diff options
Diffstat (limited to 'libjava/java/text/StringCharacterIterator.java')
| -rw-r--r-- | libjava/java/text/StringCharacterIterator.java | 360 |
1 files changed, 278 insertions, 82 deletions
diff --git a/libjava/java/text/StringCharacterIterator.java b/libjava/java/text/StringCharacterIterator.java index 487b09c8220..64af2601df8 100644 --- a/libjava/java/text/StringCharacterIterator.java +++ b/libjava/java/text/StringCharacterIterator.java @@ -1,149 +1,345 @@ -// StringCharacterIterator.java - Iterate over string of Unicode characters. +/* StringCharacterIterator.java -- Iterate over a character range in a string + Copyright (C) 1998, 1999, 2001 Free Software Foundation, Inc. -/* Copyright (C) 1999, 2000 Free Software Foundation +This file is part of GNU Classpath. - This file is part of libgcj. +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA +02111-1307 USA. + +As a special exception, if you link this library with other files to +produce an executable, this library does not by itself cause the +resulting executable to be covered by the GNU General Public License. +This exception does not however invalidate any other reasons why the +executable file might be covered by the GNU General Public License. */ -This software is copyrighted work licensed under the terms of the -Libgcj License. Please consult the file "LIBGCJ_LICENSE" for -details. */ package java.text; /** + * This class iterates over a range of characters in a <code>String</code>. + * For a given range of text, a beginning and ending index, + * as well as a current index are defined. These values can be queried + * by the methods in this interface. Additionally, various methods allow + * the index to be set. + * + * @author Aaron M. Renn (arenn@urbanophile.com) * @author Tom Tromey <tromey@cygnus.com> - * @date February 22, 1999 - */ -/* Written using "Java Class Libraries", 2nd edition, plus online - * API docs for JDK 1.2 beta from http://www.javasoft.com. - * Status: Believed complete and correct to 1.1. */ - public final class StringCharacterIterator implements CharacterIterator { - public Object clone () + /** + * This is the string to iterate over + */ + private String text; + + /** + * This is the value of the start position of the text range. + */ + private int begin; + + /** + * This is the value of the ending position of the text range. + */ + private int end; + + /** + * This is the current value of the scan index. + */ + private int index; + + /** + * This method initializes a new instance of + * <code>StringCharacterIterator</code> to iterate over the entire + * text of the specified <code>String</code>. The initial index + * value will be set to the first character in the string. + * + * @param text The <code>String</code> to iterate through. + */ + public StringCharacterIterator (String text) { - return (Object) new StringCharacterIterator (text, begin, end, pos); + this (text, 0, text.length (), 0); } - public char current () + /*************************************************************************/ + + /** + * This method initializes a new instance of + * <code>StringCharacterIterator</code> to iterate over the entire + * text of the specified <code>String</code>. The initial index + * value will be set to the specified value. + * + * @param text The <code>String</code> to iterate through. + * @param index The initial index position. + */ + public StringCharacterIterator (String text, int index) { - // This follows JDK 1.2 semantics and not 1.1 semantics. - // In 1.1 we would throw an exception if begin==end. - return (pos < end) ? text.charAt(pos) : CharacterIterator.DONE; + this (text, 0, text.length (), index); } - public boolean equals (Object obj) + /*************************************************************************/ + + /** + * This method initializes a new instance of + * <code>StringCharacterIterator</code> that iterates over the text + * in a subrange of the specified <code>String</code>. The + * beginning and end of the range are specified by the caller, as is + * the initial index position. + * + * @param text The <code>String</code> to iterate through. + * @param begin The beginning position in the character range. + * @param end The ending position in the character range. + * @param index The initial index position. + * + * @param IllegalArgumentException If any of the range values are + * invalid. + */ + public StringCharacterIterator (String text, int begin, int end, int index) { - if (! (obj instanceof StringCharacterIterator)) - return false; - StringCharacterIterator sci = (StringCharacterIterator) obj; - // The spec says "the same text". We take this to mean equals, - // not ==. - return (pos == sci.pos - && begin == sci.begin - && end == sci.end - && text.equals(sci.text)); + int len = text.length (); + + if ((begin < 0) || (begin > len)) + throw new IllegalArgumentException ("Bad begin position"); + + if ((end < begin) || (end > len)) + throw new IllegalArgumentException ("Bad end position"); + + if ((index < begin) || (index > end)) + throw new IllegalArgumentException ("Bad initial index position"); + + this.text = text; + this.begin = begin; + this.end = end; + this.index = index; } - public char first () + /** + * This is a package level constructor that copies the text out of + * an existing StringCharacterIterator and resets the beginning and + * ending index. + * + * @param scci The StringCharacterIterator to copy the info from + * @param begin The beginning index of the range we are interested in. + * @param end The ending index of the range we are interested in. + */ + StringCharacterIterator (StringCharacterIterator sci, int begin, int end) { - pos = begin; - return current (); + this (sci.text, begin, end, begin); } - public int getBeginIndex () + /** + * This method returns the character at the current index position + * + * @return The character at the current index position. + */ + public char current () { - return begin; + return (index < end) ? text.charAt (index) : DONE; } - public int getEndIndex () + /*************************************************************************/ + + /** + * This method increments the current index and then returns the + * character at the new index value. If the index is already at + * <code>getEndIndex () - 1</code>, it will not be incremented. + * + * @return The character at the position of the incremented index + * value, or <code>DONE</code> if the index has reached + * getEndIndex () - 1. + */ + public char next () { - return end; + if (index == end) + return DONE; + + ++index; + return current (); } - public int getIndex () + /*************************************************************************/ + + /** + * This method decrements the current index and then returns the + * character at the new index value. If the index value is already + * at the beginning index, it will not be decremented. + * + * @return The character at the position of the decremented index + * value, or <code>DONE</code> if index was already equal to the + * beginning index value. + */ + public char previous () { - return pos; + if (index == begin) + return DONE; + + --index; + return current (); } - public int hashCode () + /*************************************************************************/ + + /** + * This method sets the index value to the beginning of the range and returns + * the character there. + * + * @return The character at the beginning of the range, or + * <code>DONE</code> if the range is empty. + */ + public char first () { - // FIXME: this is a terrible hash code. Find a better one. - return text.hashCode() + pos + begin + end; + index = begin; + return current (); } + /*************************************************************************/ + + /** + * This method sets the index value to <code>getEndIndex () - 1</code> and + * returns the character there. If the range is empty, then the index value + * will be set equal to the beginning index. + * + * @return The character at the end of the range, or + * <code>DONE</code> if the range is empty. + */ public char last () { - pos = end; + if (end == begin) + return DONE; + + index = end - 1; return current (); } - public char next () + /*************************************************************************/ + + /** + * This method returns the current value of the index. + * + * @return The current index value + */ + public int getIndex () { - if (pos == end) - return CharacterIterator.DONE; - ++pos; - return current (); + return index; } - public char previous () + /*************************************************************************/ + + /** + * This method sets the value of the index to the specified value, then + * returns the character at that position. + * + * @param index The new index value. + * + * @return The character at the new index value or <code>DONE</code> + * if the index value is equal to <code>getEndIndex</code>. + * + * @exception IllegalArgumentException If the specified index is not valid + */ + public char setIndex (int index) { - if (pos == begin) - return CharacterIterator.DONE; - --pos; + if ((index < begin) || (index > end)) + throw new IllegalArgumentException ("Bad index specified"); + + this.index = index; return current (); } - public char setIndex (int idx) + /*************************************************************************/ + + /** + * This method returns the character position of the first character in the + * range. + * + * @return The index of the first character in the range. + */ + public int getBeginIndex () { - // In 1.1 we would throw an error if `idx == end'. - if (idx < begin || idx > end) - throw new IllegalArgumentException (); - pos = idx; - return current (); + return begin; } - public StringCharacterIterator (String text) + /*************************************************************************/ + + /** + * This method returns the character position of the end of the text range. + * This will actually be the index of the first character following the + * end of the range. In the event the text range is empty, this will be + * equal to the first character in the range. + * + * @return The index of the end of the range. + */ + public int getEndIndex () { - this (text, 0, text.length(), 0); + return end; } - public StringCharacterIterator (String text, int pos) + /*************************************************************************/ + + /** + * This method creates a copy of this <code>CharacterIterator</code>. + * + * @return A copy of this <code>CharacterIterator</code>. + */ + public Object clone () { - this (text, 0, text.length(), pos); + return new StringCharacterIterator (text, begin, end, index); } - public StringCharacterIterator (String text, int begin, int end, int pos) + /*************************************************************************/ + + /** + * This method tests this object for equality againt the specified + * object. This will be true if and only if the specified object: + * <p> + * <ul> + * <li>is not <code>null</code>. + * <li>is an instance of <code>StringCharacterIterator</code> + * <li>has the same text as this object + * <li>has the same beginning, ending, and current index as this object. + * </ul> + * + * @param obj The object to test for equality against. + * + * @return <code>true</code> if the specified object is equal to this + * object, <code>false</code> otherwise. + */ + public boolean equals (Object obj) { - if (begin < 0 || begin > end || end > text.length() - // In 1.1 we would also throw if `pos == end'. - || pos < begin || pos > end) - throw new IllegalArgumentException (); + if (! (obj instanceof StringCharacterIterator)) + return false; - this.text = text; - this.begin = begin; - this.end = end; - this.pos = pos; + StringCharacterIterator sci = (StringCharacterIterator) obj; + + return (begin == sci.begin + && end == sci.end + && index == sci.index + && text.equals (sci.text)); } - // The online 1.2 docs say that this is "package visible" in the - // method description, but they also say it is public. We choose - // the latter for compatibility with the actual implementation. + /*************************************************************************/ + + /** + * This method allows other classes in java.text to change the value + * of the underlying text being iterated through. + * + * @param text The new <code>String</code> to iterate through. + */ public void setText (String text) { this.text = text; this.begin = 0; this.end = text.length (); - this.pos = 0; + this.index = 0; } - - // String to iterate over. - private String text; - // Current position. - private int pos; - // Start position in string. - private int begin; - // End position in string. - private int end; } |
