/*
* Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
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*/
/*
*******************************************************************************
* (C) Copyright IBM Corp. 1996-2005 - All Rights Reserved *
* *
* The original version of this source code and documentation is copyrighted *
* and owned by IBM, These materials are provided under terms of a License *
* Agreement between IBM and Sun. This technology is protected by multiple *
* US and International patents. This notice and attribution to IBM may not *
* to removed. *
*******************************************************************************
*/
package sun.text.normalizer;
import java.util.Iterator;
/**
* 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.
*
* <p>To iterate over code points, use a loop like this:
* <pre>
* UnicodeSetIterator it(set);
* while (set.next()) {
* if (set.codepoint != UnicodeSetIterator::IS_STRING) {
* processCodepoint(set.codepoint);
* } else {
* processString(set.string);
* }
* }
* </pre>
*
* <p>To iterate over code point ranges, use a loop like this:
* <pre>
* UnicodeSetIterator it(set);
* while (set.nextRange()) {
* if (set.codepoint != UnicodeSetIterator::IS_STRING) {
* processCodepointRange(set.codepoint, set.codepointEnd);
* } else {
* processString(set.string);
* }
* }
* </pre>
* @author M. Davis
* @stable ICU 2.0
*/
public class UnicodeSetIterator {
/**
* Value of <tt>codepoint</tt> if the iterator points to a string.
* If <tt>codepoint == IS_STRING</tt>, then examine
* <tt>string</tt> for the current iteration result.
* @stable ICU 2.0
*/
public static int IS_STRING = -1;
/**
* Current code point, or the special value <tt>IS_STRING</tt>, if
* the iterator points to a string.
* @stable ICU 2.0
*/
public int codepoint;
/**
* When iterating over ranges using <tt>nextRange()</tt>,
* <tt>codepointEnd</tt> contains the inclusive end of the
* iteration range, if <tt>codepoint != IS_STRING</tt>. If
* iterating over code points using <tt>next()</tt>, or if
* <tt>codepoint == IS_STRING</tt>, then the value of
* <tt>codepointEnd</tt> is undefined.
* @stable ICU 2.0
*/
public int codepointEnd;
/**
* If <tt>codepoint == IS_STRING</tt>, then <tt>string</tt> points
* to the current string. If <tt>codepoint != IS_STRING</tt>, the
* value of <tt>string</tt> 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 <tt>codepoint == IS_STRING</tt>, the value is a
* string in the <tt>string</tt> field. Otherwise the value is a
* range of one or more code points from <tt>codepoint</tt> to
* <tt>codepointeEnd</tt> inclusive.
*
* <p>The order of iteration is all code points ranges in sorted
* order, followed by all strings sorted order. Ranges are
* disjoint and non-contiguous. <tt>string</tt> is undefined
* unless <tt>codepoint == IS_STRING</tt>. Do not mix calls to
* <tt>next()</tt> and <tt>nextRange()</tt> without calling
* <tt>reset()</tt> 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 = (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 <tt>set</tt> is valid.
* @param set the set to iterate over.
* @stable ICU 2.0
*/
public void reset(UnicodeSet set) {
this.set = set;
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 stringIterator = null;
/**
* Invariant: stringIterator is null when there are no (more) strings remaining
*/
/**
* @internal
*/
protected void loadRange(int range) {
nextElement = set.getRangeStart(range);
endElement = set.getRangeEnd(range);
}
}