com.ibm.icu.text

Class UnicodeSetIterator


public 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 UnicodSet, if any.

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

 UnicodeSetIterator it = new UnicodeSetIterator(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 = new UnicodeSetIterator(set);
 while (set.nextRange()) {
   if (set.codepoint != UnicodeSetIterator.IS_STRING) {
     processCodepointRange(set.codepoint, set.codepointEnd);
   } else {
     processString(set.string);
   }
 }
 
Author:
M. Davis

Field Summary

static int
IS_STRING
Value of codepoint if the iterator points to a string.
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 !
protected int
endElement
protected int
nextElement
String
string
If codepoint == IS_STRING, then string points to the current string.

Constructor Summary

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

Method Summary

String
getString()
Gets the current string from the iterator.
protected void
loadRange(int range)
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 set)
Sets this iterator to visit the elements of the given set and resets it to the start of that set.

Field Details

IS_STRING

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

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

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.

endElement

protected int endElement

nextElement

protected int nextElement

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.

Constructor Details

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.

UnicodeSetIterator

public UnicodeSetIterator(UnicodeSet set)
Create an iterator over the given set.
Parameters:
set - set to iterate over

Method Details

getString

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

loadRange

protected void loadRange(int range)

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.

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

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.

reset

public void reset()
Resets this iterator to the start of the set.

reset

public void reset(UnicodeSet set)
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:
set - the set to iterate over.

Copyright (c) 2006 IBM Corporation and others.