gcc/libjava/java/text/StringCharacterIterator.java

143 lines
3.4 KiB
Java

// StringCharacterIterator.java - Iterate over string of Unicode characters.
/* Copyright (C) 1999 Free Software Foundation
This file is part of libgcj.
This software is copyrighted work licensed under the terms of the
Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
details. */
package java.text;
/**
* @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 ()
{
return (Object) new StringCharacterIterator (text, begin, end, pos);
}
public char current ()
{
// 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;
}
public boolean equals (Object obj)
{
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));
}
public char first ()
{
pos = begin;
return current ();
}
public int getBeginIndex ()
{
return begin;
}
public int getEndIndex ()
{
return end;
}
public int getIndex ()
{
return pos;
}
public int hashCode ()
{
// FIXME: this is a terrible hash code. Find a better one.
return text.hashCode() + pos + begin + end;
}
public char last ()
{
pos = end;
return current ();
}
public char next ()
{
if (pos == end)
return CharacterIterator.DONE;
++pos;
return current ();
}
public char previous ()
{
if (pos == begin)
return CharacterIterator.DONE;
--pos;
return current ();
}
public char setIndex (int idx)
{
// In 1.1 we would throw an error if `idx == end'.
if (idx < begin || idx > end)
throw new IllegalArgumentException ();
pos = idx;
return current ();
}
public StringCharacterIterator (String text)
{
// FIXME: remove check for null once we have compiler/runtime
// support for NullPointerException.
this (text, 0, text == null ? 0 : text.length(), 0);
}
public StringCharacterIterator (String text, int pos)
{
// FIXME: remove check for null once we have compiler/runtime
// support for NullPointerException.
this (text, 0, text == null ? 0 : text.length(), pos);
}
public StringCharacterIterator (String text, int begin, int end, int pos)
{
if (text == null)
throw new NullPointerException ();
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 ();
this.text = text;
this.begin = begin;
this.end = end;
this.pos = pos;
}
// 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;
}