//  Job: Jay's Own Browser, a web browser written in Java by Jay Skeer
//  Copyright (C) 1996 Jay Skeer, Jay Prime Positive
//
//  This program 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 of the License, or
//  (at your option) any later version.
//
//  This program 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 this program; if not, write to the Free Software
//  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//

import PushBackStringTokenizer;

public class myPushBackStringTokenizer {
    String unread_token= null;
    int read_position= 0;
    int to_tokenize_len= 0;
    char to_tokenize[]= null;
    String delimiters= null;
    boolean return_delims= false;

    public myPushBackStringTokenizer
	(String totok, String delims, boolean return_delims_p)
    {
	unread_token= null;
	read_position= 0;
	if (null != totok) {
	    to_tokenize_len= totok.length();
	    to_tokenize= new char[to_tokenize_len];
	    totok.getChars(0, to_tokenize_len, to_tokenize, 0);
	} else {
	    to_tokenize_len= 0;
	    to_tokenize= null;
	}
	delimiters= delims;
	return_delims= return_delims_p;
    }

    private boolean has_more_chars() {
	return (read_position < to_tokenize_len);
    }

    private char peek_char() {
	return (to_tokenize[read_position]);
    }

    private char next_char() {
	return (to_tokenize[read_position++]);
    }

    private boolean is_delim(char c) {
	return (0 <= delimiters.indexOf(c));
    }

    private void unread_token(String t) {
	unread_token= t;
    }

    public void unreadToken(String t) {
	unread_token(t);
    }

    private String next_token() {
	String rv= null;
//Jdb.enter("MPST.next_token()");
	if (null != unread_token) {
//Jdb.trace("re-read unread token");
	    rv= unread_token;
	    unread_token= null;
	} else if (this.has_more_chars()) {
	    if (return_delims && is_delim(peek_char())) {
		rv= (new Character(next_char())).toString();
//Jdb.trace("return delim token");
	    } else {
		while ((this.has_more_chars())
		  &&  (is_delim(peek_char())))
		{
//Jdb.trace("skip delim token(s)");
		    next_char();
		}
		rv= new String();
		while ((this.has_more_chars())
		  &&  (! is_delim(peek_char())))
	        {
		    rv= rv + next_char();
		}
//Jdb.trace("return non-delim token");
	    }
	}
//Jdb.exit("MPST.next_token() => " + rv);
	return rv;
    }

    public String nextToken() {
	return next_token();
    }

    private String peek_token() {
	String rv= null;
	if (null != unread_token) {
	    rv= unread_token;
	} else {
	    rv= next_token();
	    unread_token(rv);
	}
	return rv;
    }

    public String peekToken() {
	return peek_token();
    }

    public boolean hasMoreTokens() {
	boolean rv= false;
	if (null != unread_token) {
	    rv= true;
	} else {
	    String s= peek_token();
	    if (null != s) {
		rv= true;
	    }
	}
	return rv;
    }
}