tec.units.ri.internal.format.l10n.CharacterIterator Maven / Gradle / Ivy
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/*
* Units of Measurement Reference Implementation
* Copyright (c) 2005-2016, Jean-Marie Dautelle, Werner Keil, V2COM.
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions
* and the following disclaimer in the documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of JSR-363 nor the names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package tec.units.ri.internal.format.l10n;
/*
*
* Portions Copyright Copyright 1990-2006, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*/
/*
* (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
* (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved
*
* The original version of this source code and documentation
* is copyrighted and owned by Taligent, Inc., a wholly-owned
* subsidiary of IBM. These materials are provided under terms
* of a License Agreement between Taligent and Sun. This technology
* is protected by multiple US and International patents.
*
* This notice and attribution to Taligent may not be removed.
* Taligent is a registered trademark of Taligent, Inc.
*
*/
/**
* This interface defines a protocol for bidirectional iteration over text. The iterator iterates over a bounded sequence of characters. Characters
* are indexed with values beginning with the value returned by getBeginIndex() and continuing through the value returned by getEndIndex()-1.
*
* Iterators maintain a current character index, whose valid range is from getBeginIndex() to getEndIndex(); the value getEndIndex() is included to
* allow handling of zero-length text ranges and for historical reasons. The current index can be retrieved by calling getIndex() and set directly by
* calling setIndex(), first(), and last().
*
* The methods previous() and next() are used for iteration. They return DONE if they would move outside the range from getBeginIndex() to
* getEndIndex() -1, signaling that the iterator has reached the end of the sequence. DONE is also returned by other methods to indicate that the
* current index is outside this range.
*
*
* Examples:
*
*
* Traverse the text from start to finish
*
*
* public void traverseForward(CharacterIterator iter) {
* for (char c = iter.first(); c != CharacterIterator.DONE; c = iter.next()) {
* processChar(c);
* }
* }
*
*
* Traverse the text backwards, from end to start
*
*
* public void traverseBackward(CharacterIterator iter) {
* for (char c = iter.last(); c != CharacterIterator.DONE; c = iter.previous()) {
* processChar(c);
* }
* }
*
*
* Traverse both forward and backward from a given position in the text. Calls to notBoundary() in this example represents some additional stopping
* criteria.
*
*
* public void traverseOut(CharacterIterator iter, int pos) {
* for (char c = iter.setIndex(pos); c != CharacterIterator.DONE && notBoundary(c); c = iter.next()) {
* }
* int end = iter.getIndex();
* for (char c = iter.setIndex(pos); c != CharacterIterator.DONE && notBoundary(c); c = iter.previous()) {
* }
* int start = iter.getIndex();
* processSection(start, end);
* }
*
*
* @see StringCharacterIterator
* @see AttributedCharacterIterator
*/
interface CharacterIterator {
/**
* Constant that is returned when the iterator has reached either the end or the beginning of the text. The value is '\\uFFFF', the
* "not a character" value which should not occur in any valid Unicode string.
*/
public static final char DONE = '\uFFFF';
/**
* Sets the position to getBeginIndex() and returns the character at that position.
*
* @return the first character in the text, or DONE if the text is empty
* @see #getBeginIndex()
*/
public char first();
/**
* Sets the position to getEndIndex()-1 (getEndIndex() if the text is empty) and returns the character at that position.
*
* @return the last character in the text, or DONE if the text is empty
* @see #getEndIndex()
*/
public char last();
/**
* Gets the character at the current position (as returned by getIndex()).
*
* @return the character at the current position or DONE if the current position is off the end of the text.
* @see #getIndex()
*/
public char current();
/**
* Increments the iterator's index by one and returns the character at the new index. If the resulting index is greater or equal to getEndIndex(),
* the current index is reset to getEndIndex() and a value of DONE is returned.
*
* @return the character at the new position or DONE if the new position is off the end of the text range.
*/
public char next();
/**
* Decrements the iterator's index by one and returns the character at the new index. If the current index is getBeginIndex(), the index remains at
* getBeginIndex() and a value of DONE is returned.
*
* @return the character at the new position or DONE if the current position is equal to getBeginIndex().
*/
public char previous();
/**
* Sets the position to the specified position in the text and returns that character.
*
* @param position
* the position within the text. Valid values range from getBeginIndex() to getEndIndex(). An IllegalArgumentException is thrown if an
* invalid value is supplied.
* @return the character at the specified position or DONE if the specified position is equal to getEndIndex()
*/
public char setIndex(int position);
/**
* Returns the start index of the text.
*
* @return the index at which the text begins.
*/
public int getBeginIndex();
/**
* Returns the end index of the text. This index is the index of the first character following the end of the text.
*
* @return the index after the last character in the text
*/
public int getEndIndex();
/**
* Returns the current index.
*
* @return the current index.
*/
public int getIndex();
}