protected Op(int type) 
{
       
        this.type = type;
}

 static Op.CharOp createAnchor(int data) 
{
        if (Op.COUNT)  Op.nofinstances ++;
        return new CharOp(Op.ANCHOR, data);
}

 static Op.CharOp createBackReference(int refno) 
{
        if (Op.COUNT)  Op.nofinstances ++;
        return new CharOp(Op.BACKREFERENCE, refno);
}

 static Op.CharOp createCapture(int number,
    Op next) 
{
        if (Op.COUNT)  Op.nofinstances ++;
        CharOp op = new CharOp(Op.CAPTURE, number);
        op.next = next;
        return op;
}

 static Op.CharOp createChar(int data) 
{
        if (Op.COUNT)  Op.nofinstances ++;
        return new CharOp(Op.CHAR, data);
}

 static Op.ChildOp createClosure(int id) 
{
        if (Op.COUNT)  Op.nofinstances ++;
        return new ModifierOp(Op.CLOSURE, id, -1);
}

 static Op.ConditionOp createCondition(Op next,
    int ref,
    Op conditionflow,
    Op yesflow,
    Op noflow) 
{
        if (Op.COUNT)  Op.nofinstances ++;
        ConditionOp op = new ConditionOp(Op.CONDITION, ref, conditionflow, yesflow, noflow);
        op.next = next;
        return op;
}

 static Op createDot() 
{
       
        if (Op.COUNT)  Op.nofinstances ++;
        return new Op(Op.DOT);
}

 static Op.ChildOp createIndependent(Op next,
    Op branch) 
{
        if (Op.COUNT)  Op.nofinstances ++;
        ChildOp op = new ChildOp(Op.INDEPENDENT);
        op.setChild(branch);
        op.next = next;
        return op;
}

 static Op.ChildOp createLook(int type,
    Op next,
    Op branch) 
{
        if (Op.COUNT)  Op.nofinstances ++;
        ChildOp op = new ChildOp(type);
        op.setChild(branch);
        op.next = next;
        return op;
}

 static Op.ModifierOp createModifier(Op next,
    Op branch,
    int add,
    int mask) 
{
        if (Op.COUNT)  Op.nofinstances ++;
        ModifierOp op = new ModifierOp(Op.MODIFIER, add, mask);
        op.setChild(branch);
        op.next = next;
        return op;
}

 static Op.ChildOp createNonGreedyClosure() 
{
        if (Op.COUNT)  Op.nofinstances ++;
        return new ChildOp(Op.NONGREEDYCLOSURE);
}

 static Op.ChildOp createQuestion(boolean nongreedy) 
{
        if (Op.COUNT)  Op.nofinstances ++;
        return new ChildOp(nongreedy ? Op.NONGREEDYQUESTION : Op.QUESTION);
}

 static Op.RangeOp createRange(Token tok) 
{
        if (Op.COUNT)  Op.nofinstances ++;
        return new RangeOp(Op.RANGE, tok);
}

 static Op.StringOp createString(String literal) 
{
        if (Op.COUNT)  Op.nofinstances ++;
        return new StringOp(Op.STRING, literal);
}

 static Op.UnionOp createUnion(int size) 
{
        if (Op.COUNT)  Op.nofinstances ++;
        //System.err.println("Creates UnionOp");
        return new UnionOp(Op.UNION, size);
}

 Op elementAt(int index) 
{
                   // for UNIoN
        throw new RuntimeException("Internal Error: type="+this.type);
}

 Op getChild() 
{
                             // for CLOSURE, QUESTION
        throw new RuntimeException("Internal Error: type="+this.type);
}

 int getData() 
{
                             // CharOp  for CHAR, BACKREFERENCE, CAPTURE, ANCHOR, 
        throw new RuntimeException("Internal Error: type="+this.type);
}

 int getData2() 
{
                            // ModifierOp
        throw new RuntimeException("Internal Error: type="+this.type);
}

 String getString() 
{
                        // STRING
        throw new RuntimeException("Internal Error: type="+this.type);
}

 RangeToken getToken() 
{
                     // RANGE, NRANGE
        throw new RuntimeException("Internal Error: type="+this.type);
}

 int size() 
{
                                // for UNION
        return 0;
}