package binaryTree.visitor;

import binaryTree.*;

import stacks.*;

import java.util.Enumeration;

public class InorderEnumeration implements IVisitor, Enumeration {

    public InorderEnumeration(BiTree tree)
    {
	tree.execute(this, null);
    }

    public boolean hasMoreElements()
    {
        return stack.isEmpty() == false;
    }

    public Object nextElement()
    {
        BiTree current = (BiTree) stack.pop();

	current.getRightSubTree().execute(this, null);

        return current.getRootDat();
    }

    public Object emptyCase(BiTree host, Object input)
    {
	return null;
    }

    public Object nonEmptyCase(BiTree host, Object input)
    {
	stack.push(host);

	return host.getLeftSubTree().execute(this, input);
    }
        
    LRSStack stack = new LRSStack();
}