/* Soot - a J*va Optimization Framework
* Copyright (C) 1997 Clark Verbrugge
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* Modified by the Sable Research Group and others 1997-1999.
* See the 'credits' file distributed with Soot for the complete list of
* contributors. (Soot is distributed at http://www.sable.mcgill.ca/soot)
*/
package soot.coffi;
import java.util.Enumeration;
/** An enumeration of a Utf8 allows one to run through the characters in a
* unicode string; used primarily for comparing unicode strings. Note that
* unlike regular enumerations, and to be efficient (ie to avoid allocating
* an object in each call to nextElement), the return value is accessed by
* this object's 'c' field, and nextElement merely returns this.
* @see CONSTANT_Utf8_info
* @see Utf8_Enumeration#c
* @see Utf8_Enumeration#nextElement
* @author Clark Verbrugge
*/
public class Utf8_Enumeration implements Enumeration {
/** The latest character, as determined by nextElement.
* @see Utf8_Enumeration#nextElement
*/
public int c; // latest character
private short curindex;
private short length;
private byte bytes[];
/** For creating an empty enumeration; you must use reset() after this
* to initialize the enumeration.
* @see Utf8_Enumeration#reset
*/
public Utf8_Enumeration() {}
/** For creating a normal enumeration of the given Utf8 string.
* @param b array of bytes in Utf8 format.
*/
public Utf8_Enumeration(byte b[]) {
bytes = b;
curindex = (short)2;
length = (short)(((((bytes[0]))&0xff)<<8) + (((bytes[1]))&0xff) + 2);
}
/** Resets this object to be an enumeration of the given Utf8 string.
* @param b array of bytes in Utf8 format.
*/
public void reset(byte b[]) {
bytes = b;
curindex = (short)2;
length = (short)(((((bytes[0]))&0xff)<<8) + (((bytes[1]))&0xff) + 2);
}
/** <i>true</i> if the entire string hasn't been enumerated yet. */
public boolean hasMoreElements() {
if (curindex<length) return true;
return false;
}
/** Determines the next Utf8 character, and stores it in c.
* @return <i>this</i>
* @see Utf8_Enumeration#c
*/
public Object nextElement() {
byte b;
b = bytes[curindex++];
if ((b&((byte)0x80))==0) { // one-byte character
c = b;
} else if ((b&((byte)0xe0))==0xc0) { // two-byte character
c = ((b&((byte)0x1f)))<<6;
b = bytes[curindex++];
c |= (b&((byte)0x3f));
} else { // three-byte character
c = ((b&((byte)0x0f)))<<12;
b = bytes[curindex++];
c |= ((b&((byte)0x3f)))<<6;
b = bytes[curindex++];
c |= (b&((byte)0x3f));
}
return this;
}
}