set.

Status:

Stable ICU 2.0.

getString

public String getString()

Gets the current string from the iterator. Only use after calling next(), not nextRange().

Status:

Stable ICU 4.0.