complab4 old NextTok

public Token nextToken() {
        while (-1 != cur.getCp()) {

            while (cur.isWhiteSpace() || cur.isNewLine())
                cur.nxt();

            Position start = cur.copy();    //avoid referencing object (otherwise changing 'cur' also changes 'start')

            switch (cur.getCp()) {
                case '/':

                    cur.nxt();
                    if ('*' != cur.getCp()) {

                        Position curCopy = cur.copy();
                        compiler.addMessage(true, curCopy, "unexpected character in comment: '" +
                                program.substring(cur.getIndex(), cur.getIndex() + 1) + "' found, '*' expected");
                    }

                    do {
                        do {
                            cur.nxt();
                        } while ('*' != cur.getCp() && -1 != cur.getCp());
                        cur.nxt();

                    } while ('/' != cur.getCp() && -1 != cur.getCp());

                    if (-1 == cur.getCp())
                        compiler.addMessage(true, cur, "end of program found, '*/' expected");

                    cur.nxt();

                    Position curCopy = cur.copy();
                    comments.add(new Fragment(start, curCopy));


                    break;

                default:
                    if (cur.isLetterOrDigit()) {

                        //string.matches("^(([a-z]{1}[0-9]{1})*[a-z]?)|(([0-9]{1}[a-z]{1})*[0-9]?)");
                        String tmp = "";
                        String idtName = "";
                        boolean letter = false, digit = false, mark = true;
                        if (cur.isLetter()) digit = true;
                        if (cur.isDigit()) letter = true;

                        while (cur.isLetterOrDigit()) {


                            //cur.nxt();
                            tmp = program.substring(start.getIndex(), cur.getIndex());
                            if (tmp.equals("for") || tmp.equals("if") || tmp.equals("m1")) {

                                KeyToken keytok = new KeyToken(start, cur);
                                System.out.println(keytok.toString() + tmp);

                                return keytok;
                            }


                            if (cur.isLetter()) {
                                if (digit) {
                                    letter = true;
                                    digit = false;
                                    idtName += (char)(cur.getCp());
                                    mark = true;
                                    //System.out.println("i:" + idtName);
                                    cur.nxt();
                                    continue;
                                }
                                if (letter) {
                                    mark = false;
                                    break;
                                    //compiler.addMessage(true, start.copy(), "unexpected character in ident");
                                }
                            }
                            if (cur.isDigit()) {
                                if (letter) {
                                    letter = false;
                                    digit = true;
                                    idtName += (char)(cur.getCp());
                                    mark  = true;
                                    //System.out.println("i:" + idtName);
                                    cur.nxt();
                                    continue;
                                }
                                if (digit) {
                                    mark = false;
                                    break;
                                    //compiler.addMessage(true, start.copy(), "unexpected character in ident");
                                }
                            }

                            cur.nxt();

                        }

                        if (mark) {
                            IdentToken tok = new IdentToken(compiler.addName(idtName), start, cur);
                            System.out.println(tok.toString() + idtName);
                            //cur.nxt();
                            return tok;
                        }
                        compiler.addMessage(true, cur.copy(), "unexpected character in ident");

                        /*if (tmp.matches("^(([a-z]{1}[0-9]{1})*[a-z]?)|(([0-9]{1}[a-z]{1})*[0-9]?)")) {

                            String identName = program.substring(start.getIndex(), cur.getIndex());

                            IdentToken tok = new IdentToken(compiler.addName(identName), start, cur);
                            System.out.println(tok.toString() + identName);

                            cur.nxt();

                            return tok;
                        }*/

                        //Position cur2 = cur.copy();
                        //compiler.addMessage(true, start, "unexpected character in ident");

                    }

                    break;
            }

            cur.nxt();
        }
        return null;
    }