UnicodeSetIterator

public class UnicodeSetIterator
extends Object

java.lang.Object
   ↳ android.icu.text.UnicodeSetIterator


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.

Summary

Fields

public static int IS_STRING

Value of codepoint if the iterator points to a string.

public int codepoint

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

public int codepointEnd

When iterating over ranges using nextRange(), codepointEnd contains the inclusive end of the iteration range, if codepoint != IS_STRING.

public String string

If codepoint == IS_STRING, then string points to the current string.

Public constructors

UnicodeSetIterator(UnicodeSet set)

Create an iterator over the given set.

UnicodeSetIterator()

Create an iterator over nothing.

Public methods

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.

Inherited methods

Fields

IS_STRING

Added in API level 24
public static 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.

codepoint

Added in API level 24
public int codepoint

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

codepointEnd

Added in API level 24
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.

string

Added in API level 24
public String string

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

Public constructors

UnicodeSetIterator

Added in API level 24
public UnicodeSetIterator (UnicodeSet set)

Create an iterator over the given set.

Parameters
set UnicodeSet: set to iterate over

UnicodeSetIterator

Added in API level 24
public UnicodeSetIterator ()

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

Public methods

getString

Added in API level 24
public String getString ()

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

Returns
String

next

Added in API level 24
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
boolean true if there was another element in the set and this object contains the element.

nextRange

Added in API level 24
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
boolean true if there was another element in the set and this object contains the element.

reset

Added in API level 24
public void reset ()

Resets this iterator to the start of the set.

reset

Added in API level 24
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 UnicodeSet: the set to iterate over.

skipToStrings

Added in API level 34
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
UnicodeSetIterator this