Back to index...

	/*
	* Copyright (c) 2005, 2011, 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
	* questions.
	*/
	/*
	*******************************************************************************
	* (C) Copyright IBM Corp. and others, 1996-2009 - 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 = 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 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<String> stringIterator = null;

	/**
	* Invariant: stringIterator is null when there are no (more) strings remaining
	*/

	/**
	* @internal
	*/
	protected void loadRange(int aRange) {
	nextElement = set.getRangeStart(aRange);
	endElement = set.getRangeEnd(aRange);
	}
	}

Back to index...